Hydrazine

Speak of the devil , ........
and then look above

Ammonia and bleach give chloramine (Cl-NH₂, Tim.

Rosco, why don't you just tell everybody else who Mr. Anonymous is?

Somewhat related to the topic: how long will stored hydrazoic acid last before decomposition?

sparky (~_~)

Quote:

Originally posted by sparkgap Rosco, why don't you just tell everybody else who Mr. Anonymous is?

Mr. Anonymous and Rosco Bodine are aliases . These aliases conceal
the true identity of Rosco P. Coaltrain , sheriff of Hazzard County ,
to keep him out of trouble with Boss Hogg , chief of animal farmland security

The container of hydrazoic acid I saw in our lab was being kept at quite cool temperatures, so I guess its volatility and rate of decomposition should be reduced. Still, I'm thankful I've never needed to use it in any of my experiments.

I thought as much about the toxicity. IIRC, azide ion is a good inhibitor of the ETC so crucially needed in respiration.

Thanks, Mr. Anonymous.

sparky (^_^)

Just a writeup

12 grams of sodium hydroxide was dissolved in 35 ml distilled water and added with the aid of a sepretory funnel (tight fitting ground glass) with magnetic stirring to 20 grams of hydrazine sulfate. The additions were done over the course of and hour and a half during which very slight heating was observed.

At no point did everything become liquid but I assumed the heavy precipitate at the bottom was sodium sulfate that had been produced. This mixture as then set up to distill. The apparatus is in the attached picture. I distilled into a sepretory funnel so that I could take off the distillate at different times. The gasses were simply lead away and bubbled into water.

The distillate started to come over when the water bath was at about 130 C and the still head only rose to 100 C so it was mostly water coming over. The bath temperature continued to climb until it held at 152 C and the stillhead continued to hold at 100 C. A portion of the liquid distilling was removed and a few drops were added to a test tube of bromine water, immediately removing the color. So a positive test for reducing character. A large portion of the hydrazine came over in this region, too much water, too afraid of distilling anything less then the azeotrope (hydrazine hydrate) at 120 C. It took a lone time to remove the water, the amount of azeotrope expected to come over was only 6.75 ml and therefore it came as no suprise when after 17 ml of water came over I only had a short break around the point of the azeotrope before there was a temperature drop and liquid stopped distiling. Additionally the flask was bumping quite a bit and I didn't want to press it considering it was hydrazine.

I know there are better ways to get the hydrate but this way has always bekoned to me, now I only have 480 g hydrazine sulfate left....

BTW, does anyone have any details on the preparation of anhydrous hydrazine by distilling it from hydrazine borate? Expecially the preparation of said compound?

[Edited on 5/6/2005 by BromicAcid]

Hmm, it's a tricky one since things are so interlinked - the production of Hydrazine and azide - particularly when a single post contains descriptions of both (something I cant split easily without disrupting the flow).
If there's a specific post that I overlooked and doesn't belong here, let me know.

Suggestions welcome. I would only want to perfect the layout of such a high-level discussion

I will remove this post later, once/if I got suggestions (U2U pls).

PS oh yeah rosco you are damn right

[Edited on 7-5-2005 by chemoleo]

Yes , the scale and concentration and
what you are trying to do within a given volume influences your choice of method ,
and the thermal considerations are no small factor . I tend to work with what
some would consider huge batches , but
having an industrial background has distorted my perspective towards molar
instead of millimolar quantities , unless caution about some stabilty issue or toxicity finds me working with "mini" scale . I dislike working with very small quantities when doing reactions about which I have confidence , seeing the same amount of labor and steps required can be scaled up greatly and then the " stash " of the desired material
is increased , having made the effort more
worthwhile . To me a modest batch of NaN3 is 75 grams or more from a liter of
methanolic Hydrazine Extract

OK, all right.

Could there be some unknown hazards with the chlorourea process? The worst- case scenario would be the formation of nitrogen trichloride.
Interestingly, NaOCl + urea also yields large amounts of NCl3, but only under special conditions (NaOCl added to a mixture of urea and sulfuric acid- here, chlorine is first produced from the NaOCl and acid). There was a thread about this somewhere...

I'll try the chlorination of urea with very small amounts first and look if it's safe.

@ Mongo Blongo: Do you use DanKlorix? It is 2,8% NaOCl, it is written on the bottle (under "Anwendungen", it's rather hidden).
I was not able to get any HS with 2,8% NaOCl.

Anyway, I'll never use hypochlorite again, because today I tried the chlorourea process and IT WORKED!!!

Here's what I did:

In a 3-neck 250ml rbf equipped with a gas inlet tube whose tip had been pulled out into a "pipette tip" (the other two necks were simply left open), I put 20,5g urea.
In a beaker, I dissolved 0,2g gelatin (this is still necessary!) in 45ml warm distilled water.
This solution was added to the urea and it was stirred until the urea had dissolved.
A gas generator was set up (100ml rbf and pressure- equalized dropping funnel with gas outlet at the side) and charged with 10g TCCA (made into a slurry with 10ml water) and 34ml 25% HCl.
The HCl was slowly added to the TCCA, the chlorine bubbled through the urea/gelatin. The urea solution and TCCA were swirled from time to time to ensure complete reaction. The chlorine bubbles reacted completely, no chlorine smell was noticed.
When all the HCl was added, the TCCA/HCl sludge was heated to nearly the boiling point to expel all the residual chlorine.

In a 500ml rbf, 16g NaOH were dissolved in 40ml distilled water. To the resulting hot solution the chlorourea solution was added immediately and all at once. It was swirled to ensure complete mixing.
The solution went dark orange and white foam was produced, the solution approximately doubled its volume.
It looked EXACTLY like a normal batch of HS with hypochlorite!
It was slowly heated, the foam slowly subsided and the color became lighter.
When it was almost boiling, it was nearly colorless. It was left to cool.

While stirring with a magnetic stirrer, 60ml 25% HCl (a bit more than needed to neutralise the used NaOH) were slowly dripped in, CO2 was being produced, and the hydrazine fumes+HCl gas formed a white fog in the rbf.
18ml of conc. H2SO4 were diluted with 20ml water and slowly dripped into the well stirred mix. After about two thirds were added, a precipitate suddenly occured.
The rest of the H2SO4 was added more slowly in order to produce larger crystals.

It was left to cool to room temperature, then it was cooled to 0°C in an ice bath. 100ml of the supernanant liquid were set aside to wash residual crystals out of the rbf.
It was filtered through a coffee filter and washed with a small amount of ice- cold distilled water and then with some ethanol.

It's drying at the moment. The theoretical yield (100%) would be 13g, but some HS stays in solution of course.
Tomorrow I'll weigh it. It looks like about 8 grams.

I can think of several improvements to this reaction:

The most important thing is to make sure that one uses exactly the right amount of chlorine. The production from TCCA+HCl is very cheap, but this reaction doesn't go to completion (that's why I used a bit more than the theoretical amount). Also, the commercially available material is only 92% TCCA. I will have to find out the amount of TCCA that produces exactly 0,1 mol of chlorine. I'll either have to collect the gas over water (via pneumatic bowl) or use it in a reaction where the product can be titrated.

Another important thing would be to use more concentrated solutions. Especially the NaOH can surely be used in a 50% solution (saturated). The urea can also be used as a more concentrated solution (the patent actually uses a slurry, but this would hinder the reaction since the mix is not homogenous, so I'll use a saturated solution instead).

When a high enough concentration of reactants can be reached, it might become economic to distill off the hydrazine as the hydrate instead of precipitating it.

Maybe I should, after optimization, publicate the entire process as "Mr. Anonymous 2"?

[Edited on 18-5-2005 by garage chemist]

Well done Garage Chemist!
I'd be really interested what yield you got, having done the Raschig process I know what a pain it is, and what large volumes have to be used!
I suppose one of the great advantages is the fact that small volumes are used from the beginning, avoiding this concentration step that is necessary with the Raschig process.

In other words, the hydrazine is already quite concentrated. I wonder if even smaller volumes for dissolution could be used. (edit:seems you mentioned this in an edit)

Oh, and why do you first use HCl to neutralise the NaOH, then H2SO4? Isn't it possible you have losses due to the more soluble hydrazine chloride? So why not using *only*H2SO4?


PS I hope you did a quick testrun before doing such large volumes - weren't you afraid of NCl3?

Why also do you want to use exactly the right amount of chlorine? It might help to put up the reaction equation btw

Great work anyway!


[Edited on 19-5-2005 by chemoleo]

Just a couple of thoughts that may be useful , if the reaction mechanism is what I suspect it may be , and the monochlorourea / dichlorourea are unstable not well defined compounds chemically , but inclusion compounds , which are " sponges " for adsorbed chlorine . The Schestakow type reaction
is not adversely affected by excess NaOH ,
and the quantities I arrived at were for sufficiency and economy for the reaction using the sodium hypochlorite already formed in the usual way . But for the monochlorourea or polychlorinated urea
which may occur , it may be better to use a bit more total NaOH so that any excess chlorine is converted to hypochlorite . It is important to keep the ratio of urea to hypochlorite correct so there is no substantial excess of hypochlorite , and this should translate for the ratio of total chlorine to urea also . But it hurts nothing to have excess NaOH , it just requires more HCl for the intial neutralization . These ratios may vary some from what is best for the direct hypochlorite method may not be directly applicable to the monochlorourea method , but I suspect the ratios will be close enough that interchangeability is a valid starting point . Anyway , please do
try using the weaker bleach with NaOH ,
and then you need not worry about overchlorinating the urea , because you can have the unreacted urea present in an amount which will react with the hypochlorite already present in the bleach . This will avoid any danger for overchlorinating the urea , and at the same time will give a more concentrated reaction mixture .

When the foam is subsiding and you see
that happy bright orange color ......

Whew , I think it's gonna be alright
Yeah, the worst is over now .....

My reaction flask is shinin'
like a red rubber ball

All genius is seasoned with a sprinkle of madness ......

and for some of us , there is more of a sprinkle than for others

[Edited on 19-5-2005 by Rosco Bodine]

Attachment: redrubberball.mid (38kB)
This file has been downloaded 1438 times

Chlorine Simple Method

Hydrazine Cyanurate

Your message and my edit just passed each other in flight through cyberspace .

I understand exactly what you are saying and you are correct that with that low a concentration of bleach , there is likely no gain and probably a loss for trying to combine the methods .

Europeans need to riot in the streets demanding that their bleach be watered down no longer , that you are just not going to take it any more , paying top Euro for chlorox that has been " stepped on " by the middle man

But for those of us who can get 10% bleach at the grocery store , the possibility
of in effect doubling the concentration of the reaction mixture for the usual process
does have a certain appeal .

The final yield of HS from the chlorourea process was 9.62 grams. My guess was high as the crystals must have contained more water than I had guessed, but still a good quantity.

Here are a few pictures. The pan on the right contains high grade HS from a known source. The pan on the left is the material from chlorourea process.

The spectra in red is the material from the chlorourea process and the one in green is from my known source which is at least tech grade or better. Unfortunately my libraries did not contain a commercial spectra of HS so we all will have to compare by eye. The peaks under 3200 and 3400 are probably from residual H2SO4. I need to recrystalize and run it again but it looks like a good match from my experience.

Sorry about the multiple posts but I can't seem to figure out how to post more than one pic at a time with my old Mac.

Here are the starting materials for my HS from chlorourea experiments.

Where I got my known good hydrazine sulfate from.

The modification of the chlorourea process for semicarbazide as the end product should also be interesting .

There has been mention of the possibility
of using semicarbazide as a precursor to azides , but I know of no references nor details concerning the reaction .

Earlier in the thread there was mention about the possible danger of nitrogen trichloride being a byproduct with the chlorourea process . It was mentioned in the pdf regarding the use of TCCA as an oxidant on page 2 , that it is possible for nitrogen trichloride to form in strongly acidic solutions of TCCA , so this may need to be considered when the source of chlorine is TCCA . Whether the formation of nitrogen trichloride is temperature dependant or not I do not know for certain . It would probably be a hazard avoided simply by conducting the chlorine generation at warmer temperatures at which any NCl3 formation or accumulation would not be favored , and evolution of Cl2 would be
assured . Curiously this is likely one of those reactions where heating is the essential guarantor of safety , and cooling would not be a good idea for the TCCA based " chlorine generator "

A parallel is likely true for the chlorourea formation . Keeping the temperature slightly warm , maybe 25 C for example ,
would be safer than say using an ice-salt
cooling for the chlorination of the urea .

[Edited on 14-6-2005 by Rosco Bodine]

hydrazine synthesis continued

Anyone is welcome to test variants and chart the results of what improvements are
* proven * by alternate hypochlorites ,
mixtures of hypochlorites , and modified conditions for the reaction which * prove *
useful . But since it is known for certain that the urea process is sensitive to small variables , then there is no basis for any conclusions about what is better in the way of changes to the known process ,
before actually testing and retesting the modification to make certain it has validity . Knowing how sensitive the reaction is to small variables is exactly why I performed a half dozen experiments for confirmation , before having the boldness to declare that use
of hydrochloric acid for the initial neutralization , and then following that with sulfuric acid for securing precipitation of the sulfate , was a * superior * method . You see there is a huge *inertia* associated with textbook methods which have been in practice for a hundred years , and any maverick suggesting changes should be sure they aren't calling a press conference in Utah to report their success at cold fusion using a method nobody else on earth can reproduce

[Edited on 17-6-2005 by Rosco Bodine]

@ hannibal

Hydrazine From Urea

Hydrazine And Its Derivatives - 1st Edition

Analysis

a little help...?

just interested in ending up with hydrazine hydrate here, not a question about converting it to the sulfate.

so, I've been at this reaction for a couple weeks now. all OTC, sodium hypochlorite (30ml of 5%), 10% janitorial strength aqueous ammonia (130ml of 10%), some gelatin (1.5 grams), and heating it to 1/3rd volume.

first of all, I'd like to clarify what on earth you end up with as soon as it has evaporated down to 1/3rd? I know there should be plenty of Chloramine, a little hydrazine hydrate, leftover gelatin, but that should be it? the solution is very much yellow, and because Chloramine is supposed to be yellow, I assume it's the most abundant result of the reaction.

now, I'm only interested in knowing that I can get this reaction right. I don't care about getting tons of hydrazine, I simply want to end up with a little relatively pure hydrazine. I'd even be happy with only a couple milliliters, frankly. in fact, at this point, just knowing FOR SURE that it's hydrazine and only having a milliliter would be REAL SWELL

what I've been trying from this point is to add 1 volume of xylene to the resultant liquid after it's cooled down to room temp. unfortunately I can't find any info on Chloramine's solubility in xylene, but I know that hydrazine is PARTIALLY soluble in it. good enough for me. so I shake it in xylene, and then siphon the xylene layer into a new flask and add a couple milliliters of deionized water and shake again. the idea, of course, being that there ought to be SOME hydrazine in that xylene, and hydrazine is far more attracted to water than xylene, so you'd think a few milliliters of water would combine with hydrazine and become a relatively high concentration of hydrazine hydrate?

the water is siphoned out and takes on a pH of 11/11.5 (?!) (which is light brown on regular pH paper). WTF? isn't hydrazine, in its ANHYDROUS FORM, only supposed to get up to 10 (green on pH paper)? with lower and lower pH as is becomes more dilute with water? obviously something's going wrong somewhere, can anyone help?

now, trying to reason through this, most of the ammonia and hypochlorite would have finished reacting after the reaction mixture hit 60C, and they surely wouldn’t be present anymore after it hits 100C (I usually heat up around 110C). so, all that we can be left with in the yellow mixture is what I listed above, and none of those things has a pH of 11 (chloramine's pH is 9)... I'm really confused here.

how stable is hydrazine to oxygen? does it only last for a couple hours when exposed to air or something, then decomposing into ammonia/etc? I know UV breaks it down too...

I've tried the same xylene extraction process with the liquid boiled down to 1/6th and 1/2. the final water extract still has a mysteriously high pH.

does anyone have good ideas for testing the hydrazine?

as I know it's supposed to react a little with copper, I dripped a single drop of my supposed hydrazine hydrate onto two pennies, one modern (only lightly coated with copper, 2.5%, the rest being zinc metal) and one from the 1950's (which is 95% copper and 5% zinc).

after sitting with a drop of the supposed hydrazine overnight, each penny turned very clearly green at the place where the liquid was, with the liquid of course having evaporated by then.

as those results mean nothing to me, I also tried dropping a single droplet of the supposed hydrazine on an open flame

nothing happened.

am I somehow just ending up with ammonia here or what? and if so, why?

*sigh* can anyone interpret these results? anyone have better tests for hydrazine (besides showering yourself in it and seeing if you get cancer)?

BTW, after turning the heat back on after it has foamed to evaporate down to 1/3rd, I’m always OUT OF THE HOUSE. for safety, all I do is perform the reaction next to a big window (there’s no people and hardly any wildlife around here) with a fan blowing directly on the mouth of the reacting flask and out the window. I also get a little dizzy from holding my breath, plugging my nose, and pressing goggles against my face whenever I have to be near the flask (which is as rarely as possible). am I being paranoid here?

and what about Chloramine? I've searched, but can't find any info on its solubility with xylene. it's obviously very soluble in water, as regular chlorine is being phased out in favor of Chloramine to treat public water. does anyone have a link to the chemical structure of Chloramine? Wikipedia usually is very good about putting the structure of chemical compounds with their chemical pages, but not for chloramine.

maybe someone has a suggestion for a fool proof method to extract hydrazine from this yellow liquid? and speaking of yellow liquid, where can one go to get OTC urea? I assume fasting for a day, drinking lots of water and peeing onto a hypochlorite isn't an advised method of getting hydrazine

and here's another question: would adding some gypsum salts, epsom salts, or other drying agents along with the gelatin be a good idea for ending up with less water and more hydrazine? probably not?

and here’s on FINAL question (sorry for all the questions!). I’ve heard that only anhydrous hydrazine can react with an amine to produce an azide (when considering only the hydrazine family anyway). is this true? can hydrazine hydrate work to produce an azide from an amine too? what about if it's very dilute?

P.S. all non-OTC suggestions, while appearing very interesting to me, will not help anything

[Edited on 20-7-2005 by mandarine]

[Edited on 20-7-2005 by mandarine]

[Edited on 20-7-2005 by mandarine]

Hydrazine

What MP of hydrazine sulfate you get by Urea process . can any one tell actually it should be 254 Deg C but its not that after crystln twice

[Edited on 9-9-2005 by nikcorbet]

Search

I am pretty sure this method was already dscussed. Try searching the forum and I am sure you will find something. I remember writing about mekazine.

I cannot remember the patent number but the ketazines can be produced from ketones, ammonia and hypochlorites. THis should be easier for the home chemist. You just mix 2 moles of ammonia fir every mole of hypochlorite to form your chloramine(preferably at 0C) and add this solution to a well stirred mixture of MEK and concentrated ammonia. Gelatine is optional. Ultimately you would use about 10 to 15: 1 ratio for ammonia to hypochlorite. The ammonia to ketone should be more than a 4:1 ratio.

I will let you know if and when I find the patent.

P.S. the ketazines hydrolysis in water is under 10 atmospheres. When strong acids are used, it happens at standard pressure and only a little heat is required.

Hydrazine and a few other " essential reagents " have been topics of great interest for the experimenters who
do not wish to purchase such chemicals for whatever reasons , or who simply prefer to make their own reagents from the most basic precursors . Sometimes this is an academic exercise and revisiting of the work of early researchers experimentation , out of curiosity about
what may have been missed or gone unreported or unrecognized in significance , and also looking for what is very good knowledge but has become "lost art" in the present texts .

When you want to learn about grandpas practical
synthetic methods ....you have to talk to grandpa , or
read his journals and patents and try to glean from those what may still be very useful information today .

It never hurts either for the younger folks to understand that some *very* smart men lived long long ago . And those ancients figured out a few things which shouldn't need to be rediscovered in historical obscurity . Yet older work often seems to be rediscovered and reinvented and revalued in some new way when the technology and materials of the present is applicable in some beneficial way to methods and knowledge of the past . It can be
properly humbling to hear an appropriate "I told you so"
from pages written fifty or a hundred years or more ago ....written in answer to a question it was known
in advance that someone was going to sooner or later be asking and find already answered at least in part

This is what puts the " re " in re-search you know ,
often travelling a path travelled before , but having a
different pair of eyes observing the scenery and
seeing if more can be seen by this traveller than
was recognized by the one(s) who went before ,
and perhaps to add another cumulative list of
footnotes to mark the point of what more is known now ,
than what was the assembled knowledge before .

Greetings to a fellow dinosaur

For I am a grandpa too .....

Just wish I knew when I was young what I know now ,
for life would have been much more fun and profitable
and at a time when I was still young and healthy enough to enjoy it .

By the time you are old enough to know the best of what life is all about .....the best of life is already behind you ,
and this is a cruel irony .

hydrazine precautions.

some reference tables