tsathoggua1
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ICl and ICl3
Alright, so I have been preparing these two interhalogen compounds. Iodine monochloride and a small amount of iodine trichloride, possibly dissolved
in the monochloride and soaked into some of the CaCl2 (anhydrous) that is being used as dessicant. The setup is a chlorine generator and passing dried
Cl2 gas through elemental iodine crystals. The reaction seems to be working just fine. Indeed its got to be one of the better looking, more
attractive visually, reactions I've done, in that it has formed a mixture of liquid-phase and alpha-ICl in the receiver, ICl3 is confined to the point
where the Cl2 first hits the I2. There is a small piece of steel woool just behind the dessicant, yes, I know it will react and corrode the Fe to
FeCl3 but its just sufficient a tuft to stop any CaCl2 falling back into the generator.
From the first condenser, loaded with CaCl2, chlorine gas passes through a second, longer condenser (both liebigs) in line with the first. Then the
liquid ICl drips into a collection flask.
It is stated in datasheets to react violently with metals. Are powdered metals meant here, or can it be transferred safely with a cannula via glass
syringe into glass ampoules? Or is a violent reaction possible with a simple steel needle in the time that it takes for the monochloride to pass
through the needle into an argon-filled ampoule ready for sealing.
The system itself is closed well, and transfer will be direct from receiver into glass bottle, and then into a more chemically resistant glass bottle
to store the bulk of it (the iodine is unweighed but there should be a good few oz, I am going by chlorine and the difference in character between the
mono and trichloride.) The secondary receiver will be precooled with dimethyl ether/diethylene glycol/ice/salt mixture and any vapor led into a trap
to prevent any suckback followed by passage into sodium carbonate, and the amp likewise cooled using MeOMe and pre-purged via addition of argon via
cannula.
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woelen
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Yes, ICl and ICl3 are quite interesting compounds.
They are very reactive. Do not bring them in contact with metals. With bulk metal you will not have explosions or fire, but these compounds will
corrode the metals and will become severely contaminated. Use all glass to transfer them to ampoules. ICl can be gently heated to 50C or so to make it
a mobile liquid which can be poured.
ICl is a dark brown compound with brown vapor. It resembles bromine, but it is less red. It can remain liquid for a long time in a cold room, but
eventually it solidifies to a dark brown, nearly black solid.
ICl3 is a bright orange solid in the bulk state, in finely powdered form it is yellow. I myself made an ampoule with a little I2 inside and I passed
over dry Cl2 until all I2 was converted to yellow ICl3 (which covered the glass of a large part of the ampoule). Then I put in extra Cl2 so that I
have an atmosphere of nearly pure Cl2 and then I sealed the ampoule. Over the days I observed that the ICl3 evaporated slowly and settled again on the
bottom. The ampoule was standing upright on a cold wooden bench. Now, the bottom is covered by a bright orange crust and above that there is a
yellow/green atmosphere of Cl2.
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tsathoggua1
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Yes it hydrolyses pretty quickly if allowed to and its a bugger for penetrating stuff like tubing too. Just got to strip some metadata first and will
post some pics and stuff.
At first, I thought I'd fucked it (reversibly) after addition of a last portion of Cl2. But had left it overnight with the vapor open to excess I2.
Its formed a central lake of liquid with some great looking crystals Some ICl3 is present, mostly where the Cl2 first entered the column containing
I2.
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tsathoggua1
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Question-will Dow-Corning vag grease stand up to ICl and ICl3? the former is the more important, and more prevalent product by far, neat, in a flask?
Its going to have to wait to be transferred to a longer term container since the weather is abysmal atm.
The plan if so is to give the stoppers a layer of teflon tape, some high-vac grease either side of the layers to plug up the flask temporarily.
Its murder on keck clips too.
Edit-went with a combination of a layer of high-vac grease on the stoppers of the flask, wrapping in teflon tape windings then giving it another
smearing of vac grease. Hopefully it'll hold up better than the keck clips. Going to get some metal ones and electroplate them for my interhalogen
experiments.
Anybody have suggestions or know which metals or alloys can resist or are impervious (and to what degree) ICl, ICl3, iodine and chlorine bromides?
does iridium stand up to ICl or ICl3 in the cold or at distillation temperatures? I know Ir metal is attacked by Cl2 at elevated temperatures, but
presumably this being iridium 'elevated' means very significantly so.
[Edited on 22-3-2017 by tsathoggua1]
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woelen
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For long term storage I only see glass as an option. Even teflon does not work well. The brown stuff slowly is absorbed by the teflon and in the long
run, it escapes through the teflon. For distillation, you also only can use glass. Grease dissolves in ICl and slowly is attacked.
ICl3 is even more difficult. It is a solid and easily decomposes to ICl and Cl2. You really have to store it under an atmosphere of Cl2.
Interestingly, ICl3 is insoluble in alkanes (e.g. in heptane or in a mix like ligroin) and also in CCl4. I did an experiment by dissolving I2 in
heptane. Then I bubbled Cl2 through this. The liquid first turns brown (formation of ICl). Next, it becomes turbid and a yellow/orange solid
precipitates. This must be ICl3.
Maybe in solid ICl3 the material exists as ionic compound. This would explain insolubility in non-polar solvents and also the fact that it sublimes
and decomposes instead of becoming liquid on heating. A similar effect exists for PCl5. In the solid state this exists as PCl4(+)/PCl6(-). Maybe the
same is true for ICl3, existing as dimers I2Cl6, which internally are mostly ionic ICl2(+)/ICl4(-)? Wikipedia mentions the existence of I2Cl6 and also
talks about the equilibrium between I2Cl6 and ICl2(+) + ICl4(-). Anyway, ICl3 is quite interesting, in my opinion even more so than ICl.
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tsathoggua1
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That insolubility really does surprise me, that it does not dissolve in carbon tet.
I've done the halogenation, a good method seems to be to perform it (when synthesizing the monochloride) and passing Cl2 until the first hint of ICl3
is formed. Then in a closed system, use a little excess iodine in the condenser and leave it overnight, although with the Cl2 generator still attached
but no longer either passing a current of Cl2 through CaCl2 to first, dry it and then to leave it overnight.
For the amp, a thick-walled borosilicate boiling tube of about a foot long is being prepared. The filth trashed my lab, and whilst a portion will be
separated from the majority and stored in a glass bottle with a chemically resistant cap (that is known to have stored a quantity of ICl for many
months without any signs of penetration, for some to be available when wanted, and the entire lot not need to be used at once and the rest is being
sealed in glass. A pig deliberately, amongst other items, broke this, damaged it by putting a hole in the bottom at the very end. Once the ground
glass-jointed end is sealed and fused shut
until suchtime as it is to be used in a reaction. Then the
remainder bottled, so as to investigate its reactivity with various substrates now. But most of it will be sealed up.
I have a question-when fusing the tube shut (I have a torch that will do the job, will let it cool very slowly after annealing the hot, unfilled amp
in the making, gradually ramping the temperature down to room temperature, fill the amp and freeze the contents solid under dry argon. Once ready to
be finally sealed at the end used to transfer the reagent, then the end far from the reagent in solid form will be fused shut, keeping the other under
an ice-salt-ethylene glycol/H2O bath.
For the ground glass seal, wouldn't some potassium silicate solution (80%) used as though it were lubricant assist in forming a good seal? apply,
stopper, gently bake dry and then once the water is gone then start with the torch? Needless to say this is an outside job, the fumes from ICl are
rather virulent to say the very least, and enough to make one's eyes sting from a room in the outbuilding behind several inches of doorway, whilst
wearing goggles, gas mask and full face shield. The building is being vented out completely, and the reagent itself frozen solid using
ice/salt/ethylene glycol/H2O whilst doing so in order to minimize lossess of any iodine monochloride in the gaseous phase.
So my question is this-use the potassium silicate solution or don't use any, and simply use the torch alone?
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tsathoggua1
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Looks like I might not have to keep it in an amp after all, found some old evidence bottles from a pig raid in the past, and one of them had a small
sample of ICl in it from a synthesis on a microscale a long time ago, and its proved completely impervious to it. Stupid fucks came, trashed the
place, 'took samples' of various chemicals and then just left them on the benchtop. Whatever the caps are made of is pretty tough stuff and will
contain some rather nasty reagents
Got to strip the metadata from the videos then will upload them somewhere.
Edit-here we go. End product, unsurprisingly, its remarkably dense, I didn't measure it volumetrically, but there is around 3 1/2-3 3/4 oz here in
this bottle. Total time taken for synthesis around three days (could have done it faster but access to workspace was limited chronologically and was
of course, something that had to be conducted with great care, for this is not a reagent that is too likely to give one a warning nip if there is any
screwing up.
[Edited on 24-3-2017 by tsathoggua1]
 
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tsathoggua1
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Woelen, ICl seems like its interesting enough to begin with.
It will for example add to a double bond, unsurprisingly, like homomeric diatomic halogens, only to yield an iodochloride. And whilst I am trying
currently to remember what it is, there is at least one catalytic system that will selectively dehalogenate an iodide in the presence of chloride.
Plus it should allow for some decent potential for kinetically controlled reactions involving nucleophilic substitutions.
The column I used for the synthesis of the ICl, plus the flask it dripped into once synthesized and condensed from the vapor phase actually originally
ended up as much ICl3, my answer to this was to leave it overnight for the vapor to react with excess I2, simply by using excess as condenser packing
and allowing the ICl3 to revert back to ICl overnight and return to the flask. Theres a fair bit still unreacted, so that I shall chlorinate further
to produce some ICl3 to experiment with.
I see relatively few interhalogen-related threads on the forum, perhaps its time for these interesting compounds to be further explored. ICl3 is the
furthest chlorinated of the iodine chlorides is it not?
Reference exists on wikipedia to bromine monochloride oxidizing Hg(I) to Hg(II). Will iodine monochloride serve to prepare either the divalent
chloride or iodide of mercury? Or a mixed iodochloride? from mercury subsulfate, or mercury sulfide/selenide/tellurides ?
Who wants to suggest some experiments to do with ICl and/or ICl3?
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CuReUS
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Quote: Originally posted by tsathoggua1  | | And whilst I am trying currently to remember what it is, there is at least one catalytic system that will selectively dehalogenate an iodide in the
presence of chloride. |
you could try using acetone-http://www.sciencemadness.org/talk/viewthread.php?tid=66322
another way could be to convert the iodo into a grignard(I reacts faster than Cl) then hydrolyse
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tsathoggua1
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Just a minor update-Dow-Corning high-vac grease is a temporary measure. It definitely needed the teflon tape wrapped round the stoppers and greased
both before and after PTFE tape winding however. On a non-PTFE-wrapped connection though, exposed grease rotted away into some sort of crumbly
polymer-like material.
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