| Pages:
1
2 |
woelen
Super Administrator
Posts: 7977
Registered: 20-8-2005
Location: Netherlands
Member Is Offline
Mood: interested
|
|
Jor, weren't you afraid of cracking test tubes? A very hot test tube on which a cold liquid is dripped is begging for cracks! I always feel scary when
working with very hot test tubes. A crack can have nasty consequences and it at least leads to bad spots on the work bench.
But the experiment sounds interesting. The fact that you obtained purple CrCl3 is a good thing. It really surprises me that you do not need a red
heat.
You could try the experiment with stronger heating, putting some CrCl3.6H2O in the middle, putting some cotton wads, soacked with CCl4 at the bottom
of a test tube end and then strongly heating the CrCl3.xH2O. The test tube must be kept almnost horizontally, but slightly tilted, such that the wads
with CCl4 are somewhat higher than the CrCl3.xH2O. The open end must be stoppered LOOSELY with a cork or a dash of glass wool.
When you strongly heat the CrCl3.xH2O, then the heat which goes along the test tube will be sufficient to slowly evaporate away the CCl4 and that will
lead to a continuous stream of CCl4 over the CrCl3.xH2O, which is almost free of air.
|
|
|
DJF90
International Hazard
Posts: 2266
Registered: 15-12-2007
Location: At the bench
Member Is Offline
Mood: No Mood
|
|
I found an article regarding the tetrahydrofuranate (didnt realise benzylchloride1 had already mentioned it  ) that I thought I would share. It'll give you something nice to do with your anhydrous CrCl3, and will also enable
you to make organometallic complexes (as the article suggests). Now, in my honest oppinion I find complex chemistry quite boring, but to see some
triphenylchromium complex... well that might just convert me 
Attachment: Chromium trichloride tetrahydrofuranate.pdf (142kB)
This file has been downloaded 836 times
|
|
|
benzylchloride1
Hazard to Others
Posts: 299
Registered: 16-3-2007
Member Is Offline
Mood: Pushing the envelope of synthetic chemistry in one's basement
|
|
I found an old Pyrene fire extinguisher, disassembled it, pipetted out the crude carbon tetrachloride and redistilled it. I obtained 299g of carbon
tetrachloride from the half filled fire extinguisher. Now I have enough to conduct many organic and inorganic experiments that I have been putting off
because this reagent has been unavailable.
Amateur NMR spectroscopist
|
|
|
Jor
National Hazard
Posts: 950
Registered: 21-11-2007
Member Is Offline
Mood: No Mood
|
|
Nice! I made a topic before that old extinguishers might be a good source for peope trying to find CCl4. Good job, I'd like to hear your results.
|
|
|
benzylchloride1
Hazard to Others
Posts: 299
Registered: 16-3-2007
Member Is Offline
Mood: Pushing the envelope of synthetic chemistry in one's basement
|
|
The carbon tetrachloride has a slight carbon disulfide like smell, as it is probably old enough to have been derived from the chlorination of carbon
disulfide. I should redistill it from potassium hydroxide to remove the carbon disulfide and collect a narrow fraction; some material boiled below
60C. Most of the material distilled between 65-68 C. The low boiling point is due to the laboratory's high elevation location.
Amateur NMR spectroscopist
|
|
|
Jor
National Hazard
Posts: 950
Registered: 21-11-2007
Member Is Offline
Mood: No Mood
|
|
As I have plenty CCl4 now (ca. 300mL) I decided to give the CrCl3 synthesis another go. I probably evaporated the CCl4 too fast and a lot of it got
out unreacted. Therefore after one run I had a still impure product, but after the second run with the crude material, I got a product wich contains
only very small amounts of green solid, and is probably about 98% pure. It can be further purified by subliming in chlorine atmosphere at 700C. That
is when you obtain the nice metallic like purple crystals.
Pictures are here:
http://www.amateurchemie.nl/viewtopic.php?f=20&t=299
|
|
|
12AX7
Post Harlot
Posts: 4803
Registered: 8-3-2005
Location: oscillating
Member Is Offline
Mood: informative
|
|
Pretty! So few compounds are purple.
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
Very interesting indeed. Look forward to a report on the sublimation of the anhydrous chloride in Cl2. Might sublimation in dry HCl not be slightly
less dangerous?
I made some anhydrous MnCl using the NH4Cl sublimation method. I wonder if hydrated MnCl2 can be converted to anhydrous MnCl2 using your CCl4
method...
I've read about using CCl4 as a chlorinating agent for anhydrous oxides but have never come across this particular method.
Well done.
|
|
|
benzylchloride1
Hazard to Others
Posts: 299
Registered: 16-3-2007
Member Is Offline
Mood: Pushing the envelope of synthetic chemistry in one's basement
|
|
A break through has been made in the synthesis of anhydrous chromium (III) chloride by the lab of Benzyl Chloride1. i was reading Inorganic synthesis
volume 5 and there is a procedure for the synthesis of uranium (III) chloride from uranium oxide and hexachloropropene yielding UCl3 and
trichloroacryloyl chloride. Hexachloropropene can be made by treating unsymmetical heptachloropropane with KOH. The heptachloropropane can be made
from chloroform and tetrachloroethylene using a aluminum chloride catalyst. The procedure can be found in Organic Synthesis Collective volume II. From
my experiments, chromium (III) chloride can be made by refluxing heptachloropropane with the hydrated salt producing the purple anhydrous chloride. I
would not be suprised if any compound with a trichloromethyl group could be used for this experiment; benzotrichloride or possible hexachloroethane,
available in large quantities cheaply from the internet. Now CrCl3 is available to any one with a hood and a few common chemicals. If one was to make
hexachloropropene and use this for the dehydration of metal chlorides, the acid chloride could be recovered and used to produce acid chlorides of
lower boiling point. Two useful reagnets out of one reaction. Just a theory; oxalyl chloride from hexachloroethane???
Amateur NMR spectroscopist
|
|
|
Magpie
lab constructor
Posts: 5939
Registered: 1-11-2003
Location: USA
Member Is Offline
Mood: Chemistry: the subtle science.
|
|
Nice work. I'm happy to hear of this as I know that I will be wanting some CrCl3 some day to prepare pyridine:CrCl3 for the production of aldehydes.
When I looked to buy some CrCl3 the price and the hazmat fees made it prohibitive.
That's a good theory about being able to produce lower bp acid chlorides too. I wish Sauron were here to comment on this.
The single most important condition for a successful synthesis is good mixing - Nicodem
|
|
|
benzylchloride1
Hazard to Others
Posts: 299
Registered: 16-3-2007
Member Is Offline
Mood: Pushing the envelope of synthetic chemistry in one's basement
|
|
Magpie, what you are talking about is pyridinium chlorochromate whic is made from chromium trioxide, not CrCl3. Chromium trioxide can be made by
treating potassium dichromate with concentrated sulfuric acid, chilling and filtering the red crystals of the trioxide off with a sintered funnel. The
procedure can be found in one of the inorganic lab books available in the Sciencemadness Library.
Amateur NMR spectroscopist
|
|
|
Magpie
lab constructor
Posts: 5939
Registered: 1-11-2003
Location: USA
Member Is Offline
Mood: Chemistry: the subtle science.
|
|
Ah...thanks for the correction. I should have caught that Cr+3 wouldn't be much of an oxidizer. 
The single most important condition for a successful synthesis is good mixing - Nicodem
|
|
|
| Pages:
1
2 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
