Sciencemadness Discussion Board

Hydrazine

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Rosco Bodine - 21-5-2007 at 10:35

@ garage chemist

About the urea method , I was wondering if you tried using the urea as a slurry like the patent described , instead of as a 50% solution .....thinking that perhaps the water content for a 50% solution might be what is causing the stability problem due to the competing reaction of the chlorine with water .

Also I have been thinking more about the possibility of using TCCA plus CaCl2 in an analogous manner as the salt plus TCCA reaction for producing chlorine , still thinking that perhaps simply adding NaOH solution dropwise to a stirred mixture of TCCA suspended in CaCl2 , may result in a strong solution of bleach over precipitated calcium cyanurate .

What I was thinking was a solubility driven reaction
summarized here :

[ 2 TCCA + 3 CaCl2 ----> 6 Cl2 + Ca3(OCN)6 ]

[ 12 NaOH + 6 Cl2 -----> 6 NaOCl + 6 NaCl + 6 HOH ]

2TCCA + 3CaCl2 + 12NaOH ----> 6NaOCl + 6NaCl + Ca3(OCN)6 + 6 HOH

I was looking at the possibility of using sodium dichloroisocyanurate in a similar way but realized the
equation doesn't quite balance .....so I will have to give that one some more thought .


[Edited on 21-5-2007 by Rosco Bodine]

garage chemist - 21-5-2007 at 12:58

Having recently acquired 5kg of 70% Ca(OCl)2 from ebay, and with TCCA being significantly more expensive than it, I will use the calcium hypochlorite as the chlorine source in my hydrazine experiments.

TCCA only liberates hypochlorite when reacted with strong NaOH solution. I dont know if Ca(OH)2 solution is alkaline enough for it.
Also, if you have rather concentrated solutions of calcium salts, you cant simply precipitate it by adding an anion that forms an insoluble calcium salt. It will turn into goop instead, probably making the kneading process I described for getting NaOCl from Ca(OCl)2 necessary as well.

Maybe someone else has the time to do experiments on how to obtain strong NaOCl solution from TCCA, as I dont have it.
It would definately be interesting.

Rosco Bodine - 21-5-2007 at 13:37

I think the TCCA reaction would work , but very slowly
due to low solubility of the TCCA and especially because
heat could not be used to drive the reaction .

And yeah the voluminous precipitate of calcium salts is usually a headache , requiring a filter press or a
"twisting the chesecloth" manipulation to squeeze the
solution from the mush .

The alternative is generating free chlorine and chlorinating a cold NaOH solution . So it is going to be something of a nuisance in one way or the other ,
by either approach .

I think if the calcium cyanurate as a byproduct was a goal it would probably be easier just to go with a chlorine generation scheme for the NaOH , and then neutralize
the HCl and cyanuric acid residue in the chlorine generator with washing soda or bicarbonate , and then
add CaCl2 solution to precipitate the calcium cyanurate .

Anyway it was just an idea , but I suppose the manipulation difficulties and temperature limitations
would make it impractical , even though on first thought it seems like a good idea .

Hydrazine Amalgam

Rosco Bodine - 4-6-2007 at 19:52

Just when you thought you knew a few things about hydrazine ....hmmm ,
then you learn it thinks it is a metal ,
and sooooo of course it forms amalgams :D

This is really pretty neat , totally wierd ,
and possibly also very useful .

[Edited on 4-6-2007 by Rosco Bodine]

Attachment: US3301773 Hydrazine from Hydrazine Amalgams via Electrolysis.pdf (271kB)
This file has been downloaded 1118 times


not_important - 4-6-2007 at 20:17

Like ammonium amalgam, except more stable it appears.

tito-o-mac - 2-7-2007 at 03:16

Does anyone here know anything on how to make alminium hydrazine?

More on Hydrazine

franklyn - 23-7-2007 at 13:11

From Ye old rhodium apothecary
http://designer-drug.com/pte/12.162.180.114/dcd/chemistry/hy...

Of course you can always just buy the Sulfate, just don't pay more than 15 cents per gram ;) ( extra with shipping )
http://www.advance-scientific.net/Properties.asp?code=H1019+...

P.S.
@ tito-o-mac
aluminum hydrazine is not a componud , it is a suspension of aluminum dust and anhydrous hydrazine.
Hydrazine hydrate will slowly combine the aluminum with the water into aluminum hydroxide releasing
hydrogen gas until all that remains is anhydrous hydrazine over the aluminum hydroxide precipitate.
Not good if this happens in a closed container having hydrogen under pressure over anhydrous hydrazine.
VERY - B I G - B O O M , house falls back to earth as blizzard of sawdust.

_______________________________________________________________

U P D A T E

Note that my assertion above may be unfounded. Draw your own conclusions.
Quoted from page 392 of Corrosion of Aluminium
posted here _
http://www.sciencemadness.org/talk/viewthread.php?tid=8706&a...

Pure hydrazine and its derivatives monomethylhydrazine (MMH) CH3NHNH2 and
dimethylhydrazine (DMH) (CH3)2NNH2 have no action on aluminium in a wide
range of temperatures between -196 and +27 ºC [14].
Hydrazine solutions have no action on aluminium; the annual decrease in thickness
in solutions at 5 and 10% is below 1 mm.
Hydrazine and its derivatives are not decomposed or altered in contact with aluminium
alloys [15].
This makes it possible to manufacture the tanks of rockets in aluminium alloys
such as 6061. Tests have shown that this alloy is not prone to stress corrosion in
hydrazine [16].

[15] Van der Wall E.M., Suder J.K., Beegle R.L., Cabeal J.A., Propellant/Material compatibility
study, AFRPL, report TR-71-741.
http://stinet.dtic.mil/cgi-bin/GetTRDoc?AD=0736464&Locat...
[16] Gilbreath P., Adamson M.J., The stress-corrosion susceptibility of several alloys in hydrazine
fuels, NASA, report TN D-7604, February 1974.
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/1974000...

Edited on 25-12-2007
- - - - - - - - - - - - - - - - - - - -

More Curious observations from various sources _

Investigations on the reaction between aluminum and hydrazine have produced
discordant results. However, at least under some conditions, hydrazine has
caused corrosion of aluminum. This corrosion is dependent on the aluminum alloy,
the hydrazine purity and the temperature.

In normal environments aluminum is covered by a protective oxide layer. The
solubility of this oxide in water is very low but is increased in acidic or alkaline
solutions. The oxide is very hard to reduce. For example,the free energy change,
for the reaction 3 N2H4 + 2 Al203 = 3N2 + 6H20 + 4Al, is +321 Kcal. With such a
high positive free energy change, the reduction by hydrazlne is not found.

The solubility of aluminum or aluminum oxide in hydrazine appears to be very slight.
However, when hydrazine was stored in 2014 aluminum, a precipitate was
observed containing aluminum and copper. This dissolution and precipitation
appears to be similar to corrosive reactions in water where there is local solubility
followed by precipitation of the dissolved product.


A commonality exists between solutions of water and carbon dioxide in hydrazine
in that both are sources of protons _

H20 + N2H4 = N2H5(+) + OH(-)

CO2 + N2H4 = H2N2HCOO(-) H(+)

The latter product, carbazic acid, is probably more correctly characterized in
excess hydrazine as the hydrazinium salt, H2N2HCOO(-)N2H5(+). The hydrazinium
ion, N2H5(+), in hydrazine is the analog in properties of the hydronium ion, H30 +,
in water. Simplistically. a measure of the hydrazinium ion concentration may be
calculated for systems containing the two impurities by using the equilibrium
constant for reaction (1), K298 = 8.5X10-7, s and assuming for reaction (2) that
carbazic acid is a strong acid and the CO2 reaction with N2 H4 is complete. Thus,
for small amounts of water, the hydrazinium ion will be proportional to the
half-power of the water concentration and at a 1 percent impurity level would be
7×10 -4 M. Assuming complete ionization, the hydrazinium ion concentration in
reaction (2) is directly proportional to the carbon dioxide impurity

It is expected that the hydrazine salt of carbazic acid will ionize in hydrazine as
N2H5(+) and N2H3C00(-). If the N2H5(+) ion is the reactive or catalytic species
in the carbazic acid catalyzed decomposition of hydrazine, this would be in
agreement with the previous observation that, of the other additives tested, only
water increased the decomposition rate.


[Edited on 3-1-2008 by franklyn]

12AX7 - 23-7-2007 at 14:32

Hydrazine is basic, eh? That would corrode aluminum quite nicely in the presence of water, yes!

Tim

Sauron - 24-7-2007 at 07:57

@tito-o-ma, mess around w/anhydrous hydrazine at age 14 and you won't make it out or four teens.

CARCINOGEN.

Much more on Hydrazine

franklyn - 25-7-2007 at 02:45

The original 1906 Raschig process combining aqueous ammonia and hypochlorite
in gelatin remains the most amenable to the small scale production of Hydrazine.
A detailed outline on how to do this yourself is here below.
In 1907 Olin modfied this process for industrial scale to be done in two steps to
eliminate the need for gelatin. Other different Industrial processes that have
also seen use are , Hoffman (Urea) process , Bayer (Ketazine) process, Atofina
(Peroxide) process , brief descriiptions are in the attached *.zip file
as well as physical data on ammonia and hydrazine.
More references are below here.

__________________________


1. Preparation of NaClO
A NORMAL solution of sodium hypochlorite is prepared as follows: in a 5-liter
round-bottom flask are placed 1800 g. of sodium hydroxide solution (300 g. of
sodium hydroxide to 1500 g. of water) and 1500 g. of ice. Chlorine gas is then
passed into the solution until it has gained in weight approximately 213 g.
During this addition, the solution must be kept thoroughly cooled with ice, in
order that chlorates will not be formed. After all the chlorine has been passed
in, it is necessary to be certain that the mixture is slightly alkaline, since any
excess of free chlorine in the solution prevents the formation of hydrazine.


Preparation of Hydrazine Sulfate or the hydrate


2. Procedure
In a 14-inch evaporating dish are placed 1500 cc. of c. p. ammonia water (sp. gr. 0.90),
900 cc. of distilled water, 375 cc. of 10 per cent gelatine solution, and 1200 cc. of the
normal sodium hypochlorite solution prepared as above.
This mixture is heated as rapidly as possible and boiled down until one-third of the original
volume is left. This solution is then cooled thoroughly with ice and filtered with suction,
first through two layers of toweling and then through one thickness of ordinary filter paper
over cloth, in order to remove finely divided solid impurities. The solution is then placed in
a precipitating jar, and cooled down thoroughly (0'0) with ice and salt; 10 cc. of
concentrated sulfuric acid for each 100 cc. of solution are gradually added with constant
stirring. A precipitate of hydrazine sulfate (NH2NH2<.>H2SO4) forms. The mixture is
allowed to stand in the cold for a few hours in order to complete the precipitation, and is
then filtered by suction in the usual way and washed with cold alcohol. The yield varies
from 53 g. to 58 g. per 1500 cc. of ammonia water (34-37 per cent of the theoretical
amount). The product is perfectly white and crystalline, and satisfactory for almost any
purpose. If an absolutely pure product is desired, it must be recrystallized from water. For
every 21 g. of crude product, 100 g. of boiling water are used. If the crude precipitate is
brown, it is advisable to use a little bone-black. After the mixture has been filtered and
cooled to 0'0, 19 g. of pure white crystals are obtained.


3. Notes
In the preparation of the sodium hypochlorite solution it is quite necessary that the
mixture be kept cold and be alkaline to red litmus paper at the end of the reaction,
if good yields of hydrazine are to be obtained.

Since iron is an anti-catalyzer, it is necesssary{sic} to use distilled water throughout
the process.

As a viscolizer, a substance such as starch, glycerol, glue or gelatine may be used;
the last, however, gives by far the most satisfactory results.

In order to obtain a pure white hydrazine sulfate as the first precipitate, it is necessary
to cool the hydrazine solution thoroughly and filter it twice before the sulfuric acid is
added. Moreover, the sulfuric acid must be added slowly and with stirring. If these
conditions are not followed, material containing brown particles results.

The mother liquor obtained from the crystallized hydrazine sulfate contains a
small amount of hydrazine.

_______________________________________________________________


Other Methods of Preparation

Hydrazine salts have been prepared by the action of hypochlorites on ammonia[1] or urea;[2]
by the hydrolysis of salts of sulfohydrazimethylene disulfonic acid;[3]
by the hydrolysis of triazoacetic acid;[4]
by the reduction of diazoacetic ester;[5]
by the reduction of nitroguanidine followed by hydrolysis;[6]
by the reduction of the nitroso derivatives of hexamethylene tetramine;[7]

by the reduction of nitrates or nitrites with zinc in neutral solution;[8]
by the action of sodium bisulfite on hyponitrous acid followed by reduction;[1b]
by the reduction of K2SO3N2O2;[2b]
by the action of ammonia on dichlorourea;[3b]
by the reduction of nitrosoparaldimin;[4b]
by the action of copper sulfate on ammonia at high temperatures;[5b]
by the reduction of methylene diisonitrosoamine;[6b]
by the hydrolysis of the addition product of diazoacetic ester and fumaric or cinnamic esters.[7b]


[1] D. R. P. 192,783; Chem. Zentr. 1908 (I), 427; Chem. Ztg. 31, 926 (1907); D. R. P. 198,307;
Chem. Zentr. 1908 (I), 1957; Eng. Pat. 22,957; C. A. 2, 1999 (1908); U. S. Pat. 910,858;
C. A. 3, 1065 (1909); French Pat. 382,357; C. A. 3, 2358 (1909); Ber. 40, 4588 (1907);
Laboratory Manual of Inorganic Preparations, by A. B. Lamb, Harvard University, Cambridge, Mass.

[2] J. Russ. Phys. Chem. Soc. 37, 1 (1905); Chem. Zentr. 1905 (I) 1227; D. R. P. 164,755;
Frdl. 8, 53 (1905); French Pat. 329,430; J. Soc. Chem. Ind. 22, 1063 (1903);
Chem. Zentr. 1905 (I) 1227.

[3] D. R. P. 79,885; Frdl. 4, 26 (1895); Ber. 28, 2381 (1895).

[4] Ber. 20, 1632 (1887); Chem. News 55, 288 (1887); D. R. P. 47,600; Frdl. 2, 554 (1889);
J. prakt. Chem. (2) 39, 27 (1889).

[5] Ber. 27, 775 (1894); 28, 1848 (1895); D. R. P. 58,751; Frdl. 3, 16 (1891); D. R. P. 87,131;
Frdl. 4, 28 (1896).

[6] Ann. 270, 31 (1892); D. R. P. 59,241; Frdl. 3, 16 (1891); Eng. Pat. 6,786;
J. Soc. Chem. Ind. 11, 370 (1892).

[7] D. R. P. 80,466; Frdl. 4, 27 (1895); Ann. 288, 232 (1895).



[8] Eng. Pat. 11, 216; J. Soc. Chem. Ind. 14, 595 (1895).

[1b] Ber. 33, 2115 (1900); Ann. 288, 301 (1895).

[2b] Ber. 27, 3498 (1894).

[3b] J. Chem. Soc. 95, 235 (1909); Chem. News 98, 166 (1908).

[4b] Ber. 23, 752 (1890).

[5b] Chem. News 66, 223 (1892).

[6b] Ber. 27, 3292 (1894);

[7b] Ber. 21, 2637 (1888).

__________________________________________________________


A microwave process
http://www.rsc.org/publishing/journals/article.asp?doi=f1972...

J. Chem. Soc., Faraday Trans. 1, 1972, 68, 315 - 322, DOI: 10.1039/F19726800315

Decomposition of ammonia in a microwave discharge
by R. Barker

Abstract
Ammonia is decomposed in a microwave discharge to give hydrazine, nitrogen and hydrogen. Product yields have been measured as a function of ammonia flow-rate, pressure, power input, temperature and added allyl alcohol and propylene. Hydrazine yields are increased with these additives, although the effect falls off at high powers, whereas gas yields (which approximate to the overall ammonia decomposition) are not appreciably affected. Kinetic and analytical evidence shows that the effect of allyl alcohol in increasing the hydrazine yield is by scavenging H atoms and that few NH2 radicals are scavenged. The remaining hydrazine destruction mechanism (particularly at high power) is probably electron-induced.


__________________________________________________________

.

Attachment: Hydrazine properties.zip (459kB)
This file has been downloaded 924 times


Rosco Bodine - 25-7-2007 at 04:16

Quote:
Originally posted by franklyn
The original 1906 Raschig process combining aqueous ammonia and hypochlorite
in gelatin remains the most amenable to the small scale production of Hydrazine.


On which planet ? Not on this earth , that's for damn sure .

Unbelievable , *absolute* crap ( without *any* qualification ) . PERIOD .

Urea

MadHatter - 25-7-2007 at 16:43

Roscoe, I'll agree with you on one point. The Raschig process will not be as
efficient as urea/gelatine/calcium hypochlorite process. Besides, I don't care
for the smell of ammonia !

Rosco Bodine - 25-7-2007 at 21:29

Yeah , the literature really needs to be updated with regards to what are convenient lab methods based on urea . That old ammonia process keeps coming up like a bad penny even though it is way less productive and
way more cumbersome . It gives the impression that the
powers that be simply don't want it well known just how easy it is to make hydrazine ....so they misdirect and misinform ....answering inquiries with directions to
the long and winding road rather than the quick and easy path .

Polverone - 25-7-2007 at 22:09

Quote:
Originally posted by Rosco Bodine
Yeah , the literature really needs to be updated with regards to what are convenient lab methods based on urea . That old ammonia process keeps coming up like a bad penny even though it is way less productive and
way more cumbersome . It gives the impression that the
powers that be simply don't want it well known just how easy it is to make hydrazine ....so they misdirect and misinform ....answering inquiries with directions to
the long and winding road rather than the quick and easy path .

More likely the "powers that be" just don't care about better small-scale procedures because institutionally affiliated chemists buy hydrazine that was made on an industrial scale. A lot of Inorganic Syntheses and Organic Syntheses, particularly earlier volumes, describes materials that usually enter the laboratory via delivery service today.

Sauron - 26-7-2007 at 03:12

Org.Syn. came into existance when there was no US manufacturing chemical industry and researchers were dependent on German suppliers. This supply line was disrupted by WWI. This resulted in the creation of Eastman's organic-chemical manufacturing operations in Rochester and also in the decision by Roger Adams and the other founders of Org.Syn. that a need existed for reliable and checked preparative procedures to be collected and regularly published so that researchers could prepare their own reagents.

The first annual volume appeared in 1921.

Over the years and decades that followed the emphasis of Org.Syn.'s editorial policy shifted. American researchers were no longer forced to prepare their own reagents. The careful preparative detail and the checking procedures remained, but the target compounds became more a matter of current trends in synthesis rather than basic building blocks. You can see the scale of the preparations roll back over time as well.

No one at Org.Syn. (or Wiley) is suppressing anything about hydrazine, it's simply that the procedure has not been updated since the 1920s and perhaps no one has submitted a hydrazine prep using the urea route. Org.Syn. does publish novel preparations of previously covered reagents from time to time.

Rosco Bodine - 26-7-2007 at 07:14

Maybe they just weren't paying attention ,
or else the publications rely entirely on voluntary
contributors .....and nobody gave :D

Somehow the "newer" (of that time) practical lab method fell through the cracks and didn't make it into the more prominent general references , though there is a sprinkling of references in chemical abstracts over the years to the urea
method .

The urea and hypochlorite method was published 1921 in German , and patents issued in Britain and the US , France and Germany soon after . Attached is a US patent from 1931 .

In 75 years since then , it seems to be glaring omission that
the "newer" content wouldn't have appeared in the texts and lab manuals which were still describing the older method
even after the newer method was available . Maybe it was just a lapse in keeping current on what is state of the art ,
which somehow escaped correction in newer publications ,
so the older process became enshrined as standard when it
ought not to have remained standard but updated long ago .

It still seems strange that a material like hydrazine would enjoy that sort of obscurity for so long .....but I have some
"period texts" from that era which fail to place emphasis on the updated method m so there is a sort of institutionalized
ignorance in play , whether it was deliberate , or not .

Attachment: US1959503 Hydrazine via Urea and Hypochlorite , Merck , circa 1931.pdf (108kB)
This file has been downloaded 1221 times


Sauron - 26-7-2007 at 09:42

Then Polverone's explanation comes into play. Academic and industrial labs judt buy he stuff. Here hydrazine hydrate gets sold in 25 L pails.

Rosco Bodine - 26-7-2007 at 09:46

I think academic sloppiness gets the prize .

They just dropped the ball on this one .

[Edited on 26-7-2007 by Rosco Bodine]

and the band played on

franklyn - 26-7-2007 at 20:20

:D Alright men , so who is planning to re-instate the Titan II missile ?
Sure , for industrial scale there are more streamlined methods.
I believe that most if not all are mentioned in those references I listed.
http://www.sciencemadness.org/talk/viewthread.php?tid=1128&a...
For the do it yourself amateur 1/2 a liter of stuff is surely sufficient and
a working recipe is invaluable. Granted that Brauer is dated , but Raschig
is , if somewhat abreviated , the method of preparation it outlines.
90 % of the items online refer to Raschig also , the remainder invoke the
Hoffman urea approach. You need to search graduate chemistry texts to
even see any mention of others. Thats been my experience.

To a casual viewer this nine page long thread of tweaks is reminiscent of
that " phorone " debacle with hardly anything identifiable as a process ,
something is dignified as such only when it is reproducible by others and
verifiably peer reviewed. If the newer means developed here are so much
better , in terms of yield perhaps , how could anyone tell , and how would
they know it ? I offer the example of the preceding half page of banter and
water cooler small talk ( isn't there a whimsy section for that ) Not a wit of
on topic information and a single citation hardly more than an abstract
exhumed from the attic of the Patent and Trademark Office , not exactly a
peer reviewed validation. Not surprising my opening remark was interpreted
as a dismisal by the " Hydrazine conspiracy " of whatever meaningful work
preceded in this thread .

Grumbled expletives are not informative , nor can I fathom such umbrage.
I'm reminded of the scene from the motion picture " Dr. Strangelove "
when the president ( Peter Sellers ) is on the red phone to the premier of
U.S.S.R., and exclaims " keep your feet on the ground when you're talking
Demitre , keep your feet on the ground Demitre , of course this is a friendly
call Demitre , ". In between invective tirades , Roscoe Bodine communicates
to me the following _
" I *already* have given references , along with details and experimental
results based on a small scale adaptation of the Merck patent process
involving sodium hypochlorite and urea. " ( in other words , can you spot
Waldo ? or is it Mr. Anonymous ) Amazingly this still hasn't been cited.
It would have better served everyone to just point this out in the first place
with a reprove that I am out of date and uninformed. As it is , anyone just
tuning in is left wondering what in the world is this soap opera all about.
Does this sound at all familiar to anyone ?

N E W - B E S T . H Y D R A Z I N E . P R E P A R A T I O N . ( so I am told )

http://sciencemadness.org/talk/viewthread.php?tid=757#pid653...
http://sciencemadness.org/talk/viewthread.php?tid=757#pid656...

______________________________________________________

P.S.
If anyone is interested I'll post my patent ( pending ) method
for hydrazine by electrolysis of sodium amide in liquid ammonia :D

.

Rosco Bodine - 26-7-2007 at 22:18

It's such an irony isn't it , when the state of the art is
right in front of you while you are looking everywhere else for it ! We are talking about an 86 year old technology as compared with a 101 year old technology .
If you are just wanting to be primitive , stick with the genuine antique ....crank the engine using the hand crank instead of trusting in the newfangled electric starter:D

Try this . If you need a few hundred grams of hydrazine sulfate for experimentation , and you are going to synthesize it instead of ordering it from a supply house ,
then your easiest route will be the improved hydrazine synthesis , by waldo , mr. anonymous , or rosco :D

Take it to the peer review court of your choice and
dispute the validity of my detailed description of a valid *lab scale* synthesis for which a dozen personally done experimental confirmations is sufficient for me . And a few others here have confirmed the synthesis . It's just tough to beat what's best ...like it's hard to be humble when you know you are great :D

There is nothing about this thread that compares with the phorone peroxide fraud thread , except for people who jump in to solve problems they seem to be the last to know are already solved .....for not having read the thread .

I completely stand by what I have already said .
If you have a problem with Merck and their reputation ,
then go to Darmstadt and take it up with them ,
because when you have successfully impeached their
75 year old patented synthetic process for hydrazine ,
then you will have discredited mine as well . Until then ,
what I have reported and the "tweaks" as you call them
are still state of the art for a lab method , and in effect were already "peer reviewed" 86 years ago ( by the peers who matter anyway :P ) What I can't fathom is why you can't seem to understand that , or why it would seem surprising to you that it would be pointed out / published here . It wasn't just a piece of chemistry trivia dredged up for no particular reason . The forum owner expressed an interest in the information and so I elaborated on it .

The hydrazine sulfate is a precursor of particular interest in connection with azides and tetrazoles , therefore an
efficient synthesis for it is useful , essential actually , for anyone having an interest in total synthesis of such materials .

not_important - 26-7-2007 at 23:47

Quote:
[quote[
Over the years and decades that followed the emphasis of Org.Syn.'s editorial policy shifted. American researchers were no longer forced to prepare their own reagents...


Quite true. In O.S. and I.S., and a number of practical or laboratory technique books as well, you can see this happening of several decades. Newer versions of a book would often have notes at the start of a preparation stating that "compound XYZ is now commercial available ", and that preparation would be absent from the next edition.

Sauron - 27-7-2007 at 00:16

I have never seen a prep deleted from Org.Syn. Almost every compound described in Org.Syn. since 1921 is and has been for 50-60-70 years or more, commercially available. Org.Syn. is organized in annual volumes and every decade, Collective Volumes. I have seen safety warning appended to previously published preps, I have seen newer preps of previously covered compounds, but I do not recall ANY compound, once its prep has been published in Org.Syn., every having been cut from subsequent editions (reprints) of the Collective Volumes (annual volumes do noit get reprinted.)

For example, t-butyl azidoformate was described in at least two seperate preparations, at a time when it seemed to be the N-Boc reagent of choice for peptide chemistry. Subsequently it went out of fashion because it was explosive, and because better N-Boc reagents appeared such as Boc-ON. However the preparations of t-Bu azidoformate are still presented in the online Wiley free edition of CV 1 through 10 and I am sure they are also in the hard copy.

I don't question that in some text, somewhere, what you are saying may be happening. But I challenge you to show me an example from Org.Syn.

Org.Syn. was never intended to be a manual for kitchen chemistry any more than Vogel was/is. The rationale of its inception and the evolution of its editorial policies over time have been described in various introductory sections and biographies or memorials to late editors. It was intended to assist working professional chemists in industry and academia. You won't find a word in there about garage chemistry, and in fact since they have been touting ACS "Prudent Practices" in every preparation for a long time now, they would seem to have slammed the door on amateurs formally.

None of that prevents these books from being useful to amateurs. It is just unrealistic to expect them to be comprehensive, or to update every prep they visited since 1921. It might be more apropos to criticize someone like Vogel who cribbed so much straight from Org.Syn., for omitting a better procedure that came up in the decade after one was published in Org.Syn., but was still in time for his bppk. However IIRC Vogel did not describe the prepration of hydrazine at all.

S.C. Wack - 27-7-2007 at 03:15

But was the use of urea ever published as an experimental in an article? The literature sources mentioned above take their cue from previously published work, and patents don't count. Not a whole lot of journal (other than IEC, for instance) or lab manual authors read, cite, or experiment from patent literature, so it is hardly a surprise. The only article where urea is used that I know of is in Safybi, which pretty much defines obscure. It is not completely absent from the available lab manuals, it appears in Vorobyova, which is of course translated from Russian.

Rosco Bodine - 28-7-2007 at 07:28

Similar omission scenarios exist where gaps in the literature , for whatever reason lead to what I call
"lost art" . This leaves many contemporary chemists
unknowledgeable about even the existence of the prior art since it can't easily be found by a search ...may never have even been indexed . The body of literature is so vast that this is not a rare occurence even for well known compounds . Patents are something I spend a fair amount of time reading because the data is easily searchable and extensive , generally reliable , and often references related material , and by law requires a search of related art by the examiners who then add their own
notes to the applicants . I see a few people making disparaging remarks about patents reliability , and yet a journal article can't be defended in court as a legal claim ,
while a patent most definitely can ....so which has the greater validity legally and technically ? The academic basis certainly has reason to be there for a paid publication which costs the submitter several thousand dollars to register as a legal document ....claiming the disclosed technology as being their intellectual property ,
that is their *invention* and more than any published reasearch finding .....although it is usually that also .
Often there are patents directly associated with the author of a journal article parallel to the patent and a search for author as inventor will turn up hits . But often it is also the case that the patent alone exists as the means of publication , and chemical abstracts lists these
patents ....even if there is no associated journal article ,
the patent speaks for itself dressed in the lawyers suit , even without a crew of labcoats affirming its validity :D

unionised - 15-8-2007 at 05:26

Hm?
OK have a look at this.
http://www.freepatentsonline.com/4455816.html

Now your question was "a journal article can't be defended in court as a legal claim ,
while a patent most definitely can ....so which has the greater validity legally and technically ?"
Well, there are 2 answers as I see it. Legally the patent wins; technically... you just wouldn't see that in a technical paper.
There is no requirement for a patent to work. Methods wriitn up in peer revoied journals do usually work- those that don't get lost in history.
There are often good reasons why, even for perfectly good ideas, some vital details are left out of patent descriptions. Most notably it makes it more difficult for someone to pirate the idea.

franklyn - 17-8-2007 at 14:36

Apples and oranges only make a good sangria. Patents are essentially
exclusive business licenses and an article of commerce that inherently
seeks to retain proprietary it's described process or proceedure .
Journals are written for the disclosure of discovery and do not withhold
confidential know how. The later is for fame , the former is for fortune.

.

Douchermann - 24-12-2007 at 21:08

Sorry to bring a thread up from the dead, but would performing the reaction in something other than glass affect it in any way? The reason I'm asking is because the biggest glass piece I have is a 1000ml flask, and with the foaming, that wont be sufficient. However, I have a 5 gallon (18 liter) aluminum pot that I could heat quite easily. If the aluminum pot affects it negatively, then I guess a Teflon coated cast iron pot would be out of the question too, correct?

higher yields of hydrazine?

YeOldeImpurities - 17-1-2008 at 14:22

Compounds of manganese (sulfate, chloride of manganese, permanganates...) in hypochlorite/urea/hydroxide reaction work better than gelatine. They give 5-10% higher yields of hydrazine than mixtures with gelatine. --- this I remember from book "The Chemistry of Hydrazine" by Audrieth and Ogg.
In russian book Греков,Отрошко: "Гидразинометрия" 1981 (Hydrazinometry by Grekov and Otroshko) is a recipe for making hydrazine sulfate with MnSO4.5H2O instead of gelatine (0,3 grams of MnSO4.5H2O to 15 grams of urea, yield 23 grams of hydrazine sulfate).
And also something else for increasing yields- in book Брикун,Козловский,Никит& #1080;на: "Гидразин и гидроксиламин и их применение в аналитической химии" 1967 (Hydrazine and hydroxylamine nad their application in analytical chemistry by Brikun, Kozlovskiy and Nikitina) is this: best compounds for protection of hydrazine/water solutions against oxidizing by air are oxides of calcium, zinc, aluminium and magnesium but the far superior is sulfur in small amounts. btw there is mentioned a method for producing hydrazine by dry destillation of urea/iron powder at 132-150ºC at atmospheric pressure.

not_important - 17-1-2008 at 19:26

Quote:
Originally posted by Sauron
I have never seen a prep deleted from Org.Syn....
I don't question that in some text, somewhere, what you are saying may be happening. But I challenge you to show me an example from Org.Syn.
...


Sorry, missed this reply back when it was done

Not that the actual earlier prep is deleted, but especially in the earlier collected series you would see mention made that XYZ was now commercially available, and either stated or implied that DIY wasn't worth it.

OS and IS don't change their reprints, the data remains unchanged. However textbooks do drop entries, I've several cases of multiple editions of the same book where some preparations were dropped and usually new ones added. And before OS was available online, textbooks were more likely to be found as affordable used books.

There's also changes in reagents across time. In the organic world it was typical to see an old method be dropped for one using a more exotic reagent but giving higher yields and/or more easily isolatable product. Over in the inorganic world an example in 'practical' books was in the preparation of HBr; first the SO2 and H2S routes disappeared, leaving just the red phosphorus method, then the preparation was dropped entirely as HBr became an easy to obtain reagent. But nowadays an amateur experimenter may not be able to purchase HBr, not unlikely for liability issues, not able to buy phosphorus because of legal restrictions, and thus be looking for those old alternatives that don't get mentioned in modern books.

not_important - 17-1-2008 at 19:44

Quote:
Originally posted by Douchermann
Sorry to bring a thread up from the dead, but would performing the reaction in something other than glass affect it in any way? The reason I'm asking is because the biggest glass piece I have is a 1000ml flask, and with the foaming, that wont be sufficient. However, I have a 5 gallon (18 liter) aluminum pot that I could heat quite easily. If the aluminum pot affects it negatively, then I guess a Teflon coated cast iron pot would be out of the question too, correct?


The metal pot might react with the alkali, the non-stick coating if new should be OK.

len1 - 18-1-2008 at 00:30

Quote:
There are often good reasons why, even for perfectly good ideas, some vital details are left out of patent descriptions. Most notably it makes it more difficult for someone to pirate the idea.


Maybe, but this strikes me as a very dangerous thing to do. If someone subsequently reinvents this 'omission' and makes the procedure work, the patent holder has a good chance of getting no royalties.

About - higher yields of hydrazine ?

franklyn - 18-1-2008 at 15:29

Welcome YeOldeImpurities
Very intriguing references , particularly the last about distillation , although
that may pose an explosion risk similar to distillation of H2O2. Iron normally
interferes with hypochlorite processes. By the way, this can't be right,
it's not stoichiometric -
0,3 grams of MnSO4.5H2O to 15 grams of urea, yield 23 grams of hydrazine sulfate

Please post more details if you can, transactions here are in english, few
can read cyrillic. As you see the postings tend to deviate into side issues
unrelated to the main thread. Don't be put off by this, consider starting
another thread of your own.

.

YeOldeImpurities - 23-1-2008 at 12:45

Hi Franklyn, here is an approximate translation from that book: Add concentrated solution of 0.3g of MnSO4.5H2O to 60ml of cooled NaOH solution of density 1.37-1.38. At 0 degrees of celsius add 15g of urea, then cool the solution to -7 degrees. Then gradually add 125ml of NaClO solution cooled to -3 degrees. Do not allow to rise the temperature of the solution over +10 degrees. When NaClO was added, let it stand for 10 minutes. Then heat the solution gradually, 2 degrees per 1 minute in water bath to +63-65 degrees. Then allow to cool to room temperature and add the solution gradually to stirred 140ml of 50% H2SO4. Do not allow to rise the temperature over 40-50 degrees. Then cool to +22-25 degrees and filter out the crystals of hydrazine sulfate and wash them three times with 10 ml of water and dry. Yield 23 grams (70% of the theoretical).

NH2NH2 from KCN, KHSO4, KNO2

franklyn - 6-2-2008 at 18:01

Laboratory Methods of Inorganic Chemistry
Heinrich Biltz, Wilhelm Biltz
http://books.google.com/books?id=1gkNAAAAYAAJ&pg=PA215&a...


From prep 122 on page 158

Hydrazine Sulfate.jpg - 243kB

Mason_Grand_ANNdrews - 4-3-2008 at 03:45

Excuse to write the text into this, it is my second time to write down that. I`ve sitting down, hove some nice ideas and my editor was killed by what you have now 5 minutes to hold. I thkink - it was ""never mind""

I hope it is somewhat for the "balconery" chemistry to get hydrazine.

Prepare two saturated solutions of 4 mol ammonium chloride and 0.5 mol of sodium chloride. Combine the solutions in a beaker in an salt ice bad to minimum 0 degrees centigrade (ammonium) nitrate ice bad is better when you have) that it not will react anytime. A third solution of 6 mol of 25 % ammonium hydroxide is chilled to 0 degrees centigrade and combined with the first mixture in an distiller and put on an distiller by stirring it with an teflon rod.

Step one:
Heat the mix over many hours to the lowest bp of all the liquids
(water 101 degrees centigrade) and put the condenser in an ice bad by connecting the equipment to an disstillation equpment and an simple vacuum pump or an electircal when you have. The distilled liquid is collected in an chilled beaker of ammonium nitrate
ice and connectect to a new eqiupment.

Step 2:
Hold the distillate under cold conditons below 0 degrees centigrade and connect it to an new disstillation equipment with two mol of 25 % HCl in the condenser. The condenser is chilled with an sligh ammonium nitrate ice bad and the yieded liquid is transferd into a new beaker by collecting this
to a new disstillation equipment.

Step 3:
Prepare an ""condenser"" with 2,5 mol of 25 % HCl and connect this to the chilled distiller by step two and over a few hours rise the temperature of the distillate to over 190 degrees centirade and remove the most of the water if you can. The stuff is dryed by placed it to an easy filter paper and hang it over an mix of magnesium sulfate powder and the water is removed over al lot of days.

Soo, i hope this is an real alternative to some hard to get stuff and what you can get from nothing. I`ve to much trunken but i hope it helps.
Money is fare away besides - but i`m an illusian.

By the way, the hydrazinedihydrochloride what the synth. calculated by me is dryed over concentrated sodium hydoxyde or something stuff wath is hycroscopic. I mean it works when the slick is placed into an filter and dryed over concentrated H2SO4 by connecting a vacuum pump to the
flask !

I hope it sometime easy or correct, some hints will help.
It`s very pity that i`ve no lab more that a few years, it more
than an feeling. Maybe someone can this test if it work - i hope.

:P

[Edited on 4-3-2008 by Mason_Grand_ANNdrews]

Formatik - 10-4-2008 at 17:44

Quote:
Originally posted by YeOldeImpurities
Compounds of manganese (sulfate, chloride of manganese, permanganates...) in hypochlorite/urea/hydroxide reaction work better than gelatine. They give 5-10% higher yields of hydrazine than mixtures with gelatine. --- this I remember from book "The Chemistry of Hydrazine" by Audrieth and Ogg.
In russian book Греков,Отрошко: "Гидразинометрия" 1981 (Hydrazinometry by Grekov and Otroshko) is a recipe for making hydrazine sulfate with MnSO4.5H2O instead of gelatine (0,3 grams of MnSO4.5H2O to 15 grams of urea, yield 23 grams of hydrazine sulfate).
And also something else for increasing yields- in book Брикун,Козловский,Никит& #1080;на: "Гидразин и гидроксиламин и их применение в аналитической химии" 1967 (Hydrazine and hydroxylamine nad their application in analytical chemistry by Brikun, Kozlovskiy and Nikitina) is this: best compounds for protection of hydrazine/water solutions against oxidizing by air are oxides of calcium, zinc, aluminium and magnesium but the far superior is sulfur in small amounts. btw there is mentioned a method for producing hydrazine by dry destillation of urea/iron powder at 132-150ºC at atmospheric pressure.


What yield is that of the theory? Raschig in German patent #198307 says hypochlorite solution and ammonia with lime can get as much as 80 percent of the theory, and he himself gets 60 to 70 percent in an example.

Formatik - 25-7-2008 at 05:28

Quote:
Originally posted by Rosco Bodine
GB1073292 Hydrazinium Cyanurate

This is another means of precipitating a slightly soluble hydrazine salt which may be freebased by NaOH .


There are also other hydrazonium salts which might be worth trying. Although the oxalate is soluble, hydrazonium hydrooxalate N2H5HC2O4 is said to result from estimated amounts of oxalic acid and N2H5OH, and these crystals are barely soluble in cold water: 2.02 g per 100 g H2O at 22.5 deg. Hydrazonium subhydrophosphate N2H5H3P2O6 made by neutralizing hypophosphoric acid with N2H5OH against methyl orange and addition of the same amounts of hypophosphoric acid. This salt is even less soluble, 1.5 g per 100 g H2O at room temperature. Compared with the hydrosulfate, the solubilities are for 100 g H2O: 2.794 g at 20 deg, 3.302 at 25 deg., 6.538 at 50 deg., 12.580 at 80 deg., etc. which solubility is also decreased by acids.

Another idea is hydrazonium pyrosulfite (N2H5)2S2O5 which is made by leading so much SO2 into N2H5OH soln. until it turns yellow, this evolves considerable heat. Allowing this to stand in a vaccum or in an SO2 atmosphere, or by precipitating with alcohol causes it to crystallize. The salt also oxidizes easily to sulfate. I bubbled SO2 into a small amount of a weeks old reacted liquor solution of urea to test this, the solution got warm from bubbling and eventually was very barely yellow, and let the solution stand in a closed container for a few hours. At the bottom there was a small amount of glittering, glancing white crystals. Best to try on larger scale, but I would say using the hydrosulfate is more advantageous.

franklyn - 26-7-2008 at 08:51

Syntheses of some N-substituted hydrazines by the anhydrous chloramine process
S R Jain and D Chappella
Proceedings, Indian Academy of Science
Chemical Science Journal , Vol 95 , pp 381 - 389
October 1985

Attachment: N-substituted hydrazines by anhydrous chloramine.pdf (1.9MB)
This file has been downloaded 1126 times


DeAdFX - 9-8-2008 at 08:29

hmmm here is a patent discussing the usage of Ca(OCl)2 as a chlorine source as opposed to NaOCl. I skimmed over the patent a little bit but it certainly does seem interesting. Is their any real benefit in using the ketazine process over the Olin Raschig process?

[Edited on 9-8-2008 by DeAdFX]

Hydrazine from Acetone, Ammonia and Bleach

mbrown3391 - 26-8-2008 at 19:28

1. 2 CH3-C=O-CH3 + 2 NH3 + NaOCl --> CH3-CH3-C=N-N=C-CH3-CH3 + NaCl + 3H2O
2. CH3-CH3-C=N-N=C-CH3-CH3 + 2 H2O --> H2N-NH2 + 2 CH3-C=O-CH3

Has anyone tried this method of preparing Hydrazine?

Sauron - 27-8-2008 at 02:10

Post your referencess for this putative reaction. At present it appears at best incomplete and unlikely.

chemoleo - 27-8-2008 at 03:45

He's referring to the ketazine process, the industrial method of preparing hydrazine.
http://en.wikipedia.org/wiki/Ketazine_process

I seem to remember looking into this, does it perhaps apply high pressure? Somehow I must have concluded at the time that it is not easily possible for the amateur. I don't have my references here, so maybe someone else can help on the details.

Sauron - 27-8-2008 at 04:00

Pretty much what I meant by "incomplete and unlikely"

I have seen acetone cyanohydrin reacted with ammonia, then coupled to the substituted hydrazine, then oxidized to AIBN, the radical initiatyor. But, using that approach then expecting to end up reversing it, keeping the N-N bond while cleaving two C-N bonds?

Sounds like a job for some supercatalyst and harsh conditions.

Of course he could ask Rosco about urea -> hydrazine.

ScienceSquirrel - 27-8-2008 at 04:22

It is definitely a practical approach on an industrial scale.
http://www.atsdr.cdc.gov/toxprofiles/tp100-c4.pdf
However if one is making small amounts of hydrazine in the lab then the classic approach is quite adequate and there are good recipes that if you follow them faithfully will produce a good yield.

kmno4 - 27-8-2008 at 04:43

Oxidation NH3 with NaOCl is standar procedure for making N2H4.
Reaction with acetone has also application for making pure hydrazine salts. But for hydrolysis 30% H2SO4 is using. All these you can find (in russian) in work of Kariakin and Angielov.
Besides, there is HYDRAZINE thread.

NaClO + NH3

tapira1 - 7-9-2008 at 07:53

This works beautiful. The product may be crystallized as the sulfate

kilowatt - 29-9-2008 at 01:07

I did some poking around tonight, and it occurred to me that you could likely crystallize anhydrous hydrazine from any aqueous form significantly exceeding 27% molar (40% w/w) at low temperature. I don't have a full phase diagram, but the eutectic is 27% molar N2H4 and freezes at 193°K. I believe hydrazine hydrate (64% N2H4) begins to freeze at something like -50°C to -60°C. Thus, with dry ice it should be possible to crystallize an amount of anhydrous hydrazine from hydrazine hydrate, leaving a liquid depleted to just over 40% N2H4. The diluted liquid could then be re-distilled. Probably not the most efficient method, but it is interesting anyhow, and perhaps quite suitable for the lab.

Patent literature

chloric1 - 29-9-2008 at 13:24

Well, I read some patents that talk about the ketazine reaction. Although acetone would suffice, the product is water soluble and would be difficult to separate under normal conditions. The patents I am thinking of uses MEK instead because mekazine is insoluble. This can be hydrolysized by heating with strong acid at atmospheric pressure. A reflux setup here would probably be best here. The ketazine can be hydrolysized with plain water. IIRC, it was at 250 C and 10 atm. This sounds bad but a heavy walled stainless tube with a bleed off valve might work. I seem to remmeber they even described the pressure reactor. This would be dangerous but set up your workspace like an explosive bunker and you shoudl be OK.

Just remeber your cheap plastic soda bottle is good to like 8 or 9 atms!!

franklyn - 29-9-2008 at 22:27

@ kilowatt
Interesting idea , but I think if you resort to temperature extremes
there are other methods perhaps better that become available also.

This reference contains data of interest , excerpts are seen below

An Assessment of Hydrazine, Hydrazine Hydrate and
Liquid Ammonia as fuels for Rocket Propulsion

K. A . Cooper & L. A. Wiseman - 1949
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA474005&Locati...

Assessment of Hydrazine  ADA474005.JPG - 179kB

Destroying hydrazine

User - 7-11-2008 at 10:44

Iam planning to throw myself on the hydrazine synthesis (Urea+hypo).
Can anyone tell me how it could destroy hydrazine(hydrate/sulfate) in a worst case scenario.

Grtz user.

Jor - 8-11-2008 at 16:14

First make the solution alkaline, producing free hydrazine, and next add a mild oxidising agent.

Rosco Bodine - 8-11-2008 at 16:22

A little request about attachments, if you will make them about 500 pixels maximum width .....oh never mind ...
what do I know.

Sedit - 26-1-2009 at 18:56

US Patant 7118655 - Direct synthesis of hydrazine through nitrogen fixation by means of two-photon absorptions
------------------------------------------------------------------------------------------------------------------------------------------------

http://www.patentstorm.us/patents/pdfs/patent_id/7118655.htm...

------------------------------------------------------------------------------------------------------------------------------------------------


Question: Since the main part of this relys on the Excition and disassociation or Nitrogen molecule would it be possible for a Transversaly excited Nitrogen laser to replicate these conditions if hydrogen was pumped in at A two times molar ratio?

TE nitrogen lasers rely on a super fast so called blumenthal circuit that can produce pulses on the range of 2.5ns - < 1ns.
There output is in the range of 337.5nm. I feel that even the high power per pulse and frequency may still me in effective though but I was woundering if anyone with more knowlage on this has anyideas that could make this patant in the range of amateur abilitys. N2 TEA laser are not hard to make just finiky but if I can make one anyone can.

Any one have any thoughts on this?

S.C. Wack - 7-2-2009 at 11:45

A couple of articles. Rather than take a chance on an archive, which this board does not like, or make two posts, I'll combine the two.

In JACS 51, 265 (1929), there is the preparation and concentration of hydrazine hydrate solutions by azeotropic removal of water with xylene and toluene. They seem to say that the methods given in Vanino for hydrazine hydrate (pp. 141-2 of the scanned ed.) are lower yielding, and that it is better to make a dilute solution and concentrate it. It would be nice to read the Adams reference that they cite at the beginning, but the only available edition AFAIK of OCR so far (from 1919) does not mention hydrazine.

In JACS 76, 3914 (1954), there are a few experimentals on hydrazine from the mono or dihydrochloride. They used a few methods here.
A sodium methoxide route.
NaOH, BaO, CaO.
And they mention that they had high-yielding experiences using cyclohexylamine, among the high-boiling amines given in US2537791

Attachment: hydrazine.pdf (741kB)
This file has been downloaded 1849 times


not_important - 7-2-2009 at 22:33

Quote:
Originally posted by Sedit
US Patant 7118655 - Direct synthesis of hydrazine through nitrogen fixation by means of two-photon absorptions

Question: Since the main part of this relys on the Excition and disassociation or Nitrogen molecule would it be possible for a Transversaly excited Nitrogen laser to replicate these conditions if hydrogen was pumped in at A two times molar ratio?
...


The N2 is only being excited, not disassociated. Quoting from that patent:

N2H4_from_N2_and_H2.png - 23kB

watson.fawkes - 8-2-2009 at 11:50

Quote:
Originally posted by not_important
The N2 is only being excited, not disassociated. Quoting from that patent:
This is definitely industrial-grade. The cross section for two-photon absorption is rather small at low photon densities, so that means high densities, which means high luminance and everything that entails. Even with high fluences, the rate of absorption is fairly small in terms of transmission percentages, so you want to reuse the beam path as much as possible. Thus a reasonably efficient machine needs to be pretty big for its unit energy consumption to be reasonable.

benzylchloride1 - 6-5-2009 at 21:02

I ran the hydrazine sulfate synthesis described on Sciencemadness that uses 10% NaOCl solution and urea, last year. This synthesis worked well and I obtained 185g of hydrazine sulfate. I am about to run the synthesis on a 1/2 scale in a 3 liter flask with mechanical stirring. The foaming problem seems to be the only issue with this synthesis; the first batch I attempted overflowed the reaction flask. At least it was in a fume hood, so the clean up was fairly easy. This was with the full scale procedure in the 3L RBF. I had the plastic funnel attached to the flask as stated. The second attempt was conducted in a 5 gallon plastic bucket and transferred to the 3L RBF after the foaming stage via a syphon. I obtained a good yield of hydrazine sulfate after neutralization, 185g. I am trying to see if this reaction could be scaled down without severly decreasing the yield. I synthesised 2,4 dinitrophenyl hydrazine, and 3,5-dimethyl pyrazole using some of the hydrazine sulfate. I plan to synthesize some luminol using readily available chemicals, including the hydrazine sulfate produced via this reaction.

Magpie - 7-5-2009 at 14:53

Good work. 185g does seem like a rather large batch. But I suppose that all depends on the intended purpose. Perhaps the originator was using it for pyro or rocketry?

I also want to make luminol and the 2,4 dinitrophenylhydrazine. It seems your wish list is very similar to mine. :)

Was this the synthesis from Mr Anonymous?

benzylchloride1 - 7-5-2009 at 15:53

The synthesis that I conducted was a full scale Mr. Anonynmous synthesis. I ran a 1/2 scale synthesis today. I used a 3 liter 4 neck flask for the synthesis, along with a mechanical stirrer. The 3 liter flask could barely contain the foam. Lots of crystals have formed; I still have to filter and wash the product.

Sedit - 18-6-2009 at 18:25

I hate to bring up an old threed to ask nothing more then a question and not give anything in return but does anyone have information of the method briefly mentioned about the production of hydrazine thru the reduction of nitrates or nitrites using Zinc in a neutral solution?

He sites Ber. 21, 2637 (1888) as a reference but I do not really know how to find this paper thru this information alone.

Mr Anonymous method & ideas 4 improvement

Taoiseach - 11-8-2009 at 04:02

I have performed the hydrazine synthesis according to Mr. anonymous method numerous times now and it worked well. I even scaled the quantities so I could use ordinary battery acid instead of precious conc. H2SO4. The NaOH sol. needs to be more conc. in this case to compensate for the extra H2O which will cause NaCl to precipate while Cl2 is bubbled in. It makes no difference in the end tough coz total amount of water is the same. You just need one more boiling to get everything into solution after it is neutralized with HCl/H2SO4. The hydrazine sulfate will then start to precipate.

I think this is an almost perfect method for OTC hydrazine production. All the chemicals are easy to come by - battery acid, NaOH, TCCS, HCl for Cl2 production and urea which is a cheap fertilizer at least here where I live.

However quite a lot of hydrazine sulfate is lost due to its considerable solubility and the large amounts of H2O required to keep all the reaction products in solution.

I tought about ways to overcome this problem. Obviously what is needed is a less soluble hydrazine salt. Sulfite and oxalate pop to mind as alternative anions but I found no solubility info.

However what I do know is that hydrazine forms insoluble complex salts with certain metals. Both nickel nitrate and sulfate form an almost insoluble precipate upon addition of hydrazine.

There was brief mention in this thread of a "copper hydrazine sulfate". I was unsure if hydrazine sulfate or hydrazine alone was coordinated to the copper in this case, so I tried adding CuSO4 to a dilute solution of hydrazine sulfate. No precipation was observed so I'm inclined to think that the mentioned complex is actually [Cu(N2H4)2]SO4.

The idea is to obtain *all* the hydrazine by precipation as an insoluble complex salt, and then recover it from that salt.

It might be as easy as following Mr. anonymous' instruction up to the point where a dilute hydrazine solution is obtained. This solution must then be neutralized to get rid of CO3(2-) otherwise insoluble metal carbonates will be precipated during the following step. To this neutralized solution is then added a conc. solution of any soluble Ni or Cu salt, and pretty much *all* hydrazine should be precipated due to complexation. I think that the 2 non-binding electrons in N2H4 can bridge two metal ions leading to a polymer-like structure which is insoluble in water. This should work with Ni,Cu,Zn,Co and maybe others as well.

The question now is: How could the hydrazine be recovered from such a coordination compound?

Well here's an idea: Cu(OH)2 decomposes to CuO at 80°C. This should set the coordinated N2H4 free because there is covalent bonding in CuO. Thus destillation of [Cu(N2H4)2]SO4 with NaOH and a small amount of water might to the trick. It needs to be done in a copper vessel (a bent copper pipe might do well) because hydrazine and NaOH eat thru glass easily at elevated temperature.

Obviously this should not be tried with copper salts that have oxidizing anions. Copper sulfate should be fine.

Of course the above mentioned method could also be used to obtain [Ni(N2H4)3](NO3)2 from a neutralized dilute hydrazine solution. After all its a powerful primary :D

[Edited on 11-8-2009 by Taoiseach]

garage chemist - 11-8-2009 at 05:10

Try recovering the hydrazine as ketazine.
Make the solution alkaline, add acetone, stir and wait a while, then extract with toluene.
Reflux the toluene phase with dilute H2SO4 under stirring.
If hydrazine sulphate crystallizes out upon cooling, you have won.

I think you should try the extraction out first with a hydrazine sulphate solution to which 2 mol NaOH have been added, so you don't have any interferences from byproducts from the synthesis.

woelen - 11-8-2009 at 05:37

There is a problem with the suggested method, which uses copper. Copper(II) ions are reduced by hydrazine and this reaction is quick. I once did the experiment of making a copper(II) hydrazine complex in somewhat alkaline solution. The only thing I obtained was a red/brown precipitate, which either is Cu2O, or maybe even metallic copper. The hydrazinium ion does not quickly reduce copper(II) ions. Reduction only occurs at neutral or alkaline pH.

UnintentionalChaos - 11-8-2009 at 06:33

Quite a ways back in this thread, I believe Rosco posted a paper on monohydrazinium cyanurate, which is weakly soluble at best. It also details that a column of Cyanuric acid granules can be used to recover almost all the hydrazine from even dilute solutions.

Taoiseach - 11-8-2009 at 07:48

Sounds good. Isocyanuric acid is a beproduct of chlorine production via TCCS+HCl. Question is: How can hydrazine be recovered from the cyanurate?

If I remember correctly, Na cyanurate is well soluble but the Ca salt is insoluble. Reaction of hydrazine cyanurate with CaCl2 might then give hydrazine hydrochloride plus Ca cyanurate.

Rosco Bodine - 11-8-2009 at 10:42

Quote: Originally posted by Taoiseach  
Sounds good. Question is: How can hydrazine be recovered from the cyanurate?


Sounds good =
http://www.youtube.com/watch?v=leEO7_BV590&fmt=18 First Light

Answer = Add heat :D

More good sound (with added heat ) =
http://www.youtube.com/watch?v=9OJgdlaRzu4&fmt=18
All I Want ....... :D

User - 11-8-2009 at 12:57

wondering, could this be done anywhere within economical reasons.
I know there are by far better methods concerning money still this would be very easy and time saving.

Hydrazine is very easily to destroy by heat right?
So would very little heat be enough to sweat the hydrazine.
Else i can imagine most of it would undergo themolysis/destruction.

uchiacon - 30-11-2009 at 22:00

So I just had a flick through this thread, but I didn't see much discussed on the synthesis of hydrazine hydrate. There were a few suggestions about hydrazine sulfate and NaOH in silver coated glassware, but there wasn't really a proper synth.
I would be using it for the synthesis of sodium azide.

Could anyone please direct me to one?

And I was also just contemplating whether or not I should just buy hydrazine hydrate; it comes in at about $50NZ for 250g of it. $50 NZ is about $40US.

What do you guys think? Is the synth worth the effort?

Taoiseach - 1-12-2009 at 00:18

You dont need silver, copper will do fine.

uchiacon - 1-12-2009 at 00:54

Yes, but even so, it will render my whole distillation kit unsuitable for pretty much anything else, and I only really use it for distillation of nitric acid.

Is it possible to make a weaker hydrazine hydrate solution with just NaOH,water and Hydrazine sulfate and use that for sodium azide? Or wont it work?

How would you coat the whole inside of the glass, would you only need to coat the boiling flask, and why do you need to coat it in the first place? Is hydrazine corrosive to glass?

[Edited on 04-07-09 by uchiacon]

S.C. Wack - 1-12-2009 at 04:02

Quote: Originally posted by uchiacon  
I didn't see much discussed on the synthesis of hydrazine hydrate.


You didn't look very hard.

Myfanwy - 9-1-2010 at 05:55

Yesterday i tried to make hydrazine sulfate of Lye, sulfuric acid and Chlorourea (is that the english name of chlorharnstoff?), without Gelatin to bound the Metallions. I always used distilled water, and cleaned my glassed, but unforntunately no N2H6SO4 crystallised in the cold :(

Formatik - 9-1-2010 at 09:47

Quote: Originally posted by Myfanwy  
Yesterday i tried to make hydrazine sulfate of Lye, sulfuric acid and Chlorourea (is that the english name of chlorharnstoff?),


The English name of the compound in question is N,N'-Dichlorourea (Ger., N.N'-Dichlor-harnstoff), or dichlorourea. There are several N-chlorinated ureas though.

Quote:
without Gelatin to bound the Metallions.


Gelatin is not needed, a variety of other compounds work to bind metal ions (in addition to this thread, also read the patents by Raschig).

Quote:
I always used distilled water, and cleaned my glassed, but unforntunately no N2H6SO4 crystallised in the cold :(


Your explanation is not clear on what you did. Follow closely what has been done and works. Dichlorourea is not without hazard. Remember that if you chlorinate too much, you form extremely dangerous NCl3. If you warm it up in water, NCl3 forms. Not things to take lightly.

Myfanwy - 9-1-2010 at 10:55

No i mean Monochlorourea - CONH2NHCl.
I cant find any information about this compund.

Okay i bubbled 18,3g Cl2 into a solution contaning 15,5g CO(NH2)2.

then i cooled the Sodium hydroxide solution(31g in 60g water) and the monochlorourea solution in an icebath.
after adding both together it gets warm (from 8°C-30°C).
Then i added about 50g 50% H2SO4.

CONH2NHCl + 3NaOH -> N2H5OH + Na2CO3 + NaCl

i think i tooked too much water and cooled not efficiently.


len1 - 9-1-2010 at 14:32

Quote: Originally posted by benzylchloride1  
I ran the hydrazine sulfate synthesis described on Sciencemadness that uses 10% NaOCl solution and urea, last year. This synthesis worked well and I obtained 185g of hydrazine sulfate. I am about to run the synthesis on a 1/2 scale in a 3 liter flask with mechanical stirring. The foaming problem seems to be the only issue with this synthesis; the first batch I attempted overflowed the reaction flask. At least it was in a fume hood, so the clean up was fairly easy. This was with the full scale procedure in the 3L RBF. I had the plastic funnel attached to the flask as stated. The second attempt was conducted in a 5 gallon plastic bucket and transferred to the 3L RBF after the foaming stage via a syphon. I obtained a good yield of hydrazine sulfate after neutralization, 185g. I am trying to see if this reaction could be scaled down without severly decreasing the yield. I synthesised 2,4 dinitrophenyl hydrazine, and 3,5-dimethyl pyrazole using some of the hydrazine sulfate. I plan to synthesize some luminol using readily available chemicals, including the hydrazine sulfate produced via this reaction.


The trouble with that synthesis, is that despite a great deal of detail its rather imprecise in its key point. For instance the volume of bleach is measured with great precision 1892ml, but then the bleach strength is quoted at 10%. Just a 1% change to 11% bleach strength alters the water content by 180ml, which makes a mockery not only of measuring the volume to that precision, but also the subsequent attempts to dissolve the NaOH in bleach, and the urea, and gelatine in a barely adequate amount of water.

There is the possibility that what seems to be a round figure of 10% in reality is accurately measured. That is unlikely, as the author does not seem to have performed bleach titrations. For instance he states that 10% bleach solutions decompose within a few weeks, to a couple of months. I have done bleach titrations, and a solution 11.5% strong, is still 8.2% even after 3 months non air-conditioned storage in temperatures which have exceeded 40 degrees for long periods of time.

Formatik - 9-1-2010 at 18:45

I stand corrected, it was monochlorourea. I didn't have time to check and verify earlier today. Dichlorourea had received recent attention also.

Beilstein Chlorharnstoff reference is 3 [I] page 35, [II] page 61. Supplements of the third volume of the 4.Auflage.

[Edited on 10-1-2010 by Formatik]

DJF90 - 9-1-2010 at 18:57

Formatik: In Chattaway's paper on dichlorourea, he states that diurea precipitates on hydrolysis with excess ammonia. My question to you (if you know the answer) is what yield of diurea is obtained? Its got me interested...

franklyn - 18-1-2010 at 10:33

This is more in the realm of my wishful thinking, but could it really be true ?

(NH4)2SO4 + MnO2 => MnSO4•2H2O + H2NNH2

Ammonium Sulfate and Manganese Dioxide mixed in a 1 : 1 molar ratio , sealed in
a bottle that is heated in a pot of boiling brine would reform into a quantitative yield
of anhydrous Hydrazine with a precipitate of hydrated Manganese Sulfate , MnSO4•2H2O
or perhaps even a complexed adduct of both.

Some facts :

- • - Ammonium Sulfate (NH4)2SO4 decomposes at 100 °C ,
liberating Ammonia to form Ammonium Bisulfate , NH4HSO4.

- • - Ammonium Bisulfate , NH4HSO4 is acidic; pH 5.5.

- • - Manganese( IV ) Oxide , MnO2 , heated with sulfuric acid , yields Manganese( II ) Sulfate,
evolving oxygen: MnO2 + H2SO4 => MnSO4 + H2O + ½ O2

- • - pH of Manganese Sulfate MnSO4 is in the range of 3 - 3.7 , 5 - 7 for MnSO4•H2O

- • - Ammonium Bisulfate , NH4HSO4 melts on heating to 147 °C , decomposing at 280 °C

- • - Hydrazine boils at 114 °C up to 121 ºC for the azeotropic hydrate

- • - Manganese Sulfate , MnSO4 loses all water of hydration @ 400-500 ºC
it's melting Point is 700 ºC

- • - Manganese Dioxide decomposes at 535 ºC

- • - In the presence of dilute acids ( acidic salt in this case ) MnO2 is readily
attacked by strong reducing agents.

A potential problem is that such hydrazine as may form , may be oxidized
by unreacted MnO2 markedly reducing yield.


There is some precedence for this idea with copper sulfate and ammonia.

On the action of dry ammonia gas on sulfates
Chemical News & Journall of Physical Science Vol 66 , Page 223 ( 1892 ) -
http://books.google.com/books/download/Chemical_news_and_jou...
Excerpt attached below

.

Chemical News Vol 66 Pg 223.gif - 56kB

Taoiseach - 19-1-2010 at 12:23

Interesting idea. I once read somewhere that tetramminecopper(II)nitrate, [Cu(NH3)4](NO3)2 produces small amounts of hydrazine upon decomposition. This would at least support the idea of sulphate/dioxide being able to oxidize NH3 to hydrazine without decomposing it at once.

Its all about getting two nitrogen atoms to bond to each other. That paves the way to azides, tetrazoles and other nitrogen-rich energetics. Its the only reason why hydrazine is interesting to us - because it has the N-N bond, and very few reactions (especially inorganic ones!) form this bond.

Myfanwy - 29-1-2010 at 10:17

would be great, but i think its impossible, because metallions will cause decomposition of N2H4, especially in the heat and the reaction between ammonium sulfate and manganese dioxide needs heat.

why not try it in a test tube. i think ammonia will given off.

Taoiseach - 30-1-2010 at 12:25

Nope manganese(II)sulfate is a known catalyst for the formation of hydrazine. It has been mentioned in this thread. I couldn't believe it myself at first but I actually found a reference for this. If anyone is interested and I look hard enough around my chaotic collection of chemistry files I might find it again :)

[Edited on 30-1-2010 by Taoiseach]

len1 - 31-1-2010 at 22:47

I have a uni practical chemistry instr which also requires MnSO4.5H2O added to urea/OCl-, and no gelatine. This is bizzare as transition ions are meant to catalyse the decomposition. And even if Mn2+ works the other way, I cant see what it can do about the Cu2+ already in solution.

And heres the final punchline - I tried the synthesis with Mn2+ and no gelatine - 0 yield!

Myfanwy - 6-2-2010 at 15:46

Is it dangerous to distill hydrazine(hydrate)?
Im afraid, that it could explode :(

I would make it by hydrazine sulfate and an excess of sodium hydroxide.

anyway how to store hydrazine.
its very unstable on contact with oxygen in the atmosphere.

Could it decompose after some time?
And how corrosive is N2H4?

Myfanwy - 6-2-2010 at 16:30

oh man why so kind?


Myfanwy - 6-2-2010 at 16:31

i wouldnt have asked, if i had any books about hydrazine.

densest - 6-2-2010 at 22:02

Quote: Originally posted by Myfanwy  
i wouldnt have asked, if i had any books about hydrazine.


Several books in electronic, downloadable form have either been posted to the forum or good links to them have been posted. Most of them are old (out of copyright) but they do have information about distilling hydrazine (not a good idea), how to store it (as a compound), etc., etc., etc. Other useful information is earlier in this thread and elsewhere on this site, accessible via the search feature.

franklyn - 7-2-2010 at 12:07

@ Myfanwy

You posted 3 times in 15 minutes. The forum is
similar to a community bulletin board in that it
may take several days to receive a response.
You will not experience instant gratification here.

- Asking about things so thoroughly covered
already , discloses you to be someone who cannot
so much as do a cursory search on the topic.

- If you have an interest in this subject go to the
first page of this thread and slowly look through
it to understand what you can expect to have to
do.

- You have a choice between the " Anonymous "
method or the traditional " Raschig " procedure.

- The sulfate salt is very safe compared to the
freebase which does fume.
_____________________

- Hydrazine cannot be made with (NH4)2SO4 / NaOH

You need to understand the difference between
research into unknown but plausible investigation
and elaboration of tried and tested preparations.




[Edited on 8-2-2010 by franklyn]

franklyn - 7-2-2010 at 19:43

From my post above _
" This is more in the realm of my wishful thinking, but could it really be true ?
(NH4)2SO4 + MnO2 => MnSO4•2H2O + H2NNH2

More than just partial oxidation of ammonia is necessary. I found this post
http://www.sciencemadness.org/talk/viewthread.php?tid=6777#p...
which describes that hydrogen and nitrogen result as can be expected , since no
mechanism exists to specifically form an , N - N , bond. The usual way this occurs is
with Chloramine / Ammonia metathesis thus H2NCl + NH3 => N2H4
HCl is neutralized by the hydroxyl base remain of the hypochlorite reagent.
Chloramine is unstable even cold so the prospect of a melt with hypochlorite
2 (NH4)2SO4 + Ca(ClO)2 + CaO => 2 CaSO4•2H2O + 2 N2H4•HCl
is not even possible. The essential reaction does occur thus :
(NH4)2SO4 + Ca(ClO)2 -> CaSO4•2H2O + 2 H2NCl
Suggesting a two stage procedure feeding Chloramine output into liquid ammonia.
Some prior research _
http://www.dtic.mil/srch/doc?collection=t3&id=ADA071194

.

Myfanwy - 9-2-2010 at 13:24

can you chlorinate urea directly with trichloroisocyanuric acid?
better then leading a stream of chlorine in it.
then just filter the (iso)cyanuric acid away.

(OCN-Cl)3 + 3H2O -> (OCN-H)3 + 3HOCl
3HOCl + 3CO(NH2)2 -> 3CONHClNH2 + 3H2O
-
(OCN-Cl)3 + 3CO(NH2)2 -> (OCN-H)3 + 3CONHClNH2

wouldnt that work?

did anyone tried that?

-----

guys i think this is the best method!okay i added about 18g Urea to 30g distilled water and dissolved some gelatin in it.

then i dissolved 31g NaOH in 30g dWater.

i added outside 20g TCCA in the urea solution. it foams up releasing very NASTY chloroamines. i hate this smell. really. i thought i must vomit.
then i filtered the solution away from the white solid.
no NCl3 was produced.

i dropped it in the Lye with 1 drop in every 2 seconds.
it foamed up producing nitrogen.
there was no chloroamine smell.

when i added 1 drop of concentrated H2SO4 it nearly exploded:o:o.
The reaction was somewhat exotherm and dangerous.
also there were lots of white hydrazine fumes. i had an clear fuming liquid. the smell of hydrazine was comparable with ammonia, but not that irritating. it was a little bit sweetish.

i dilute the H2SO4 to 50% and even with that concentration it nearly explodes.
i added 100ml water to the hydrazine solution and dropped the H2SO4 in it. now it wasnt that dangerous at all.
it gets really hot and i standed in a little N2H4 cloud.
i hold on the breath (i done the whole experiment outside), because i read, that N2H4 is very corrosive to the lungs.
after the experiment i had a little pain in the lung, but now its over.

i think i added to much water. hopefully N2H6SO4 will crystallizes out.
The solution is now in the ice bath...

[Edited on 10-2-2010 by Myfanwy]

----

haha guys i love you. the best experiment i done in the whole month.
when i wrote the first part of the edit, the solution was closed in a glass, standing in an icebath.
i looked at it,but there was no crystalls.

when i opened the glass, the whole liquid became a colorless mass =D

i will now filter the crystalls and wash them with ice cold water.
i think recrystallization isnt necessary.

sorry for bad english at all.
here are some pics.

[Edited on 10-2-2010 by Myfanwy]

[Edited on 10-2-2010 by Myfanwy]

Myfanwy - 10-2-2010 at 12:27

okay here they are.
had to resize them..

max1.jpg - 44kB
max2.jpg - 39kB
max3.jpg - 26kB
max4.jpg - 35kB

[Edited on 2-10-2010 by Polverone]

Polverone - 10-2-2010 at 12:56

This is an interesting approach! In many places TCCA is more available, and cheaper per mol of active chlorine, than strong hypochlorite solutions.

Much to my chagrin, and amusement, in reviewing I see that I had the idea of TCCA oxidation of urea back in 2002 but neglected to ever do anything with the idea. Chris the Great tried the procedure on a small scale in 2005, with apparent success, but had difficulty scaling it up.

TCCA does not dissolve easily in neutral aqueous solution. I am wondering if the TCCA completely dissolved/reacted in the urea solution, despite the urea excess in your experiment.

I would be very interested if you can calculate yield of hydrazine from your experiment and validate the purity of the sulfate.

Taoiseach - 10-2-2010 at 13:08

I really enjoy your experimental reports Myfanwy, its always something interesting :)

>when i added 1 drop of concentrated H2SO4 it nearly exploded:o:o.
>The reaction was somewhat exotherm and dangerous.
>also there were lots of white hydrazine fumes. i had an clear fuming liquid. the smell of hydrazine was comparable with ammonia, but not that irritating.
>it was a little bit sweetish.

Well you get the same result when you drop conc. H2SO4 into conc. NH3 solution. Given the chemical relation between NH3 and H2N-NH2 this comes as no suprise. I find the smell of hydrazine very hard to describe, its a tad like NH3 but less irritating and a bit like rotten fish IMHO.

>i hold on the breath (i done the whole experiment outside), because i
>read, that N2H4 is very corrosive to the lungs.
>after the experiment i had a little pain in the lung, but now its over.

Be more careful with this stuff or you could suffer serious health problems! Hydrazine is a known carcinogen.

The stuff on your pictures however doesn't look like hydrazine sulfate to me. HS forms chunky crystals, but on the pics it looks like needle shaped crystals. You should put a little bit into a test tube and heat it. If its HS it should evaporate leaving no solid residue. When I tested my HS this way I also smelled SO2 and the solid turned yellow for a few seconds (elementary sulfur?) until it all evaporated.

Myfanwy - 10-2-2010 at 13:51

yes. now the product is drying at 50°C.
i will test the purity tomorrow and scale the product.

but im sure this is hydrazine sulfate, because its bad soluble in cold water.

i tried 10 minutes ago the reaction between silver(I)-nitrate, because hydrazinium salts are good reducing agents.
i thought, that it would create an silver mirror.
and it does :P

mabe i will try tomorrow, if the N2H6SO4 will produce with NaOH N2H4 and burn it.




max1.jpg - 38kB

franklyn - 10-2-2010 at 14:10

b]@ Myfanwy

I compliment you on your success.

Must avoid breathing hydrazine fumes
you're doing so if you can smell it.
Stand up wind outside or have a fan
provide draft. Another solution might
be to wear a gas mask.

http://www.sciencemadness.org/talk/viewthread.php?tid=2374#p...
http://www.sciencemadness.org/talk/viewthread.php?tid=2374&a...
http://www.sciencemadness.org/talk/viewthread.php?tid=6375#p...

There are old chemists and bold chemists
but there are no old bold chemists.

.

len2 - 11-2-2010 at 01:37

Quote:


guys i think this is the best method!okay i added about 18g Urea to 30g distilled water and dissolved some gelatin in it.

then i dissolved 31g NaOH in 30g dWater.

i added outside 20g TCCA in the urea solution. it foams up releasing very NASTY chloroamines. i hate this smell. really. i thought i must vomit.
then i filtered the solution away from the white solid.
no NCl3 was produced.

i dropped it in the Lye with 1 drop in every 2 seconds.
it foamed up producing nitrogen.
there was no chloroamine smell.

when i added 1 drop of concentrated H2SO4 it nearly exploded:o:o.
The reaction was somewhat exotherm and dangerous.
also there were lots of white hydrazine fumes. i had an clear fuming liquid. the smell of hydrazine was comparable with ammonia, but not that irritating. it was a little bit sweetish.

i dilute the H2SO4 to 50% and even with that concentration it nearly explodes.
i added 100ml water to the hydrazine solution and dropped the H2SO4 in it. now it wasnt that dangerous at all.
it gets really hot and i standed in a little N2H4 cloud.
i hold on the breath (i done the whole experiment outside), because i read, that N2H4 is very corrosive to the lungs.
after the experiment i had a little pain in the lung, but now its over.

i think i added to much water. hopefully N2H6SO4 will crystallizes out.
The solution is now in the ice bath...





The first step in the oxidation of urea by TCCA would be the formation of hypochlorite which then oxidizes the urea.

In the above I can not see how this can happen to any significant degree since to get TCCA to release chlorine you must use acidic conditions. That is indeed how its release in the pool for which it is intended is governed.

Moreover if you oxidize urea in acidic conditions there will be CO2 generated with the hydrazine as you can see elementarily from the equation, the reaction is heavily exothermic, and you get thermal runaway (this is not a guess) - this is why the degradation of urea is done in basic solution. If this does not occur in the first stage of the above process it is only due to the paucity of Cl2 and hypochlorite available in solution. Addition of base afterwards will only reduce the amount of Cl2 already present.

I therefore doubt the above method, both in terms of yield and the purity of product - its mostly cyanuric acid which is little soluble in water - and another reason why the reaction can not be done this way.

[Edited on 11-2-2010 by len2]

franklyn - 11-2-2010 at 05:40

@ len2

What can be expected is not always what you get.
No reaction would not explain the following report by Myfanwy
" I added outside 20g TCCA in the urea solution. it foams up releasing very NASTY chloroamines "

" I dilute the H2SO4 to 50% and even with that concentration it nearly explodes "
Clearly there must be Na2SO4 forming and also Cyanuric , which explains the large volume of yield.

I cannot think of any competing reaction that can account for this :
" I tried 10 minutes ago the reaction between silver(I)-nitrate,
I thought, that it would create an silver mirror , and it does "


- len2
" I therefore doubt the above method, both in terms of yield and the purity of product -
its mostly cyanuric acid which is little soluble in water." -


Hydroxide will salt out Na2SO4 and Sodium Cyanurate leaving hydrazine hydrate solution
which can be further tested. Lets wait and see.
" I will try tomorrow, if the N2H6SO4 will produce with NaOH N2H4 and burn it "

.

Myfanwy - 11-2-2010 at 07:16

i have 27g. This is a yield of more than 80%.
cant be true...
may i should recrystallize it?

i heated an solution with this stuff with a concentrated lye and there was hydrazine produced.
but it didnt burn, i think because there was to much water vapors. but the hydrazine smell was detected.

are there some specific tests for N2H6SO4.
hydrazine can be released with a base.
and with BaCl2 BaSO4 crystallizes out.

are there some more?



max1.jpg - 40kBma2.jpg - 38kBmax3.jpg - 31kB

Taoiseach - 11-2-2010 at 08:03

>are there some more?

If you had read my post above you wouldn't ask: HEAT IT.
If it leaves anything solid, its not hydrazine sulfate (or at least not pure HS)! HS decomposes producing gaseous products only. I cant think of any other product that could form in this reaction which also forms gasses only.

[Edited on 11-2-2010 by Taoiseach]

Nicodem - 11-2-2010 at 09:10

Quote: Originally posted by Myfanwy  

are there some specific tests for N2H6SO4.
hydrazine can be released with a base.
and with BaCl2 BaSO4 crystallizes out.

are there some more?

Perhaps the most obvious test, taking a melting point?

Quote: Originally posted by len2  
The first step in the oxidation of urea by TCCA would be the formation of hypochlorite which then oxidizes the urea.

In the above I can not see how this can happen to any significant degree since to get TCCA to release chlorine you must use acidic conditions. That is indeed how its release in the pool for which it is intended is governed.

TCCA is one of the most electrophilic chloroimides and it easily N-chlorinates practically any amide (sulfamides included) with a free NH position (for literature examples see: US3850920; CA 116: 128875; or Synlett, 2005, 223-226). The yield is usually quantitative if using acetone or similar solvents because cyanuric acid is nearly insoluble and its precipitation forwards the otherwise reversible reaction to full conversion. I think there is no reason to believe that ureas are an exception and that monochlorourea would not form by chlorination of urea with TCCA. In water as solvent the yield might by slightly lower than using a solvent where TCCA is soluble and cyanuric acid isn't (it is hard for all TCCA to react when its solubility in water is nearly as low as that of cyanuric acid).
Also there is no need for acidic media for TCCA to hydrolyse to HClO. The hydrolysis equilibria constant for TCCA is 6.7×10^(-4) mol/L in water (see Kirk-Othmer), which is indeed very low, but not prohibitively low if HClO is getting consumed while forming. Nevertheless there is no need to involve HClO in the reaction mechanism (particularly when there is no need to do so). TCCA is just as electrophilic as HClO even if in neutral media and probably even more so in water as solvent.

Quote:
Moreover if you oxidize urea in acidic conditions there will be CO2 generated with the hydrazine as you can see elementarily from the equation, the reaction is heavily exothermic, and you get thermal runaway (this is not a guess) - this is why the degradation of urea is done in basic solution. If this does not occur in the first stage of the above process it is only due to the paucity of Cl2 and hypochlorite available in solution. Addition of base afterwards will only reduce the amount of Cl2 already present.

I'm not familiar with the urea->hydrazine process, but are you sure that monochlorourea (or aqueous urea in the presence of Cl2) decomposes in acidic media? There is an example in the literature where monochlorourea is recrystallized from acetic acid. The preparation of aqueous solution of monochlorourea in Org. Synth. uses CaCO3 to avoid basic conditions (as HCl scavenger), but then the reagent is used in slightly acidic conditions as a source of HClO (used for making a chlorohydrin). It does not mention any problem with decomposition. I'm also having a hard time imagining any mechanism for the formation of hydrazine from monochlorourea that would not involve bases. With bases there are at least two available mechanisms, either Favorsky-like or Hofmann-like rearrangements (actually their "aza" variants). I find the aza-Favorsky mechanism more likely as it would not involve any heating. In any such case the presence of a base is needed even though already just slightly basic conditions should be enough given the relatively high NH acidity of ureas (possibly even Na2CO3 might be enough).

Edit: Forgot to mention that TCCA does not release chlorine unless reduced, for example by HCl, chlorides, sulfites, nitrites, alcohols or some other organics, etc. It does not matter if the medium is acidic provided that the acid is nonreducing. It will utmost partially hydrolyse to HClO as mentioned above. You can even make a solution of TCCA in conc. H2SO4 and it will not decompose. A pretty nasty solution and a source of extremely electrophilic chlorine(I) species (this combination can perchlorinate even nitrobenzenes!). Just don't put a finger in it. :D

[Edited on 11/2/2010 by Nicodem]

Myfanwy - 11-2-2010 at 09:15

taoisearch i read your post, but my burner is empty so i cant do it at this time.
taking a melting point i cant do ,too.

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