Sciencemadness Discussion Board

Carbon Tetrachloride CCl4

BromicAcid - 27-1-2004 at 12:33

This has always been one of the reagents that I've wanted but been unable to get due to environmental regulations and it seems many other people want it to, so... time to start a thread! The ways that I knew of to get make it included:

CH4 + 4Cl2 ---> CCl4 + 4HCl

But this one requires somewhat high temperatures, although I am tempted to try it, using sodium acetate plus hydroxide to form the methane and reacting it with chlorine in a glass tube filled with broken pottery. But it seems like it will be such a hassle for such a tiny bit of CCl4.

So what about the reaction of carbon disulfide with chlorine in the presence of iron I asked myself.

CS2 + 3Cl2 --Fe--> CCl4 + S2Cl2

Then heat that with more carbon disulfide and...

CS2 + 2S2Cl2 ----> CCl4 + 6S

But the hurdle for this reaction is obtaining carbon disulfide. Sure, I can make it but it's a messy process and of course dangerous, so why would I want to use what little bit of that perfectly good solvent I have to make a tiny amount of a different. Plus this is run at elevated temperatures, not terribly high but with carbon disulfide and potentially volitle sulfur compounds I get a little worried (well actually I pretend to get worried to appease my reasonable self).

So I did some research in the library and came up with:

CaCN2 + HCl(g) ---> CaCl2 + CCl4(g) + 2NH3

At elevated temperatures, doesn't look like a bad reaction but where to get the calcium cyanamide?

Also found:

5C + 2CaCl2 ----> CCl4(g) + 2CaC2

Of course seeing something that produces calcium carbide you might be automatically thinking that this reaction takes place in an electric arc furnace. You would be right, and that is the hurdle that this specific reaction poses.

Finally I come to what might be the most feasible reaction:

CHCl3 + 2ICl ----> CCl4 + HCl + I2

That seems somewhat reasonable if you are willing to trade chloroform for carbon tetrachloride, which I'm willing to do. Also there is the fact that the haloform reaction also produces amounts of carbon tetrachloride especially if the halogen is used in excess as pointed out by someone on this board.

So everyone, what reactions sound like they could be most easily turned into a procedure to make carbon tetrachloride that us mad scientists could use?

I've made my choice on which one I want to try when it gets warmer but I think I'll keep it a secret till some more people comment on theirs. Also, does anyone have any other reasonable synthesis for CCl4, that might prove to be even more helpful!

[Edited on 1/27/2004 by BromicAcid]

vulture - 27-1-2004 at 12:50

At elevated temperatures, doesn't look like a bad reaction but where to get the calcium cyanamide

Certain fertilizers contain calciumcyanimide. Look for nitrogen rich chalk or something.

Good News :)

chemoleo - 27-1-2004 at 13:00

Quote:
Originally posted by BromicAcid

So I did some research in the library and came up with:

CaCN2 + HCl(g) ---> CaCl2 + CCl4(g) + 2NH3

At elevated temperatures, doesn't look like a bad reaction but where to get the calcium cyanamide?


Very interesting. In fact it is not hard to get hold of calcium cyanamide! It is a common component of certain fertilisers, and is, as far as I know, as high as 70%. It is a black substance - although this maybe related to the remaining 30 %. My book doesn't state colour.
In fact, calcium cyanamide seems an interesting compound for other purposes- hydrolyiss with H2O (dont know what temp) yields free cyanamide (crystalline, mp 45 deg C) according to CaNCN+H2O +CO2--> CaCO3 + H2NCN. This dimerises at 80dg C to (H2N)2C=NCN, which can be converted to melamine (triamino cyanuric acid) by heating in NH3. (Maybe this warrants another thread, the uses of cyanamide)

Anyway, BromicAcid, it would be good if you found out what conditions are required for this reaction to occur. As I said, calcium cyanamide is easy to obtain :)

Edit - oops, overlap with vulture.

[Edited on 27-1-2004 by chemoleo]

Calcium Cyanimide

Alchemist - 27-1-2004 at 15:24

If ya find exactly where to get calcium cyanimide please let us all know, I have been trying for about a year now. I have tried 3 really good ag's in my area and have called several others with no luck. I asked for lime-nitrogen and also calcium cyanimide by name. One place over the phone said it was not used for fertiliser anymore and has been replaced with better nitrogen fertilisers (names not given to me). Another Ag-store said they could order it so I said OK. A few days latter they called back and said it was no longer avaible. I live in Calif.. Good luck! I really do hope you find a good source.

[Edited on 27-1-2004 by Alchemist]

[Edited on 27-1-2004 by Alchemist]

chemoleo - 27-1-2004 at 16:57

as far as I remember they are lawn fertilisers. they go as high as 70%. black grains. I once tried to play with it myself :) - I would be very surprised to hear that they don't exist anywhere in the US if they exist here in Europe!

UV rays!

chloric1 - 27-1-2004 at 18:41

Bromic acid- Dude!, Forget elevated temperatures. Just take your haloform reaction chloroform and bubble chlorine through it. Then you can set it in ordinary sunlight at 25C!:D Heck if its the cold temperatues that bother you, put a tight fitting stopper in the flask and put it in a cozy sunny window sil for about 5 or 6 hours. Maybe it may take a few days of this but I need to try it myself. But UV rays are all you need to chlorinate at room temp according to my organic chemistry text.

[Edited on 1/28/2004 by chloric1]

Mumbles - 27-1-2004 at 19:12

Winter UV rays are not as strong. It would take much longer than in summer, even if the liquid was warmed to the same temp. It is a nice idea to try in the warmer months. Just another thing added to my to do list.

BromicAcid - 27-1-2004 at 19:14

Chloric1, yeah, I thought about UV rays. I once used chloroform to extract bromine form a solution, the red color disappeared in short order after it sat in the sun and the lid bobbed on the top from releasing fumes of CHCl3/CCl3Br/ Br2/HBr from the heat and sunlight. Maybe I'll give that a try but chloroform has such crummy yields. Also, you wouldn't even need light as I got the feeling that the reaction of chloroform with iodinemonochloride was somewhat catalytic. The reaction yields iodine which would react with the chlorine and make iodinemonochloride and the reaction would continue. Both are still better then making carbon disulfide in any quantity.

Hows about this. I wouldn't consider it as being useful but....

CH4 + Cl2 ----> CCl4 + 4HCl

Run the exit gasses through a condesner to get out the chlorinated hydrocarbons and react the remaining HCl with calcium cyanamide:

4CaCN2 + 4HCl(g) ---> 4CaCl2 + 4CCl4(g) + 8NH3

Finally take the calcium chloride byproduct and react with carbon:

10C + 4CaCl2 ----> 2CCl4(g) + 4CaC2

I just thought that it was weird that it worked out that way, the 'waste' products of two of the reactions could be put back into two of the other reactions.

Tommorow at school I will find the reference for the cyanimide reaction and maybe try and find a source for it too. Wish me luck!
;)

[Edited on 1/28/2004 by BromicAcid]

Polverone - 27-1-2004 at 20:25

Calcium cyanamide is formed by the thermal decomposition of calcium cyanate. Calcium cyanate can be prepared like the alkali metal cyanates (heating its carbonate or hydroxide with urea). So calcium cyanamide can be formed by strongly heating urea with calcium carbonate or hydroxide.

BromicAcid - 2-2-2004 at 15:37

Quote:

Tommorow at school I will find the reference for the cyanimide reaction and maybe try and find a source for it too. Wish me luck!
~Bromic Acid

Finally got around to doing that today. Looked up the reaction in the "Encyclopedia of Chemical Reactions" again and this is everything it says:
Quote:

CaCN2
HCl
Hydrogen Chloride is passed over heated calcium cyanamide, yielding the products shown in the equation.
CaCN2 + HCl(g) ---> CaCl2 + CCl4(g) + 2NH3
Montemartini and Losana, Giorn. Chim. ind. applicata, 6, 325

And that's it, couldn't get the material to look up more, maybe someone else out there? Plus I looked up more on the Cyanimide, looks like it is still avalible in fertilizers, guess I've got some hunting to do come summer.

BromicAcid - 9-2-2004 at 14:25

"Another reply, that could only mean Bromic's been back at the library again!"

Yes, that's true.... Anyway, turns out that there's a method to make carbon tetrachloride by reacting methanol with a sulfur chloride or just with chlorine in the presence of sulfur. All I got in the reaction description was that the reaction occurs under pressure... yeah, it was pretty vague. Well, turns out that some companies that produce CCl4 have switched over to this method so I would expect to be able to find something on it. I googled and looked around at school but came up empty handed. Anyone have something else to add on this?

chloric1 - 23-3-2004 at 10:56

Quote:
Originally posted by Mumbles
Winter UV rays are not as strong. It would take much longer than in summer, even if the liquid was warmed to the same temp.


Yeh I see your point. Now it is late March and by April 30th we have the same intensisty sunlight as August 1st here at 39 degrees North!!! So I dont have long to wait for UV experiements. Plus, I dont ahve the motivation to do shit during the colder months anyhow.

Incidently, I see plenty of 4 watt shortwave(235 nm) UV lamps on ebay. I have one that runs off NiMH and it will make tiny amounts of ozone in a few minutes! Dont know if this would be enough power but if the flask of chlorinated chloroform was close enough... I dunno maybe.;) Also a a strong acid mix of HCl and FeCl3 with citirc acid added, should give off CO2 and FeCl2 in sunlight! I wanna do this too!

Quantum - 23-3-2004 at 13:08

Quote:

My book doesn't state colour.

I googled for a MSDS and found one that said the color is white to off white. The fertalizer must have impurities.
MSDS
You need to click on the MSDS link to get the PDF file.

Tetrachloromethane seems like a very interesting chemical but its toxic effects have shattered my rose colored glasses.:D Anyway I don't even have
CHCl3 so an even more dangerous solvent is out of the question for the time being.

BromicAcid - 23-9-2004 at 15:27

I've been keeping an eye out for methods of making CCl4 for a while now and I found some interesting methods of manufacture.

One thing that I didn't mention further up was the further chlorination and subsequent splitting of C-C bonds in already chlorinated hydrocarbons.

I found examples of reacting the highly available Cl2CCCl2 with chlorine at moderate temperature and yielding carbon tet almost quantitatively. Cl2CCClH which is also quite avilible can do the same. Although it was probably common knowledge to many of you, at the time of working in this thread I didn't know these two chemicals were so readily avalible (at least in the states) so I didn't consider the possibilities. But now...

Organikum, any input on working with a chlorinating apparatus that you could put in this thread for completeness?

Other interesting things that I found, hydrolyzing tetrachloroethene in the presence of copper yeilds trichloroacetic acid, phosgene, and carbon tetrachloride among other products. Similar case with 1,1,2-trichloroethene.

One other thing, reacting tetrachloroethene with nitric oxide produces various nitrated chlorinated carbons, chloropicrin and carbon tetrachloride among them.

Mumbles - 24-9-2004 at 19:46

Just thought I'd comment on the black color. It is from graphite. The reason it is sold in up to 70% purity is because that is the purity of industrial production. It is produced by electrolysis of Ca(OH)2/CaO, (maybe Carbon, or they use the carbonate) and Urea(don't hold me to those chems) with graphite electrodes. There is impurity of Ca(OH)2, CaO, and graphite of course.

Back to the topic at hand. I had read something about the decomposition of Hexachloroethane in some compositions to give carbon tetrachloride. Perhaps this could be optomised. I believe the reaction with Chlorine will give the tetrachloride at semi-reasonable temps(less that 500C).

garage chemist - 25-9-2004 at 00:25

The calcium cyanamide fertilizer is made by reacting powdered calcium carbide with nitrogen (from the air) at about 1000°C.The process is exothermic.
It is one of the very few processes that uses gaseous nitrogen as a precursor.

The reaction goes as follows:

CaC2 + N2 ---> CaCN2 + C(this causes the black color!)

If you heat a lump of CaC2 in air, you will notice that it goes black. This is because of this reaction!

During war, there was an attempt to use CaCN2 as a source for urgently needed nitrogen compounds (HNO3 for production of explosives). The CaCN2 was hydrolyzed with water under pressure to give ammonia, which could then be combusted into NO2.
The process was too expensive to be of any use, because of the very energy- consuming production of CaC2.

Theoretic - 20-10-2004 at 00:24

You could use ammonium cyanamide instead of CaCN2, the CaCl2 residue can prevent the reaction happening to the full.

BromicAcid - 20-10-2004 at 09:53

Is ammonium cyanimide significantly easier to acquire. I must confess that I specifically searched for calcium cyanimide so I really don't know of the occurrence of ammonium cyanimide, but if it is a reasonably easy to acquire chemical I might give it a shot.

Right now I am planning on just chlorinating my hexachloroethane further with chlorine gas and cleaving the C-C bond, so I am going to need some reaction tube and such. I better get to work.....

chemoleo - 20-10-2004 at 11:59

Right, so why do you think CaCl2 would inhibit the reaction? I don't follow this.
Also - I'd bet that 'ammonium cyanamide' isn't exactly OTC, nor easily prepared - that is if it exists at all (i.e. I could imagine it'd polymerise or decompose to something else).

Theoretic - 21-10-2004 at 05:31

Calcium chloride would eventually predominate in the solid residue from hydrochlorination, the remaining reactant will be spread throughout the volume of waste CaCl2 and will react slowly.
Ammonium cyanamide doesn't produce any relevant Google hits, however when calcium cyanamide is made into a slurry and carbonated with CO2, cyanamide (hydrogen cyanamide) NH2CN is made along with CaCO3. If you make a slurry of finely powdered calcium cyanamide and add ammonium carbonate, this will hopefully give you CaCO3 and (NH4)2CN2 solution. Another advantage of ACN is that you'll need less HCl gas, because at high t NH4Cl decomposes and HCl is freed, this doesn't happen with CaCl2.

chemoleo - 21-10-2004 at 18:40

Theoretic - sorry but I don't quite see the point.
It's natural for any reaction to slow down once reactants are depleted. You are lessening the concentration of CaCN2, and hence lessening the rate of reaction. Although I agree that mixing of the reactants may be a problem that could be avoided if things were in solution. But this is not the case here anyway as this is a solid state reaction.

Anyway, more importantly, you say yourself that CO2 liberates cyanamide. Meaning that H2CO3 is a stronger acid. Meaning that H2NCN is an extremely weak acid, as it is even displaced by CO2.
Therefore I should doubt ammonium cyanamide is stable unless it is thoroughly excluded from air (containing CO2). In addition - H2NCN is quite prone to polymerisation ( I think I posted that elsewhere) - and H2NCN would certainly exist in a displacement reaction you describe (CaCN2 + (NH4)2CO3 -> CaCO3 + (NH4)2NCN), simply becuase of equilibrium --> therefore, rather than getting ammonium cyanamide, you'd get various polymerisation products.

Anyway - this is much speculation for both of us - to be honest I think it's much easier just to go with the fertiliser 'Kalkstickstoff' CaCN2 and accept some minor losses, if that.
Converting it to some unstable air-sensitive ammonia form? No thanks!

Regardless - someone has to try before we speculate too much!

Theoretic - 22-10-2004 at 13:26

"Theoretic - sorry but I don't quite see the point.
It's natural for any reaction to slow down once reactants are depleted. You are lessening the concentration of CaCN2, and hence lessening the rate of reaction."

That's my point, using ammonium cyanamide would keep the concentration of the solid reactant 100%, as ammonia formed in the reaction would evaporate off, as would all of the reaction products. The gaseous reactant concentration wouldn't decrease, I think if anyone tries it that would be the design solution, a current of HCl gas flowing over ACN or CCN solid, ammonia gas being carried away. But anyway, I think you're right abouit polymerisation and everything, I also now realised that ACN will probably decompose at the temperatures needed for the reaction to happen.

"to be honest I think it's much easier just to go with the fertiliser 'Kalkstickstoff' CaCN2"

Fertilizer? Hmmm... One application where ACN would be suitable is high-N-content nitrogen fertilizer, being universal application as well, since the ammonia portion would be available to plants instantly, and the cyanamide would release its N content gradually. ACN would have the N content higher that NH4NO3 or urea, being second only to ammonia itself, this would slash transportation costs. Hydrolysis by air moisture + CO2 could be avoided if the fertilizer was contained in plastic bags, which is easy. For CCl4, I agree with you, CCN is better.

HNO3 - 18-12-2004 at 09:03

BromicAcid:
I wondered if Tetrachloromethane could be produced from the following reaction: CCl3H + NaOCl -> CCl4 + NaOH.

BromicAcid - 18-12-2004 at 09:19

Quote:
The haloforms, when prepared by the haloform reaction, are contaminated to a greater or less degree by the corresponding tetrahalomethanes. This is due to the action of the hypohalites on the haloforms by which the latter are converted into the corresponding tetrahalogen compounds:

CHX3 + NaOX = CX4 + NaOH.

This is a general reaction (83, 73, 8, 38); it often becomes the principal reaction when dilute solutions are used. Thus, Wallach (198) found that in the formation of bromoform from hypobromite and acetone in very dilute solutions, the reaction was slow and that carbon tetrabromide was the chief product. This influence of the pH on the course of reactions involving hypohalites is frequently noticed (105, 119, 79).

(198) WALLACH: Ann. 276, 149 (1893).
(105) KOLTHOFF: Pharm. Weekbald 62, 652 (1925).
(119) VAN DER LEE: Chem. Weekblad 23, 444 (1926).
(79) HATCHER AND MEELLER: Trans. Roy. SOC. Can. [3] 23, Sect. 3, 35 (1929).


But it's hard to tell how far this reaction goes, the boiling points of CCl4 (Bp 76C) and CHCl3 (Bp 61C) are so similar that it's difficult to tell them apart by boiling point, and their physical properties are also very similar. Separation would be a pain, in the physical sense, although you might be able to do something like take your impure CCl4 and add in solid NaOH, probably the reaction would only proceed with the chloroform, leaving one with the CCl4 to be distilled.

BTW, I think I got that quote from somewhere on this site.

alchemie - 18-12-2004 at 17:06

Maybe CH2Cl2 could also be used.
You can get it OTC, from paint strippers, in much bigger amounts than you could synthesize CHCl3 using the haloform reaction.

On the other hand it would be harder to separate a mixture of the three halometanes by distillation. so maybe it´s better to stick to the chloroform only.


As to other methods of separation, here´s what the Merck 13th edition says about the water solubility of the three compounds:

CH2Cl2 - "Soluble in ~50 parts water" (wich means roughly 1.3 ml dissolve in 50ml of water))

CHCl3 - "One ml dissolves in about 200 ml water at 25°"

CCl4 - "One ml dissolves in 2000 ml water"

The number speak for themselves.
I Think that you could get away by washing the mixture with water, as long as you have a significant percentage of CCl4 in the mixture, as the any of the other two are much more soluble in water.

BromicAcid - 18-12-2004 at 17:14

You cannot use the haloform reaction on CH2Cl2, it is a reaction that is specific for methyl ketones. I think the basic premise of it has been covered in the garage experiments with trichloromethane. Washing the product repeatedly with water might be a way to make a purer product, but in the process you are going to contaminate a lot of water, halocarbons are not environmentally friendly.

You could start from CH2Cl2 and either bubble chlorine through it with iodine as a catalyst or also as mentioned above let it sit for a long period of time in contact with a hypohalite with agitation, however I don't have much information on what conditions best promote chlorination through this kind of situation (Note, this is not the haloform reaction), just that it can occur, the information that I found specifies in dilute situations and makes no mention of actively trying to make a tetrahalomethane compound from say a di or tri halo methane compound.

alchemie - 18-12-2004 at 19:48

I was refering to reacting CH2Cl2 with Cl2. Not using CH2Cl2 in the haloform reaction(wich is impossible).

Anyway the important thing I wanted to say was that is is possible to separate CHCl3 (or CH2Cl2 or both) from CCl4 just by washing with water, as therir water solubilities are so different.

Maybe I didn´t explain myself right. Sorry.

BromicAcid - 18-12-2004 at 20:09

I read through your post too quickly, I thought that you wanted to use the haloform reaction on CH2Cl2, you didn't mention trying to use chlorine gas. But yeah, as discussed before you could use something like tetrachloroethane which is widely available and react it with chlorine and get your tetrachloromethane or as you said react dichloromethane with chlorine.

Separation by distillation as you said would be difficult w/o fractioning several times. Though there may be chemical treatments, chloroform will react with solid KOH but carbon tet will not, so distillation from this may be possible.

Blackout - 30-12-2004 at 07:17

TiCl4 + C => CCl4 + Ti
Can this work or it's like the CaCl2 way?

runlabrun - 5-1-2005 at 17:38

A few questions:

CaCO3 + Urea --> CaCN2 + CO2 + 2H2O
at what temperature does this take place?
and -->
CaCN2 + 6HCl --> CaCl2 + CCl4 + 2NH3
this was said to occur at elevated temperatures.... how elevated?

-rlr

garage chemist - 5-1-2005 at 17:44

BromicAcid, you said that CHCl3 reacts with KOH? What products are formed? I never heard of such a reaction before...
I know that simple Alkyl halides are hydrolysed to the corresponding Alcohol, but I also know that compounds with more than one OH- group on one carbon atom (an example: carbonic acid, H2CO3) are very unstable.

Mendeleev - 5-1-2005 at 19:32

All these syntheses seem to complicated or requiring weird materials (example: TiCl4). I believe, however, that one can purchase carbon tetrachloride from a dry cleaner or a place that supplies dry cleaners, that's what they use to remove grease.

S.C. Wack - 5-1-2005 at 19:58

No, it really is hard to find, cheap at least.

http://www.google.com/search?hl=en&lr=&q=%22carbon+t...

JohnWW - 5-1-2005 at 20:51

CCl4 was formerly used extensively as a commercial dry cleaning fluid, and in reusable fire extinguishers for fires of inflammable liquids, but was abandoned because of alleged liver toxicity, and also because of its effect on the ozone layer. 1,1,1-trichloroethane is now the liquid of choice in dry cleaning (also used for thinning correcting fluid), but frankly I doubt that it is significantly less toxic or damaging to the ozone layer than CCl4. For reusable fire extinguishers, compressed liquid CO2 (which does not affect the ozone layer) or compressed liquid BCF (bromochlorofluoromethane, which still affects the ozone layer), both of which are gases at ordinary temperatures and pressures, are now used.

BromicAcid - 6-1-2005 at 06:13

Quote:
CaCO3 + Urea --> CaCN2 + CO2 + 2H2O
at what temperature does this take place?


Not sure but it's pretty high (~800C ?), I think this is brought up in the preparation of cyanides thread.
Quote:
CaCN2 + 6HCl --> CaCl2 + CCl4 + 2NH3
this was said to occur at elevated temperatures.... how elevated?


Again, no clue, earlier in the thread when I referenced this I quoted all the information that I found word for word, it's not much to go on, I would think that calcium cyanimide, which will react with water at room temperature, would be reactive enough with HCl and volitize off the CCl4 formed at temperatures as low as 100C.
Quote:
BromicAcid, you said that CHCl3 reacts with KOH? What products are formed?


Chlorobutanol for one, there is a whole thread on it, there are a number of other products formed too, potassium formate among them, it depends on what else is present, water, acetone, or just straight CHCl3, although I don't know exactly what each of these situations will make.

BromicAcid - 13-3-2005 at 10:57

My procedure today. 260 ml 10% NaOCl [.377 mol] was put into a 500 ml reagent bottle with 24/40 glass stopper. To this was added 5.5 ml acetone [.125 mol] and the reaction mixture stoppered and allowed to run for one hour at ambient temperature [-2.5 C]. After which the amount of chloroform in the bottom of the vessel was measured and found to be 5.0 ml. Normally 0.85 g CHCl3 is soluble in 100 ml water corresponding to 2.2 g [~1.5 ml] however solubility decreases with temp and I would guess there is only 1.1 ml or so left in solution.

37 g Ca(OCl)2 was added to the solution along with 10 drops commercial I2 solution for cuts composed of potassium iodide, free iodide and ethanol. The mixture was shaken and took on a white color. Five ml HCl was added which was accompanied by significant evolution of Cl2, the mixture was immediately capped and shaken and the stopper was very difficult to remove due to the solvation of the Cl2 thus liberated and the vacuum produced. This procedure was repeated until 50 ml 28% HCl solution was added. The mixture ended up as a cream color which maintained a slight coloring of Cl2 gas above the solution. The mixture was allowed to react for one hour (in the sun) throughout which time the mixture bubbled.

Now, while I wait for it to complete, my methodology here is that Chlorine + Iodine even in water produces ICl which reacts with CHCl3 to produce HCl and I2 and CCl4. So, iodine was added as a catalyst to the solution left over from chloroform production with the chloroform at the bottom. And calcium hypochlorite was added to produce the Cl2 insitu. The reaction should progressively get more acidic to as the actual reaction produces HCl. So HCl was added to make the solution definitely acidic and the reaction allowed to progress. The boiling point will be the main test, but also due to the decreased solubility of CCl4 and increased weight there should be a noticeably larger amount, e.g., if I had 4.5 ml CHCl3 @ 25C in this mixture, I should end up with 7.45 ml CCl4 at the end, so today that will be my indication that this reaction is running well. If my final yield of non-aqueous liquid is over 7 ml.

I just went out to check on it, it's been 20 minutes. The solution was almost pink and clear. A layer of precipitate mixed with organics had settled to the bottom. So I shook it thinking that magnetic stirring would have helped about now. This caused massive gas evolution and blew the top off almost causing me to loose the contents. Note that when I shook it last it created a vacuum inside the container and no more Cl2 was generated, this time the gas was most definitely Cl2 again. So I would say the reaction is definitely progressing.

As of an hour and a half into the reaction thick oily yellow/green drops have taken to collecting on the surface and suddenly dropping to the bottom. I am left wondering how much of my product may have left the reaction vessel when the top popped awhile ago. The sedimentation is now distinctly floating on top of the organic layer at the bottom. The reaction continues to progress with the evolution of gas.

An Update to come upon completion.

I found a reference the other day for yet another method to make CCl4, passing COCl2 over heated activated carbon produces a mixture of CO2 and CCl4.

[Edited on 3/13/2005 by BromicAcid]

Hmmm!

chloric1 - 13-3-2005 at 12:40

So, you didn't even separate the CHCl3 before catalytic chlorination? Interesting to see what this deveolpes into. MAybe the greenish droplets would be white on with a sodium thiosulfate solution washing. Got pictures? I bet it looks really cool:cool:

BromicAcid - 13-3-2005 at 13:05

It's been 3 hours and it's still reacting and making gas and chlorine on shaking. If I leave it the evolution of gasses slacks off significantly and it separates with a layer of precipiate and under that green organic liquid drops. If I shake it the drops cling to the bubbles at the surface and drip back down (see attachement). I'm going to let it go a little while longer, filter it and check yield. I did this all in 'one pot' because carbon tet is less soluble then chloroform by a margin and I was hoping to squeeze a little more yield out of this.

Update: Decided that it had gone on long enough so used a pipette to pull up the liquid at the bottom and filter though glass wool. But the liquid was too hydrophobic. It would not go though the glass wool even if I tried to press it through with a stopper. So, I took the 500 ml flask and cleaned it out and added 200 ml water and dumped the glass wool and liquid on the glass wool into the flask and shook it up. The green liquid became clear and started to sink to the bottom again. Still, I didn't run any tests, just finished up for the day. No clue if it worked or not.

Slow addition of HCl through a sepretory funnel while the contents of the container were under magnetic stirring would have helped immensly.

[Edited on 3/13/2005 by BromicAcid]

beforeshak.jpg - 37kB

chloric1 - 13-3-2005 at 13:43

Well, that organic layer is definately denser than aqueous solutions. At least that is promising. Buy the way CCl4 has an order quite distinctive from chloroform. This maybe one test. Also, CCl4 freezes at -23C. Unfortunately, chloroform was added to carbon tet to lower the freezing point for fire extinguishers. So there may be enough CHCl3 to keep it from freezing at -23C. I will try to think of another test, but right now I am drawing blanks.

Refractive index?

Hermes_Trismegistus - 14-3-2005 at 07:17

I am rather puzzled by the prior methodology, it seems that evolution of chlorine gas and synthesis of water would be all that would be produced by the addition of HCl to a solution of CaOCl.

The problem with getting that last proton off the CHCl3 is the electronegativity of the other three Cl's repulsing (strongly the further addition of another Cl.

But the CHCl3 does want to give away it's proton pretty bad, if you bubbled hot chorine through the chloroform and condensed the resulting liquid....

You do have a bubbler, 24/40 and condensor set right?

Maybe use that CaOCl and HCl to produce the chlorine, and run it through a length of copper pipe with a bunsen burner under it and bubble that into your chloroform using a thermometer inlet as your gasket?

Know what I mean....... jelly-bean?

BromicAcid - 14-3-2005 at 10:55

Well, what I was going for was the insitu production of ICl from the chlorine being produced and the iodine present. ICl reacting readily with CHCl3 to produce carbon tet and the iodine being recycled. Just hoping to do it in a one-pot synthesis and recover some of the solvated CHCl3 while I was at it.

Magpie - 31-1-2006 at 13:50

I have read this thread and it seems that whether or not CCl4 can be made from CHCl3 via free radical addition of chlorine is, so far, inconclusive.

I want to try it with my freshly made CHCl3. I'm planning to bubble chlorine into CHCl3 at about 50C while it is being irradiated with UV light from a halogen bulb (probably about 11,000 candlepower). So, what is the opinion of the forum members. Is this going to work or not, i.e., give me at least a 50% yield? I realize I will likely have to separate the CCl4 from unreacted CHCl3 and byproduct CCl3-CCl3.

garage chemist - 31-1-2006 at 14:38

I am quite sure that it will work. I thought of giving this reaction a try myself, but then I got some CCl4 from somewhere else.

I think the best approach would be to bubble chlorine into refluxing chloroform with irradiation by strong light (UV or halogen floodlight).

For determining the endpoint of the reaction, it would be very convenient to install a thermometer into the flask.
The reaction mix is kept boiling constantly by heating from below while bubbling in the chlorine.
As the CHCl3 reacts and CCl4 accumulates in the mix, the boiling point of the mix will rise, and when the thermometer indicates that the boiling point of the mix is the one of CCl4 the reaction is done. The same is done with benzyl chloride synthese from toluene, I used this method and it worked beautifully!

Fractionation of the product will still need to be done, because of the C2Cl6 (although the amount of this will be very small).

You should wash your chloroform with conc. H2SO4 before the reaction (several times, until the H2SO4 stays clear), to remove acetone residues from its preparation.

S.C. Wack - 31-1-2006 at 15:57

It is listed as the original (1840) preparation and was recommended by Schorlemmer in 1873 as the preferred method, so it has that going for it.

Magpie - 31-1-2006 at 19:59

Thanks garage chemist and S.C. Wack for your helpful input. I will give this a try once I accumulate a little more chloroform and buy a gas dispersion tube with the fritted glass end.

Using reflux sounds better than 50C. Using temperature to monitor the reaction and tell the endpoint is quite clever. ;)

The_Davster - 31-1-2006 at 22:54

I was thinking a while back, and actually posted it as an edit in the nitromethane thread, with no response, but would chloroacetone undergo the haloform rxn to give carbon tetrachloride? Or would you get chloroform and sodium chloroacetate? Or even just simple chloroform and sodium acetate?

I can try it of course as I have a few g of chloroacetone, but I don't really like working with it...And it would be difficult to determine between chloroform and carbon tetrachloride on small scale.

I also came across an old ~25 year old bottle of 'dry cleaner' with no brand name, and not much info beyond 'contains chlorinated solvent' and it smells like chloroform, but a richer, deeper and less sweet smell. Could this be carbon tetrachloride? Carbon tet was the origional drycleaning solvent.... Oh and the bottle is 110 ml with about 15-30 mL left in it.

Magpie - 1-2-2006 at 09:06

I don't know why chloroacetone wouldn't go right to chloroform if treated with Ca(OCl)2 under haloform conditions. But this is just a guess.

I suspect what you have is indeed carbon tet for the reason you have stated. I have a funny (to me) story related to that. I recently called a dry cleaning place to see if they had a pint (250mL) of carbon tetrachloride they could sell me. She said "Oh, we don't use any wild chemicals here we use Perc." Isn't Perc = perchloroethylene? :D I don't think she had ever heard of carbon tet as it's use was likely before her time. I asked if she would sell me a pint of Perc. She said "No, we are not allowed to sell that to individuals." Same old crap. :mad:

Esplosivo - 1-2-2006 at 09:23

Chloroacetone, following a haloform, would probably give the chloroacetic acid salt and chloroform. Infact I have a plan to synthesize chloroacetic acid using this method. The chloroform produce will also be a great byproduct and easy to separate from the ionic products.

I can buy perchloroethylene as a solvents here (they call it Perchloric ethylene (Solvent 509:900)), although I have little interest in it, since I mostly use DCM and chloroform as solvents.

kclo4 - 4-5-2006 at 16:22

well i dont know if this would work... but I think it would

if you took a small amount of NCl3 and added it to a chlorine/chloroform solution, the chloroform might react with it like this:
CHCl3 + NCl3 = CCl4 + NH3

but of course there is chlorine disolved in it, so it would just be turned back into NCl3

would NH4Cl added to a chlorine solution work to make NCl3?

if so it might be added to chlorine/chloroform solution and work just fine

sorry i dont know, if what i am saying is just tottal crap but i am in a hurry ttyl
(if i can i will edit it later but i really got to go right now)

neutrino - 4-5-2006 at 16:48

The first problem here is safety. NCl<sub>3</sub> is a notoriously dangerous substance ready to detonate at the slightest contact with organic material. It can be handled in chlorinated solvents (this is how early research on this compound was conducted), but I'm not sure if chloroform will work. In any case, one speck of dust in the NCl<sub>3</sub> and BANG. It may be safer under more dilution, I don't know.

I'm not saying the chemistry will or will not work, I'm just saying that this would have serious safety concerns.

kclo4 - 6-5-2006 at 12:51

Yes I Know it would be a Safety problem, but I am not saying to have it be at all concentrated, if you took 1drop of NH3 and put it on chloroform/chlorine it should over time convert the chloroform to carbon tetrachloride, so if somone had somthing like 100mls of chloroform just put it in a cool place, like the fridge. Over time it would convert into HCl and CCl4 maybe.

perhaps a small amount of inorganic particles may not to to bad, it would make the NCl3 less stable and there for, it might react faster or somthing but i dont know, it may also just stop any formation of NCl3 and nothing would happen.

Also would this reaction happen NH4Cl + 3Cl2 = NCl3 + 4HCl?
if it did, I could simply add NH4Cl to a chloroform/chlorine mixture.
I am pretty sure that reaction would happen

BromicAcid - 6-5-2006 at 13:27

Nitrogen trichloride is indeed a chlorinating agent but what proof do you have that it efficently affords the conversion of chloroform to carbon tetrachloride? How is it superior to other safer alternatives such as possibly calcium hypochlorite or even sodium hypochlorite, both of which are known to give this conversion but neither of which have been tested noteably...

kclo4 - 6-5-2006 at 20:10

I don't know!!
It was just a suggestion, and if only a small amount is needed I don't think it is dangerous, also if NH4Cl can be used to make the NCl3, its hardly a danger at all IMO

Just add NH4Cl to chloroform/chlorine mix and let sit.


I personally think it would work faster then NaOCl or the like for that it is less stable.

JohnWW - 7-5-2006 at 14:01

Nitrogen trichloride, produced by the reaction of excess Cl2 with NH3 or ammonium salts (lesser amounts result in NH2Cl and NHCl2), is DANGEROUSLY EXPLOSIVE! The French chemist Dulong who discovered it in the 19th century blew himself up with it, and was seriously injured.

neutrino - 7-5-2006 at 17:41

Yes, that point has already been made. Remember, though, that early research on nitrogen trichloride was done in chlorinated solvents because it was found to be stable in these. I’m not sure if chloroform is chlorinated enough to safely dissolve NCl<sub>3</sub>. It may well be, but I still wouldn't take any chances.

leu - 1-3-2007 at 13:24

It's possible to synthesize carbon tetrachloride from acetone and sodium hypochlorite, Robineau and Rollin published this version of the haloform reaction and it was abstracted in Ber 27 Bd 4 396-7 (1894) :P

Attachment: robineau.zip (67kB)
This file has been downloaded 621 times

Sauron - 1-3-2007 at 13:47

Thanks, but all I see are two lines at the bottom of the page, it's a citation concerning carbon tetrahalides, says nothing about acetone and hypohalites. Nothing about mechanism. No details whatsoever, just title, authors, and journal details.

Was this Ber. entry cited in CA? It's intriguing, but only a teaser.

leu - 1-3-2007 at 14:31

Chemical Abstracts didn't begin publication until 1907, replacing Review of American Chemical Research which ran from 1897 to 1906 :D If you could be bothered to look at the second page of the file you will find the rest of the abstract, the original article's citation given is Monit scient 4. ser 8, 341-2 :P

Sauron - 1-3-2007 at 14:57

Ah. Sorry, I did not see any more pages, but that's a DejaVu file and does not scroll. Pardon me.

@leu, have you reduced this to practice yet?

Obviously very handy, if it works. The application to CHCl3 is of course very well known. I have personally only done that for iodoform.

[Edited on 2-3-2007 by Sauron]

Sauron - 4-3-2007 at 07:28

For @gc

Here's the Robineay abstract in pdf since you can't use DjVu at present.

[Edited on 4-3-2007 by Sauron]

Attachment: Robineau396.pdf (140kB)
This file has been downloaded 700 times

garage chemist - 4-3-2007 at 09:28

The procedure described in there is not of much use.
Chloroform is partially converted to CCl4 by the action of NaOCl solution at 40-50°C.
It is stated that some CCl4 is obtained when acetone is added to an excess of NaOCl solution at 40-50°C.
CCl4 is obtained in low yield. Its presence in large amounts of chloroform can be tested for by heating 1ml of the chloroform 7-8h with 20ml 25% NaOH solution in a closed tube at 100°C. CCl4 is not attacked by this procedure and remains as an oil.
Another method to separate it is to stir 1ml of the chloroform with 400ml of a saturated solution of CCl4 in water. Chloroform, being much more soluble in water than CCl4, dissolves and CCl4 again remains as an oil.

The article suggests that Chloroform does react with the NaOCl to produce CCl4, and I think that that the in-situ generation of chloroform from acetone only serves to finely divide it for better reaction. Thus, I would think that stirring premade chloroform with NaOCl soln at 40-50°C will also make some CCl4. This is of course only useful if chloroform is available.

[Edited on 4-3-2007 by garage chemist]

Sauron - 4-3-2007 at 10:12

Thanks. It does not appear that this method is likely to dislodge the chlorination of CS2 and reduction of resulting trichloromethyl sulfenyl chloride with iron filins, anytime soon as the best method of making CCl4.