Jor
National Hazard
Posts: 950
Registered: 21-11-2007
Member Is Offline
Mood: No Mood
|
|
bottle for CCl4
I am going to buy a liter of CCl4, and I am going to take 250mL of it and give the rest to another member of sciencemadness.
I was wondering, would a glas bottle (normal glass, not brown/amber) with a HDPE cap be suitable for storing it. I will use a DURAN bottle? CCl4
doesn't decompose in light, like chloroform does right? Do I need a PTFE liner?
Or aluminium liner?
|
|
|
woelen
Super Administrator
Posts: 7977
Registered: 20-8-2005
Location: Netherlands
Member Is Offline
Mood: interested
|
|
You need a PTFE liner. It does not really attack plastics, but it is absorbed by the plastic. You can see this because the cap of the bottle becomes
somewhat thicker than usual and you can even faintly smell it. I rebottled my redistilled material (appr. 150 ml is left) in a 250 ml bottle.
|
|
|
Jor
National Hazard
Posts: 950
Registered: 21-11-2007
Member Is Offline
Mood: No Mood
|
|
Ok, so it does not diffuse through PTFE?
Is an aluminium liner ok, or some other palstic, as PTFE is expensive...
If it only leaks very slowly, it's no problem. I'm not worried of toxicity anymore, after reading the following:
http://209.85.229.132/search?q=cache:7GBLmWGjAPQJ:www.hpa.org.uk/web/HPAwebFile/HPAweb_C/1235032868795+dangers+carbon+tetrachloride&cd=31&hl=n
l&ct=clnk&gl=nl&client=firefox-a
http://209.85.229.132/search?q=cache:Ykw-Y9g73jcJ:www.hpa.org.uk/web/HPAwebFile/HPAweb_C/1235032869649+10ppm+no+adverse+effects+carbon+tetrachloride&a
mp;cd=2&hl=nl&ct=clnk&gl=nl&client=firefox-a
80ppm for 3-4 hours gives no harmful effects.
250ppm fo 4 hours in some perosns gave no adverse effects, only to an alcoholic who died after 15 minutes.
kidney and liver restore by themselves when exposure is not too high or too long.
CCl4 toxicity, greatly exaggerated.
So soem leaks are not a problem.
[Edited on 16-5-2009 by Jor]
|
|
|
pHzero
Hazard to Self
Posts: 89
Registered: 16-5-2009
Member Is Offline
Mood: Fully substituted
|
|
You can get PTFE sprays in hardware shops. Theyre used to deposit a thin PTFE layer on stuff for lubrication. That might work.
|
|
|
Jor
National Hazard
Posts: 950
Registered: 21-11-2007
Member Is Offline
Mood: No Mood
|
|
Yes, but buying a PTFE spray costs more than a cap for a DURAN bottle with PTFE liner. So i'm looking for alternative materials wich can be safely
used, otherwise I will buy the cap.
|
|
|
Hydragyrum
Hazard to Self
Posts: 62
Registered: 29-4-2009
Member Is Offline
Mood: Curious
|
|
Hmm, I'd be worried that the Al would react with the CCl4 - maybe not immediately, but in time - could lead to carbene formation, and possibly an
explosion! Stick to PTFE.
Chemistry is life (and a whole lot more)
|
|
|
woelen
Super Administrator
Posts: 7977
Registered: 20-8-2005
Location: Netherlands
Member Is Offline
Mood: interested
|
|
Al caps can be used, but the CCl4 must be perfectly dry. If moisture is present, then a reaction can occur, which is very slow. Originally, my CCl4
was stored in a bottle with an Al-coated liner, which also had some plastic coating on the Al to make it more slippery (and more robust and better
closing).
There is no need to fear an explosion. Explosion cannot occur with bulk aluminium, it might be possible with very finely powdered Al, soaked with
moist CCl4, but that is not the situation in your place.
But personally, I would stick to PTFE if you intend to keep a somewhat larger quantity of CCl4 and want to keep it for a longer time.
Btw, why are you so interested in CCl4? Aren't CH2Cl2 and CHCl3 viable alternatives. Both CHCl3 and CH2Cl2 are much easier to obtain and are much
cheaper. CHCl3 can be dehydrated by distillation over P4O10 (not with Na!). I intend to make PBr5 soon from red P and Br2, and I either will use
CH2Br2 or CHCl3 for suspending the red P and drip in bromine diluted in the same solvent. For many synths I think it is OK. With bromine and even with
chlorine, the substitution of H is only marginal if the reaction is carried out in a dimly lit room.
|
|
|
Fleaker
International Hazard
Posts: 1252
Registered: 19-6-2005
Member Is Offline
Mood: nucleophilic
|
|
I REALLY recommend you check out what this seller has to offer and order as many as you think you'll need.
I use the 2L FEP bottles and have been very, very happy with them.
http://shop.ebay.com/merchant/billye46
I have my DCM, CCl3, and CCl4 all in FEP bottles and they work very well. They make black bottles too that are great for red fuming nitric acid.
Neither flask nor beaker.
"Kid, you don't even know just what you don't know. "
--The Dark Lord Sauron
|
|
|
Jor
National Hazard
Posts: 950
Registered: 21-11-2007
Member Is Offline
Mood: No Mood
|
|
Woelen, I need carbon tetrachloride for a few reasons:
-synthesis of CrCl3. I have found out this is still the most attractive method for me. I have done small pilot experiment with CCl4 vapour over Cr2O3
(active, from ammonium dichromate decomp.), and I got some product, although yields were bad. this was because most CrCl3 volatised didn't sublime in
time before it was vented away. I need to find the right glasware, I have been using a CaCl2-drying tube 
The only big problem is the phosgene byproduct, wich i want to destroy, probably with aqeous ethanol or ammonia. I need to find a good U-tube (with a
ground glas joint, so I can attach a tube-adapter), or a relatively long horizontal tube with ground glass joints. i haven't been able to find them
yet.
-Solvent. For some inorganic highly reactives it is supposed to be a good inert solvent. For example, i still want to try the CCl4 extraction of Mn2O7
from the H2SO4 layer, wich was described in literature. I know woelen, that we both did experiments on this, and failed, but I want to give it a try
again, maybe adapting conditions. The only problem is the highly dangerous Mn2O7, so very small scale is preferred.
I doubt DCM would work for Mn2O7. I would imagine it would be readily oxidised to phosgene, with water and MnO2 as byproduct. I think that CHCl3 would
also be unsuitable, considering that even CrO3 will oxidise it at the boiling point of chloroform to phosgene.
-Trying some reactions on small scale with reactive metals.
-And another final reason is that it is very expensive, and i can get it for a really good price now (35 EUR, 1L). And besides, it might be completely
unavailable in the future, because of Montreal Protecol, and it's extremely exaggerated toxicity. CCl4 is really not that toxic, unless you have drunk
alcohol or suffer from chronic alcoholism. In that case, CCl4 can match NO2 acute toxicity (an alcohist died after 15 minutes 250ppm, while healthy
persons with no alcohol in blood had only a slight headache after 4 hours 250ppm!). Just read all the articles available on the toxicity studies,
facts don't lie. Not saying it is not a toxic chemical, but compared to other nasties it is ofter greatly overrated.
And after all, I just take 250mL!
And finally i already have a liter for DCM (bought it because could have it for cheap, 10 EUR for 1L), and didn't see added hazards in keeping it
around. I also have some CCl4 and CHCl3, 30ml former and 70mL latter, both from woelen 
I might buy some chloroform, our supplier has bottles from an old lab, and he is willing to pour 100-250ml from them in seperate bottles.
Indeed Fleaker, those seem to be nice prices, for good bottles. However, they don't ship to the Netherlands. Also, I can get DURAN glass bottles with
red PTFE lined caps, for about 8-10EUR (depending on size). More expensive, but no shipping costs (my supplier always delivers personally.
|
|
|
vulture
Forum Gatekeeper
Posts: 3330
Registered: 25-5-2002
Location: France
Member Is Offline
Mood: No Mood
|
|
| Quote: |
I might buy some chloroform, our supplier has bottles from an old lab, and he is willing to pour 100-250ml from them in seperate bottles.
|
You might want to check that chloroform before using it, it has a limited shelf life.
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
|
|
|
woelen
Super Administrator
Posts: 7977
Registered: 20-8-2005
Location: Netherlands
Member Is Offline
Mood: interested
|
|
Vulture, that's new to me. What is happening to chloroform, when it is stored in a well-sealed bottle? I also have a very old bottle of chloroform,
appr. 350 ml left, a reagent grade bottle from Merck, most likely 20 years old or so, but still in perfect condition.
Does CCl4 or CH2Cl2 suffer from the same problem as CHCl3?
I always had the impression that CHCl3 can be stored indefinitely, as long as no moisture or oxygen is allowed to come into contact with the liquid. I
can imagine that old CHCl3 might need to be distilled before use, but that is the case for many organic solvents, especially the somewhat older ones.
I read two MSDS's and they both tell that chloroform is stable, provided it is stored in dark bottles:
http://www.sciencelab.com/xMSDS-Chloroform-9927133
[Edited on 18-5-09 by woelen]
|
|
|
Jor
National Hazard
Posts: 950
Registered: 21-11-2007
Member Is Offline
Mood: No Mood
|
|
I was wondering as well...
I knew chloroform was oxidised to phosgene, wich reacts with the stabiliser (EtOH) to diethyl carbonate ( EtOC(=O)OEt). I can imagine that at some
point all ethanol will be consumed, and fosgene will be in the bottle, but how would chloroform itself be unstable? Decomposition to HCl, Cl2 and C?
|
|
|
Hydragyrum
Hazard to Self
Posts: 62
Registered: 29-4-2009
Member Is Offline
Mood: Curious
|
|
Chloroform can decompose when exposed to light (as can CCl4 I believe - the driving force is relief of crowding around the carbon). You can store
CHCl3 over anhydrous K2CO3 to soak up the HCl produced.
DCM is much more stable, and incidently DCM is apparently much less toxic too (or so I have been led to believe) than either CHCl3 or CCl4. Always use
DCM unless you specifically need the others.
Chemistry is life (and a whole lot more)
|
|
|
panziandi
Hazard to Others
Posts: 490
Registered: 3-10-2006
Location: UK
Member Is Offline
Mood: Bored
|
|
Jor... You are going to risk using halomethanes? I'm quite shocked... I mean the *scare* of carcinogenicity I would have thought to put you off?
If I was going to bottle CCl4 I would opt for a dark amber bottle, with a sturdy black bakelite lid and a teflon liner. Much like an old Winchester
bottle. Failing that I would opt for a Fisherbrand Winchester with the blue plastic lids and teflon liner. Finally failing that option a clear Schott
Duran bottle with teflon liner and stored in the cool and dark.
Sometimes CCl4 is the prefered solvent or reagent of choice, and it is such a shame it is terrible to get hold of. Certainly for many purposes CH2Cl2
and CHCl3 are convenient and cheaper alternatives but as Jor states, sometimes CCl4 is the only suitable compound. Similar to CS2 in that respect
(something that you can often replace, but when it really calls for it there is no alternative!)
Good luck Jor.
p.s. I wouldn't ever opt for aluminium caps or aluminium film lined caps, especially for chlorinated solvents. Judst because I'm picky.
|
|
|
woelen
Super Administrator
Posts: 7977
Registered: 20-8-2005
Location: Netherlands
Member Is Offline
Mood: interested
|
|
Are you sure this is safe? This leads
to pressure buildup
K2CO3 + HCl --> KCl + KHCO3
KHCO3 + HCl --> KCl + H2O + CO2
The CO2 gas cannot escape and will result in pressure buildup, certainly if a considerable part of the K2CO3 already has been converted to KHCO3.
Besides that, CHCl3 reacts with bases, I'm not sure what happens with K2CO3 and if that is a sufficiently strong base. Personally, I would not do add
anything at all and just keep it well sealed when it is stored.
|
|
|
Hydragyrum
Hazard to Self
Posts: 62
Registered: 29-4-2009
Member Is Offline
Mood: Curious
|
|
There are only trace amounts of HCl formed (only a small amount of KHCO3 will be formed, with still the bulk remaining as K2CO3) - if major
decomposition of chloroform occurs (which apparently can happen in rare cases, perhaps when it's in contact with Al foil for example?) then CO2
build-up will be the least of your worries.
We used to keep our CDCl3 (for NMR) over K2CO3 and we never ever had a problem; it absorbs water, HCl, and removes COCl2 as well (the other
byproduct). Perhaps if you're going to store the chloroform for long periods then crack open the cap every few weeks to release any pressure - but you
should do this anyway in case it is building up HCl pressure!
I've also seen Ag metal foil used, presumably removes Cl as AgCl and perhaps produces the same with COCl2.
What it boils down to is this: use CH2Cl2 everytime unless you have a specific reason for using CHCl3 or CCl4 (apparently you get much slower liver
damage with CH2Cl2 as well).
[Edited on 21-5-2009 by Hydragyrum]
Chemistry is life (and a whole lot more)
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
