Pages:
1
2
3
4 |
halogen
Hazard to Others
Posts: 372
Registered: 18-4-2004
Member Is Offline
Mood: No Mood
|
|
Organic Hypochlorites
-So i dont know what to call it-
How about methyl hypochlorite?
CH3OH+HClO-->CH3ClO+H2O
or
(CH3)2O+Cl2O-->2CH3ClO
Edited by Chemoleo: Changed title to something more comprehensible
[Edited on 27-10-2004 by chemoleo]
[Edited on 25-6-2007 by halogen]
F. de Lalande and M. Prud'homme showed that a mixture of boric oxide and sodium chloride is decomposed in a stream of dry air or oxygen at a red heat
with the evolution of chlorine.
|
|
KABOOOM(pyrojustforfun)
Hazard to Others
Posts: 254
Registered: 12-10-2002
Location: Iran (pseudoislamic dictatorship of)
Member Is Offline
Mood: exuviating!
|
|
you'll just oxidize the methanol to formaldehyde and formic acid. other primary and secondary alcohols can be oxidized this way. only tertiary
alcohols can form hypochlorous esters eg t-butyl hypochloite is a lachrymator and unstable liquide which is formed by passing chlorine in an alkaline
solution of t-butyl alcohol (taken from penguin dictionary of chemistry) I don't see why dripping t-butanol into bleach wouldn't work.
|
|
halogen
Hazard to Others
Posts: 372
Registered: 18-4-2004
Member Is Offline
Mood: No Mood
|
|
1st, bleach is sodium hypochlorite. (I dont know how that would affect it but I think it would)
2nd, There would be a lot of water so wouldnt hydrolysis set in?
Its only speculation, unfortunately.
[Edited on 25-6-2007 by halogen]
F. de Lalande and M. Prud'homme showed that a mixture of boric oxide and sodium chloride is decomposed in a stream of dry air or oxygen at a red heat
with the evolution of chlorine.
|
|
DDTea
National Hazard
Posts: 940
Registered: 25-2-2003
Location: Freedomland
Member Is Offline
Mood: Degenerate
|
|
Methyl Hypochlorite can easily be formed by the reaction between Methanol and NaOCl...that's why NaOCl is listed as an incompatible chemical on
Methanol's MSDS. It is unstable and explosive, so keep this in mind if you work with it.
|
|
Theoretic
National Hazard
Posts: 776
Registered: 17-6-2003
Location: London, the Land of Sun, Summer and Snow
Member Is Offline
Mood: eating the souls of dust mites
|
|
A good way to prepare methyl hypochlorite would be to react methyl chloride with sodium hypochlorite. This would give a higher yield than methanol +
NaOCl, because NaOH formed would partially decompose your product.
I bet that the compound is a liquid, is explosive, stinks of chlorine bigtime, and isn't good for your fingers.
|
|
The_Davster
A pnictogen
Posts: 2861
Registered: 18-11-2003
Member Is Offline
Mood: .
|
|
I gave methyl hypochlorite a try. A testtube was filled 3/4 with 5.25% bleach and about 5 mL of methanol was added. Small bubbles were released soon
and after a day the bleach had lost all its yellow color. I had been assuming that methyl hypochlorite would be an insoluble liquid that would
settle on the bottom of the testtube. After 3 days there is no separate layer of methyl hypochlorite. So is it in solution? Or were the reaction
conditions not right?
|
|
halogen
Hazard to Others
Posts: 372
Registered: 18-4-2004
Member Is Offline
Mood: No Mood
|
|
1.Youre assuming I did this before...
2. Could it be that methyl hypochlorite is a gas?
3. Where can you get chlorine heptoxide?
[Edited on 11-1-2008 by halogen]
|
|
BromicAcid
International Hazard
Posts: 3250
Registered: 13-7-2003
Location: Wisconsin
Member Is Offline
Mood: Rock n' Roll
|
|
Quote: |
3. Where can you get chlorine heptoxide?
|
I'm fairly certain that it is not shipped by any means of transportation and is, as a concequence, only produced where it is needed on site,
regardless of it being the most stable chlorine oxide. For preparation though the only method that I know of is adding P2O5 to highly concentrated
HClO4 until the Cl2O7 is evolved. Me though, I've got better things to do with my P2O5 and 72%+ HClO4 (Which would take a lot of P2O5 to get to
release any Cl2O7 anyways). I'm sad to say for the most part Cl2O7 is very much inaccessable as far as I know.
|
|
KABOOOM(pyrojustforfun)
Hazard to Others
Posts: 254
Registered: 12-10-2002
Location: Iran (pseudoislamic dictatorship of)
Member Is Offline
Mood: exuviating!
|
|
I was wrong
<i>only tertiary alcohols can form hypochlorous esters</i>
other alcohols can form hypochlorous esters too. but they are toooo unstable
from <a href="http://www.chemistry.mcmaster.ca/~chem2o6/labmanual/expt7/2o6exp7.html"
target="_blank">http://www.chemistry.mcmaster.ca/~chem2o6/labmanual/expt7/2o6exp7.html</a>:
<blockquote>quote:<hr>Aqueous sodium hypochlorite (NaOCl), or common household bleach, can be used to oxidize secondary alcohols to
ketones. The reaction occurs more rapidly under acidic conditions, so it is thought (we're not actually sure) that the actual oxidizing agent is
hypochlorous acid (HOCl), generated by the acid base reaction between sodium hypochlorite and acetic acid...
...In alcohol oxidations, the reaction probably proceeds via E2 elimination of the alkyl hypochlorite produced by reaction of the initial alcohol with
HOCl<hr></blockquote>
also take a look at:
<a href="http://www.wellesley.edu/Chemistry/chem211lab/Orgo_Lab_Manual/LabManual/week9.html"
target="_blank">http://www.wellesley.edu/Chemistry/chem211lab/Orgo_Lab_Manual/LabManual/week9.html</a>
------------------
<a href="http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv4p0125" target="_blank">tert-Butyl Hypochlorite
synthesis</a>
<a href="http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv5p0184" target="_blank">another (better) tert-Butyl
Hypochlorite synthesis</a>
I still think t-alkyl hypochlorites are more stable 'cause they can't be oxidized=dehydrochlorated. in other words there's no hydrogen
attached to the carbon which has the -OCl group to be removed with the Cl as HCl
|
|
KABOOOM(pyrojustforfun)
Hazard to Others
Posts: 254
Registered: 12-10-2002
Location: Iran (pseudoislamic dictatorship of)
Member Is Offline
Mood: exuviating!
|
|
I should apology to halogen
because of my post in his "oxyazides?".
now that is in Detritus and I couldn't reply to that thread...I see he hasn't been online since 23-5-2004 so I thought he might have
subscribed the thread he has made... sorry for my being off topic anyway.
[Edited on 30-6-2004 by KABOOOM(pyrojustforfun)]
|
|
BromicAcid
International Hazard
Posts: 3250
Registered: 13-7-2003
Location: Wisconsin
Member Is Offline
Mood: Rock n' Roll
|
|
Often I'll just randomly open up a chemistry book and browse through the index looking for anything that catches my eye, today I was browsing the
ACS archives, specifically from Feb, 1925 when I ran across an article titled:
Hypochlorous Acid and the Alkyl Hypochlorites
By M. C. Taylor, R. B. MacMullin and C. A. Gammal
Huzzah, I rejoiced, I remembered this thread and made some photocopies. No mention of any explosive properties of methyl or ethyl hypochlorite
although preparations and properties are described.
Here are some highlights:
Quote: | Our knowledge of the alkyl hypochlorites begins with the work of Sandmeyer (1) in 1885 who prepared methyl hypochlorite by chlorinating a mixture of
alcohol and sodium hydroxide. The esters are relatively insoluble in water, and separate as yellow oils, unstable towards heat and light and
possessing very irritating odors. Very recently Chattaway and Backeberg (2) described other hypochlorite including the various isomeric propyl,
butyl, and amyl hypochlorites. They found that the hypochlorites of tertiary alcohols are much more stable then those of the corresponding primary
and secondary alcohols.
.......
The unstable nature of the pure material made is unsuitable for use in a technical process, but it was found that a solution of the ester in carbon
tetrachloride, or any other solvent immisible with water, was stable for several hours below 25C.
.......
Twenty to 25 g of precipitated chalk or ground limestone is added to a liter of water and the mixture chlorinated with stirring until about 25 g of
chlorine has been absorbed. With this excess chalk, the available chlorine is present almost entirely as hypochlorous acid. The excess of carbonated
is filtered off and the filtrate shaken immediately with and equal volume of carbon tetrachloride containing about 2% or more of ethyl alcohol. About
two minutes shaking is sufficient to cause reaction between hypochlorous acid and alcohol to such an extent that the greater portion of chlorine is
removed as ethyl hypochlorite from the water to the solvent layer which can then be separated.
.......
A pure solution of ethyl hypochlorite in carbon tetrachloride made in this way lost only 10% of the available chlorine on standing for two days at 20C
in the diffused light of the laboratory.
.......
Such a solution of ethyl hypochlorite liberates iodine quantitatively form potassium iodide and acetic acid. It reacts rapidly with phenol, aniline,
methylaniline, sodium picrate and similar easily oxidized substances and in general shows most of the reactive properties of hypochlorous acid. When
ethylene is passed into a mixture of ethyl hypochlorite, slightly acidified water and carbon tetrachloride, absorption occurs with the probable
formation of ethylene chlorohydrin, which dissolves in the carbon tetrachloride. We did not, however, carry out this experiment to the point of
isolating the chlorohydrin.
.......
Ethyl hypochlorite decomposes on standing, giving high yields of ethyl acetate, probably by the following steps:
C2H5OCl ----> CH3CHO + HCl
CH3CHO + C2H5OCl ----> CH3COOC2H5 + HCl
.......
Ethyl hypochlorite reacts with alkali to form alkali hypochlorite free form chlorides.
.......
The constitution of the ethyl hypochlorite has been shown by our work to be that of a true ester. The oil was prepared by the method of Sandmeyer,
washed with sodium bicarbonate solution and dried with calcium chloride. It was kept in the dark at 0C during analysis. Six different determinations
of chlorine content were made, of which the average value is 44.13% as compared with the calculated value of 44.05.
.......
If the substance had been a double compound of one molecule of alcohol to one of acid, EtOH.HOCl, the molecular weight would have been 98.5. This
shows that the compound which we have assumed to be ethyl hypochlorite is a true ester. Although, as we will show below, hypochlorite is largely
hydrolyzed in water, its insolubility in water permits esterfication by removing the reaction product from the water phase. Solvents aid in this
removal of ester from water, giving even greater yields of ester then when no solvent is used.
.......
We investigated the formation of hypochlorous acid esters of various alcohols by the method which Sandmeyer used for preparing ethyl and methyl
hypochlorite. Yellow, insoluble, unstable oils were obtained with propyl, isopropyl, sec.butyl, tert.butyl, isoamyl, sec.amyl, and tert.amyl
alcohols. Benzyl alcohol is oxidized to benzaldehyde by hypochlorous acid. Glycerol, glycol and ethylene chlorohydrin gave no appreciable amounts of
insoluble oil. |
(1) Sandmeyer, Ber., 18, 1767 (1885); 19, 857 (1886)
(2) Chattaway and Backeberg, J. Chem. Soc., 123, 2999 (1923).
Hope someone found this interesting. So as of now I've read up on alkyl hypochlorites, alkyl perchlorates, and understandably not alkyl
chlorites, however what about alkyl chlorates?
|
|
Blaster
Hazard to Self
Posts: 54
Registered: 7-11-2003
Location: UK
Member Is Offline
Mood: perchloric!
|
|
I just thought I'd add a bit to Bromic Acid's post above.
To my knowledge the alkyl chlorites and chlorates have not been isolated. They are just too unstable. The extreme instability of the perchlorates has
of course been discussed!
Hypochlorous esters are best prepared by the action of Chlorine gas on a cooled solution of the appropriate alcohol in 10% aqueous NaOH. However, they
can also be prep'd by the action of the alcohol on a conc. solution of HOCl or by passing Cl2O into the alcohol and precipitating the liquid
ester with water. (Sandmeyer's ref as quoted by Bromic Acid).
The boiling points are 12'C and 36'C for the methyl and ethyl esters respectively. They explode (far less violently than the perchlorate
esters) when ignited or exposed to a bright light and decompose on standing to the appropriate aldehyde.
|
|
Axt
National Hazard
Posts: 806
Registered: 28-1-2003
Member Is Offline
Mood: No Mood
|
|
I made EtOCl a while ago, by the method Blaster has just mentioned. Using HCl/MnO2 to generate the chlorine, with the EtOH/NaOH in a measuring
cylinder in a jar of cold water containing prilled AN. The yellow EtOCl seperates quickly and is easily extracted from the top of the liquid.
Acts simular to MEKP, though less violent and accompanied by a large fireball. Below is the ignition of ~5 drops if I remember right.
<center><img src="http://www.sciencemadness.org/scipics/axt/etoclapp.jpg"> -----> <img
src="http://www.sciencemadness.org/scipics/axt/etocl.jpg"></center>
[Edited on 9-12-2005 by Axt]
|
|
chemoleo
Biochemicus Energeticus
Posts: 3005
Registered: 23-7-2003
Location: England Germany
Member Is Offline
Mood: crystalline
|
|
I wonder if there are similar hypochlorous esters for i.e. amino, or nitro ethanol? This should make the compound more interesting, but probably also
less stable.
Although I have my doubts this could be prepared by direct chlorination.
Anyway, good work, who'd have thought it's this easy!
Axt, could you comment on the shock sensitivity, and flammability? How did you ignite it?
Never Stop to Begin, and Never Begin to Stop...
Tolerance is good. But not with the intolerant! (Wilhelm Busch)
|
|
Axt
National Hazard
Posts: 806
Registered: 28-1-2003
Member Is Offline
Mood: No Mood
|
|
I cant give any more info, only did it once. I chucked a match at it. It takes fire <i>very</i> easily.
If its extracted straight off the top and ignited it always leaves burney bits left behind, like MEKP does if it isnt dried. Salting it out helps
somewhat, but I expect to get remnant EtOH out you would have to distill it, not something im going to do.<br><br>
|
|
kazaa81
Hazard to Others
Posts: 368
Registered: 30-4-2004
Member Is Offline
Mood: ok
|
|
Question...
Hallo to all,
I post a question that is in my mind: won't be common blach too dilute to react with ethyl or methyl alchohol?
I've not yet tested this experiment because if 5% NaClO react indeed, I will be unprepared...
Any other suitable organic hypochlorites?
Thanks for collaboration.
|
|
The_Davster
A pnictogen
Posts: 2861
Registered: 18-11-2003
Member Is Offline
Mood: .
|
|
I gave ethyl hypochlorite a go this evening. 25mL of 10% NaOH was mixed with 25mL of denatured ethanol. These 50mL of liquid was placed in a
graduated cylinder and placed in a snow/water bath. Chlorine produced via HCl +NaOCl was bubbled through for around 1h. The ammount of chlorine
bubbled through was produced by the complete reaction of 60mL 31.45% HCl with excess bleach. After around the half hour mark I added around 1g more
of NaOH to the cylinder because I was worried that HCl gas carry-over from the gas production setup would react with the NaOH instead of the chlorine
reacting with the NaOH. The solution was a light green upon completion of bubbling the chlorine through. Smelled unusual, not bad kind of pleasant
actually although the smell was different from that of ethanol. I recieved no separate layer of liquid on top in the graduated cylinder. I know that
some ethyl hypochlorite was produced as when I lit samples of the solution on fire it burned orange instead of the charastic light blue of alcohol.
There was still some blue in the flame indicating excess ethanol left over.
Thoughts...(especially on why I got no separate layer formed-I am thinking that I should have bubbled more chlorine through, but I am not completly
sure)
EDIT: I need a gas mask *cough*
[Edited on 18-12-2004 by rogue chemist]
|
|
Axt
National Hazard
Posts: 806
Registered: 28-1-2003
Member Is Offline
Mood: No Mood
|
|
Water!
12g NaOH, 12g EtOH, 100ml water, bubble chlorine through that. It only takes a few minutes but its not very interesting. The methanol derivative may
be more interesting, though you would have to keep it cool to prevent evaporation, or better, catch the pure stuff in a condenser.
I expect NaOH/EtOH will give the orange flame, as is.
[Edited on 18-12-2004 by Axt]
|
|
The_Davster
A pnictogen
Posts: 2861
Registered: 18-11-2003
Member Is Offline
Mood: .
|
|
Thanks Axt
Just looking at the ratios that you just posted I realize that I used way to much ethanol and not enough water. "25mL of 10% NaOH" was all
the water I had in there. The ethyl hypochlorite must be semi-soluble in
ethanol solutions as well which would explain the green colour but not a separate layer.
I'll try this again tomorow.
I may be able to try the methyl ester soon as well seeing as it is a Canadian winter here so I should have low enough temperatures to keep the methyl
ester liquid.
|
|
The_Davster
A pnictogen
Posts: 2861
Registered: 18-11-2003
Member Is Offline
Mood: .
|
|
I tried it again, with the ammounts Axt posted. It worked quite well, I got nearly 8mL of ethyl hypochlorite. It smells quite terrible actually.
Just from washing out the glassware inside the house the room I was in reeked of it afterwards. After I removed the majority of the EH from the
surface with an eyedropper I left about 1mL of EH on the surface of the graduated cylinder. I bubbled chlorine through for quite some time after that
and about 30min later the EH was on the bottom of the graduated cylinder. Chloroethyl hypochlorite anyone?
Does anyone know anything about the toxicity of ethyl hypochlorite? I spilled a single drop on my wrist( just missed the glove) and I am feeling
quite lightheaded right now, I feel quite strange and am not thinking to clearly right now. I even had difficulty remembering what the compound I had
just made was when I started posting this reply.
|
|
mark
Harmless
Posts: 25
Registered: 23-10-2004
Member Is Offline
Mood: No Mood
|
|
Could you be sensitive to chloroform? I guess this reaction may be possible. Chlorine on sodium hydroxide to produce sodium hypochlorite reacting
with ethanol to produce chloroform and getting suspended in the ethyl hypochlorite?
Why I am at I once tried it, except I used no water. After four tries I gave up but some gave me a lot yellow liquid that didn’t burn different to
Metho except using a yellow flame. The solution was prepared by bubbling chlorine through EtOH and NaOH solution. The solution was prepared by
dissolving NaOH in warm EtOH. On one I did actually get a crystalline suspension that dissolved after more chlorine was dissolved in it.
|
|
Esplosivo
Hazard to Others
Posts: 491
Registered: 7-2-2004
Location: Mediterranean
Member Is Offline
Mood: Quantized
|
|
I was rereading this thread and it struck me that on passing chlorine through ethanol will cause the ethanol to be oxidized to ethanal, which will
then be chorinated to produce chloral as I've read. The presence of NaOH is known to 'convert' chloral into chloroform. Why
doesn't this occur here also? I mean, what was produced by Axt is surely not chloroform (which is relatively non-combustible). It can't be
chloral either due to the presence of a hydroxide.
In short, what is/are the differences in the synthesis of chloral and the organic hypochlorites? I'm confused.
Theory guides, experiment decides.
|
|
BromicAcid
International Hazard
Posts: 3250
Registered: 13-7-2003
Location: Wisconsin
Member Is Offline
Mood: Rock n' Roll
|
|
I didn't know it till today, but orgsyn.org has two preparations for tert-butylhypochlorite, it is of course more stable then the methyl and
ethyl versions, apparent by the fact that the creators of one of the procedures made batches in upwards of 700 ml at a time, it is interesting to note
that the compound decomposes slowly to methyl chloride and acetone, and that irradiation of the product with UV light leads to evolution of the gasses
so fast and such a marked increase in temperature that the ester begins to boil.
|
|
Axt
National Hazard
Posts: 806
Registered: 28-1-2003
Member Is Offline
Mood: No Mood
|
|
I've no answer Esplosivo, but its made by the reaction of hypochlorite rather then free Cl2, Ethyl hypochlorite also seperates readily from a
solution of NaOCl/ethanol/acetic acid. Its not much better then a very flammable liquid, though explodes when confined.
If you have PATR, check Vol 7, H 262 for a decent description.
|
|
mark
Harmless
Posts: 25
Registered: 23-10-2004
Member Is Offline
Mood: No Mood
|
|
Can anyone specify the conditions under which the reaction takes place? With the chlorine method all that seems to happening, Is Cl2 on NaOH forms
NaOCl than the NaOCl reacts with EtOH to form C2H5OCl (right?). Therefore there is no need for an acid?
However, in Axt’s second method he uses an acid? Is this just to catalyze the reaction or is there something I am missing? If it just a catalyst is
their another acid that can replace it?
|
|
Pages:
1
2
3
4 |