Sciencemadness Discussion Board

Anhydrous Aluminum Chloride prepration

Chainhit222 - 26-7-2010 at 15:22

I just made anhydrous aluminum chloride. You will need:

-aluminum foil
-a barby
-chlorine or hcl gas source
-a piece of metal pipe (i used copper)
-some way to connect it all together (i afro rigged it)

my setup was:
1) flask connected to a addition funnel (ground glass 24/40)
2) a hose (i used tygon, vinyl is fine) leading from the hose barb on the flask to a ground glass vacuum take off thing wrapped in electrical tape and wedged into a copper tube filled with aluminum foil from the food store laid across the barby
3) a liebig condenser cooled with room temp water with one end wrapped in electrical tape wedged into the end of the pipe

I preheated the barby as high as it would go (seems to be like 450c) (take off the flame guard if it has one) and then laid the pipe on it. At this point the pipe was being flooded with argon gas so the aluminum would not oxidize (i dont think it was necessary, but why not if you got a tank). After I was confident that the pipe and reactants were hot enough I switched the hose from argon to the hcl gas generator and turned it on.

AlCl3 began to sublime and condense in the liebig. Once I ran out of hcl gas I took the liebig off and put it over a container. I then took a clean plastic glassware brush and pushed/twisted it through the liebig, which caused the alcl3 to fall out into my container. Id recommend a large chlorine gas generator, I ran out of chlorine so I just got a few grams of AlCl3 which is very slightly contaminated with burnt electrical tape.

If you actually wanna do this, I would recommend adding a drying tube for the chlorine or HCl gas, and using some kind of heat resistant material (maybe muffler tape?) to make a connection between your glassware and the copper pipe.

http://img807.imageshack.us/img807/241/thugfurnace.jpg (picture of setup)
http://www.youtube.com/watch?v=bpi7cX5d0iw (youtube video of reaction)

Why not use a quarts tube you ask? Because I cannot afford a quarts tube or a tube furnace. I have 12$ in my wallet.

[Edited on 26-7-2010 by Chainhit222]

[Edited on 26-7-2010 by Chainhit222]

12AX7 - 26-7-2010 at 15:34

Why does it not form CuCl2?

Chainhit222 - 26-7-2010 at 15:43

Quote: Originally posted by 12AX7  
Why does it not form CuCl2?


Because its subliming away, the melting point of CuCl2 is 500c, so I suppose its plausible that there could be a bit of cucl2 contamination. The AlCl3 sublimes at 200c, way before the CuCl2 even melts.

Not to mention it would turn water blue if it was contaminated with CuCl2 (and it did not seem to do so in my test). Not to mention you can vacuum sublime the AlCl3 to purify it if you want to :)

Additionally you can easily use a thin steel pipe (like say a broom stick) instead.



****************************
copper does not react with HCl :P
****************************

[Edited on 26-7-2010 by Chainhit222]

12AX7 - 27-7-2010 at 13:48

Ok, so if nothing else, you're doing thermal seperation. Like distilling TiCl4 from FeCl3 and etc. That works, and as a bonus, aluminum reacts with CuCl2 and most others, so if you have an excess of metal, you should get excellent results.

Does steel passivate to hot HCl? FeCl3 is more volatile, though still not as much as AlCl3. Not that that's a big deal, most of the time AlCl3 and FeCl3 can be substituted as Lewis acids.

If used as a long-term apparatus, I wonder if there would be any erosion of the pipe (steel or copper). Meh, can probably get more than a few pounds of AlCl3 out of it by then.

Tim

Chainhit222 - 27-7-2010 at 14:22

Quote: Originally posted by 12AX7  
Ok, so if nothing else, you're doing thermal seperation. Like distilling TiCl4 from FeCl3 and etc. That works, and as a bonus, aluminum reacts with CuCl2 and most others, so if you have an excess of metal, you should get excellent results.

Does steel passivate to hot HCl? FeCl3 is more volatile, though still not as much as AlCl3. Not that that's a big deal, most of the time AlCl3 and FeCl3 can be substituted as Lewis acids.

If used as a long-term apparatus, I wonder if there would be any erosion of the pipe (steel or copper). Meh, can probably get more than a few pounds of AlCl3 out of it by then.

Tim


im gonna try this with a piece of steel fence post in a little bit, gonna use tightly wrapped aluminum foil to make the glass fit. I will put a bit of vac grease on the end which will not be hot too.

[Edited on 27-7-2010 by Chainhit222]

peach - 27-7-2010 at 14:42

Yars could just be usin' a piece o' glass if contamination be an issue. Doesn't even need to be ground.

Crack open the yellow pages, or your proximal equivalent, and look for neon signs. Then call them all and ask if they could sell you a bit of borosilicate tubing.

In terms of demethylations, it won't matter much if you have contaminant FeCl3 in there, as it'll act as a Lewis acid as well, as me valve lovin' salt be pointin' out already.

But, if you be lookin' at me own thread on a DCM based method, yar be seein' some horrible brown shit be coatin' me commercial acid. Iron contamination in yar AlCl3 be givin' her a yellow tint, which be similar to slightly hydrated AlCl3. Hydration o' the acid yields B/L acids, which be alterin' the properties o' the Lewis acid with regards to some things, so the pure white colour be a good assurance of yar startin' reagents and something yar should be aftar.... Ar....

I still be unsure of what that brown on me commercial grade be and suspect it be some form of Iron compound. And she be causin' havoc with potential tar producin' results, as it be lookin' identical.

[Edited on 27-7-2010 by peach]

Chainhit222 - 27-7-2010 at 16:52

fence post = mad fecl3 contamination, its no good. The way to go is copper pipe + hcl generated from h2so4/nacl or h2so4/cacl2

if you use copper pipe then the product is fairly pure. I am going to resublime it as soon as i drill this stopper. I recommend a 400mm liebig to cool, the 20cm aint doing a good enough job, i was running around my yard with a leaf blower in a gas mask shooing clouds of alcl3 away so my neighbors would not get suspicious if the cloud traveled into their yard :x
I hope they did not see me


btw peach, what is your aluminum from, is it pyrotechnic aluminum by any chance? If so, that stuff is coated to prevent reactivity.



wow, vacuum sublimation is such fucking bullshit. I never imagined it would be such a long boring inefficient process, my god.

[Edited on 28-7-2010 by Chainhit222]

mr.crow - 27-7-2010 at 17:52

You guys are crazy

I have a mental image of chainhit's Thug Furnace smoking away and him running around frantically with a gas mask and leaf blower.

I always thought the hard part would be to get the sublimed fumes to condense properly and into a container.

Chainhit222 - 27-7-2010 at 18:03

Im just gonna condense it into a frederichs condenser and then wash it out with anhydrous ethanol or something, the current situation is unacceptable.

I got 8 grams of crude off white shit at the moment. I am wondering if i can get very pure stuff if I take a new long copper tube, wash all the oxides out with aq HCl so its mad clean, use aluminum foil end plugs (which work well). I just have the condenser problem now, I wish I had a 600mm liebig.

Protip: get ready to stand there with a long wire and unclog that shit every couple of minutes. I also had to flush out the AlCl3 by pumping argon at around 4-5 psi through the thing, otherwise it would just chill in the pipe.


This is defiantly doable on a better scale, I just need to work out the kinks in the operation. For all my work so far I got 8grams, but I noticed I had quite severe losses due to inefficient cooling. Next run tommorow or middle of the night tonight im gonna daisy chain the liebig and the frederichs condenser, then when its done just pour some anhydrous solvent into it after setting it into a flask and dissolve it out of the condensers instead of scraping, though, this poses the problem of clogs. Maybe I can put a clansien conector between the frederichs and liebig and leave it capped, but uncap it once in a while so I can poke at the clog with a steel wire...

[Edited on 28-7-2010 by Chainhit222]

[Edited on 28-7-2010 by Chainhit222]

chemrox - 27-7-2010 at 19:03

everybody except me already knew that a "barby" is a gas-fired barbecue oven? where have I been? I must however protest the substitution of the plural of an British/American volume unit for the conmon term for pure silica glass. Having got my little barns in, why do this, AlCl3 is cheap. It does need to be pure for most purposes ....

Chainhit222 - 27-7-2010 at 19:17

Quote: Originally posted by chemrox  
everybody except me already knew that a "barby" is a gas-fired barbecue oven? where have I been? I must however protest the substitution of the plural of an British/American volume unit for the conmon term for pure silica glass. Having got my little barns in, why do this, AlCl3 is cheap. It does need to be pure for most purposes ....


I don't know of a source of anhydrous AlCl3 that will sell to a house in the suburbs.

Why can I not just recrystallize AlCl3 in a solvent? Why must it be sublimed?

[Edited on 28-7-2010 by Chainhit222]

spong - 28-7-2010 at 03:08

Wow that's a really good setup, even if the yields aren't the best who cares, it costs a few dollars to set up.
I'm definitely giving that a shot once we get a new gas cylinder for the BBQ :D

peach - 28-7-2010 at 04:49

Quote: Originally posted by Chainhit222  
i was running around my yard with a leaf blower in a gas mask shooing clouds of alcl3 away so my neighbors would not get suspicious if the cloud traveled into their yard :x
I hope they did not see me
[Edited on 28-7-2010 by Chainhit222]


If you see my DCM method for this, that's pretty much what I ended up doing with the results when the neoprene was in contact with the acid and solvent. The smoking was stupid. I was standing in my undercrackers on the lawn trying to wash huge plumes of persistent white smoke out of the air before the fire brigade arrived, for about two or three hours.

I don't know what grade the aluminium is, other than that it's aluminised. They make it by spraying molten aluminium through a nozzle to make a fog which is then cooled and solidified as it is in a spray dryer. They break the particles up by playing ultrasonic vibrations through it as it leaves the nozzle to form micronic aluminium droplets; like a cold humidifier.

The aluminium you might be thinking of is German blackhead / Indian black. Spheres distribute heat / pressure etc over their surface better than any other shape. So spherical, atomic aluminium doesn't ignite so well at low temperatures. The pyrotechnic grades are made by putting it through rollers between pieces of paper, to squash it flat. That flattens it to square like shapes with sharp edges, where heat will concentrate to raise the temperature and cause ignition. The paper is burnt off afterwards, leaving a carbon coating. Hence it's name 'black'.

It took me a good amount of google searching to find out that precise reasoning.

I would suggest, if you have a glass wash head, you try my solvent method again. I'll be trying it again.

It's the neoprene that caused the problem, it was working fine before that, and I'll try it again once I have my glass back.

The reason I'm trying it over the hot method is, like you say, it'll solidify and clump up in the glass. Since it doesn't melt and only sublimes at 100C+, you can't simply pump warm water through the condenser.

The only thing I can suggest is hooking it up to the fridge pump. You could stick the receiver bend into the flask and extend it with some tubing, then fill the flask with some broken glass and put the flask in some ice water. The AlCl3 may make it through to the flask, where it'll solidify and wait for you to dissolve it afterwards.

But, as I say, this is why the glass DCM method would be so nice, because it'd be extremely pure and precipitates as a fine deposit, see; those pictures of the amber bottle. That is AlCl3, whatever BlogGimp wishes to think.

Quote: Originally posted by chemrox  
everybody except me already knew that a "barby" is a gas-fired barbecue oven? where have I been? I must however protest the substitution of the plural of an British/American volume unit for the conmon term for pure silica glass. Having got my little barns in, why do this, AlCl3 is cheap. It does need to be pure for most purposes ....


Jumpin' jelly beans! You didn't realize a barby was a BBQ. Shit.... :P

As chainhit says, the anhydrous salt is not at all easily available without accounts.

I agree that FeCl3 etc contaminated Lewis acid will function for a lot of things. But, when it's being used for experimentals where I don't know what colours or changes to look for, they do not help at all. E.g. My commcercial grade acid stained my solvents of choice so dark brown I couldn't see through them with it held up to a light. That instantly increases the chances of incorrectly identifying something as intractable tar.

As I've said on other forums, I can order a huge number of things from genuine suppliers. I wouldn't mind if they spontaneously phoned me or asked to visit if they were bothered about an order, but I hate the idea of them closing the road off, getting their suits out and smashing the door down at 3am because I'm a member of the public and they think I'm churning out drugs or bombs.

It's also part of the fun, seeing what I can make at home better than the lab suppliers. It's not all that hard to surpass what gets passed off at CP grade, and it can be done for not a lot of effort and similar or lower price.

The AlCl3 depositing in my amber bottle was pure white. The CP grade was yellow, after weeks of rinsing the near opaque brown shit off it. I'd make it at home even if it was more expensive than the CP grade to be sure of what I had.

If we just ordered what we liked form suppliers, this forum wouldn't exist.

[Edited on 28-7-2010 by peach]

bbartlog - 28-7-2010 at 04:57

I'm curious about the temperature seemingly required for this reaction. AlCl3 sublimes around 180C. Why push the tube to 450C? Does it actually need to be that hot for the reaction to proceed to completion, or are you just making it that hot so that the vapor reaches your condenser without condensing prematurely? 200C would be more easily managed in some respects - for example, you could use PTFE in places where a hotter setup would destroy it, and it seems like vapors would be less likely to escape your condenser.

peach - 28-7-2010 at 05:15

I don't know what the precise temperature is for the hot, solvent free HCl(g) + Al method, but just that the result sublimes at 180C does not mean the compound will form at 180C; e.g. NaOH takes hundreds of degrees to melt, with the extracted sodium melting more than three times below that.

I'd prefer to see more people trying the cold method personally. If it reaches a similar efficiency, why cook the equipment and have to put up with clogs over fine precipitates.

Chainhit222 - 28-7-2010 at 05:35

When I had the flame guard on the bbq (it would only reach 300c or so) there was no reaction between HCl and Al foil. It seems as if the temperature has to be around 400c before it begins to react

Chainhit222 - 29-7-2010 at 15:23

I managed to make a bit more today:
http://img202.imageshack.us/img202/9938/hitthatshit.jpg

This stuff is much cleaner (copper pipe + hcl w/drying tube and aluminum foil plugs). It seems to have a slight discoloration still, not perfect white. Vacuum sublimation is my only hope D:

peach - 30-7-2010 at 04:25

You've got way too much angry bird contamination thar pirate!

If it's tinted limey green, that'll be moisture or iron contamination (more so the iron if it has a yellowy tint). The iron could be from traces in the pipe or the aluminium source.

If it's moisture, you didn't mention what the drying tube was full of, using 98% sulphuric may help with that.

If it's brown, that may be iron again, but I don't know why it'd be brown. Leaving it to soak in just enough DCM to cover it for hours or days will help remove that; rapid rinsing with excess doesn't seem to work anywhere near as well. It's not particularly soluble in DCM either.

Take care with your tapers, as I've had glass to glass seize when DCM + AlCl3 has come into contact with them for prolonged periods. To the point that it needed smashing open; no solvent, heating, tapping or reagent treatment would get it open again (I spent three weeks gently teasing it to no avail).

When you store it, use a screw top bottle and wrap the threads with PTFE tape. If they're not wrapped, it can escape; my sealed commercial bottle rotted it's own label without me even breaking the seal, so taping the threads is a good idea.

I'm just doing some AlI3 demethylation work now and making a gigantic video blog of the process. Seems to be behaving finally. You get a mention in the video and I'll probably give this a go with some copper myself, or a rogue pipette you'll see in the video. I'm going to try with a DeWalt hot air gun and one of those pipe sweating nozzles. I don't have a thermometer that'll read to 400C, but I do have one to 300C. So I'll be able to investigate how linear the temperature rise is on the infinitely adjustable dial and then work out roughly where the temperatures are above that based on the dial position. That may allow me to find a more exact temperature.

400C is getting close to the maximum recommended for borosilicate, so copper pipe may actually be a good choice if you're not going for quartz. Particularly if it's going on the barby, might go over that temperature and the glass is ground.

[Edited on 30-7-2010 by peach]

bbartlog - 30-7-2010 at 06:27

Anhydrous CuCl2 is brown. Damp FeCl3 likewise. FeCl2 hydrate *would* be green but I would not expect it to be able to grab the water before the AlCl3 did.

Chainhit222 - 30-7-2010 at 12:54

I seem to have alot of hydrate in my product. I vacuum sublimed some, and the left behind stuff is not particularly reactive with water. I might just have to do the iodine method :(

It must be reacting with the atmosphere during production. I wonder if pumping a mixture of argon and hcl would help. There is also some FeCl3 in my product (nice yellow color), I assume this means the pipe is impure.

Any idea what else is in aluminum foil or copper pipe? What kind of contaminants am I dealing with?

[Edited on 30-7-2010 by Chainhit222]

12AX7 - 30-7-2010 at 15:19

Copper pipe is about 99.9% or better, it's very pure stuff.

Aluminum foil is not particularly pure, perhaps 97%. The main impurities are Si and Fe.

Tim

Chainhit222 - 30-7-2010 at 16:39

Would a slight contamination of iron chloride (from the foil) effect the gatterman reaction? Specifically 1,4-dimethoxybenzene to 2,5 dimethoxybenzaldehyde (benzene with alcl3 + hcn/hcl)

[Edited on 31-7-2010 by Chainhit222]

spong - 13-8-2010 at 04:50

In Organic Reactions v5 (from the library section) it says "An industrial grade of aluminum chloride may be employed as catalyst. Its chief impurity is ferric chloride.....There are no statements in the literature which report any advantage in using highly purified aluminum chloride."
Although that is talking about the method that uses CO not HCN but is there really that much of a difference between the two? Is there any advantage to HCN? I'd be much more comfortable using CO.
What size copper pipe did you use? 3/4" or 1"?

entropy51 - 13-8-2010 at 05:59

Some arenes can be formylated with a Gatterman using zinc cyanide and gassing with HCl, thus avoiding the need to gas with either CO or HCN. There will of course be some HCN byproduct, but with good ventilation I think it is safer than gassing with HCN + CO. (Isn't everything?)

Chainhit222 - 13-8-2010 at 13:53

I am trying the 1,4-dmb with glyoxylic acid route for now, but I want to do gatterman too and compare them. Aparrantly it works much better with 2-bromo-1,4-dmb, but I don't really want the bromine atom there :(

My pipe is 1 inch ID.
I suggest you use something thicker then a 24/40 liebig condenser to condense the AlCl3, it clogs up WAY too easily. I was thinking a 300mm glass 24/40 tube, then put a liebig on the end of that, hopefully it would be a more even distribution and not clog so much. Then you could simply use a pipe cleaning brush to get your AlCl3 out. When a clog forms its pretty hard to unclog...

[Edited on 13-8-2010 by Chainhit222]

spong - 13-8-2010 at 16:29

Ohh I see, well that would probably be better than using such a large amount of AlCl3 on the Gattermann reaction.
Would a small plug of cork attached to a rod make poking it out of the condenser easier? I was planning on running it and periodically disconnecting the condenser and ramming that down and collecting the powder in a container then putting it back.
If it clogs too easily I might try having a female-female joiner at the end of the reaction tube and then more copper pipe attached (perhaps I could cool it with the hose too) so it could be run for much longer, then the second half can be disconnected and scraped out in a similar way. It'd also be easier to cram more foil back in the tube while it's still hot hopefully.

entropy51 - 13-8-2010 at 16:42

If you keep the entire tube hot, you can sublime the AlCl3 out into a receiver at room temperature instead of letting it clog the reaction tube. But you need something like a glass rod running through a plug of asbestos tape to clear out blockages that do form, no matter what you do.

It might be worth mentioning that some Friedel-Crafts can be run using Al, sometimes Al(Hg) instead of AlCl3.


major_tom3 - 29-8-2010 at 17:17

Guys, please excuse a beginner's naive questions.

Background: I need an anhydrous Lewis acid, say AlCl3 or FeCl3.
1. I want to do a reaction in CH2Cl2 so what I was going to do was:
- buy FeCl3 crystals, readily available for etching printed circuit boards.
- dissolve in dic
- stick in loads of drying agent, say sodium sulphate
- agitate, wait until I get bored
- filter and use
Now I'm guessing this won't work, or you lot wouldn't be playing with chlorine in your back yards.
Can someone point out the flaw in my master plan?

2. Is FeCl3 far inferior to AlCl3?

Thanks in advance.

mr.crow - 29-8-2010 at 17:45

Ground control to major tom:

Think of the water as an integral part of the molecular structure. When hydrated Al3+ becomes more like [Al(H2O)6]3+

Drying can be done with thionyl chloride which reacts with the water replacing it with Cl

peach - 29-8-2010 at 20:58

Given the level 4 rating it scores on the NFPA 704 fire diamond, coupled with it being controlled under the chemical weapons acts, I would recommend you don't use thionyl chloride.

You can dry FeCl3 hexahydrate (the dark yellow) with heat under a stream of hydrogen chloride gas.

A number of lewis acids behave this way with regards to drying by heat, they start fuming off hydrogen chloride gas as you try to dry them. By running them under that gas, they don't.

Lewis acids are roughly grouped into hard and soft. The hard and soft groups alone aren't perfect definitions, there are difference between the acids within those groups in terms of how aggressively they seek out electron pairs.

To produce clean, anhydrous lewis acid by thermally drying the damp veriations, you'll need to produce a clean, dry stream of hydrogen chloride gas. If you've not done this before, I would suggest practicing first, bubbling it into water to make up some hydrochloric acid. And starting with small amounts.

The gas isn't systemically toxic, but it's beyond 'a bit reactive' or 'a bit smelly'. It'll rot stainless and chrome fittings, normal keck clips fall to bits when exposed to very tiny leaks through the tapers, tubing goes 'funny', tubes tend to block up as things react at their ends and so on.

Drip some concentrated sulphuric acid on some table salt in a tiny test tube, then have a deep sniff and see if it's something you want to make a lot of. Be prepared for a 30 second long, involuntary coughing seizure. :P

[Edited on 30-8-2010 by peach]

redox - 5-4-2011 at 02:58

Well put, Peach. :D Your description of HCl is spot-on.

White Yeti - 31-7-2011 at 12:22

I'd like to carry out a Friedel–Crafts very soon, so I'd like to give this a shot. I don't have a gas grill, instead I have a charcoal grill that can definitely get up to temperature, I've melted aluminium in it once upon a time, and steel can glow red hot if I force air into it, so temperature is not a problem. I also have some sodium bisulphate that I can mix with salt to generate HCl.

However, I'm wondering if I can use a glass condenser for re-condensing aluminium chloride vapours. Won't soda lime glass crack under the temperature gradient? I mean, one side is at 400C+ and the rest is at 20C. Could I use a copper tube instead?

Thor - 31-7-2011 at 12:47

Quote: Originally posted by White Yeti  
I'd like to carry out a Friedel–Crafts very soon, so I'd like to give this a shot. I don't have a gas grill, instead I have a charcoal grill that can definitely get up to temperature, I've melted aluminium in it once upon a time, and steel can glow red hot if I force air into it, so temperature is not a problem. I also have some sodium bisulphate that I can mix with salt to generate HCl.

However, I'm wondering if I can use a glass condenser for re-condensing aluminium chloride vapours. Won't soda lime glass crack under the temperature gradient? I mean, one side is at 400C+ and the rest is at 20C. Could I use a copper tube instead?


I am also planning on trying this soon. The Bisulphate sounds like a nice way to generate dry HCl, although according to wiki, the reaction proceeds at 200C. I suppose you could do it all in the BBQ :D.

I planned on having the copper tube exiting straight into an old jar surrounded by ice water. Dunno if this will be sufficient though.

White Yeti - 1-8-2011 at 05:16

"I am also planning on trying this soon. The Bisulphate sounds like a nice way to generate dry HCl, although according to wiki, the reaction proceeds at 200C. I suppose you could do it all in the BBQ :D.

I planned on having the copper tube exiting straight into an old jar surrounded by ice water. Dunno if this will be sufficient though."

Sounds like a nice idea, however the jar with the ice water sounds like a failed venture from the start. There's a reason why the OP used room temperature water. If you use ice water any water that was present in the tube would re-condense and contaminate your anhydrous aluminium chloride.

bbartlog - 1-8-2011 at 05:34

Quote:
There's a reason why the OP used room temperature water. If you use ice water any water that was present in the tube would re-condense


Your reasoning is incorrect. If there is water in the tube, it will already have combined with the AlCl3 (which will then not be anhydrous). The use of rt water is likely just a matter of convenience; if you're condensing something with a bp of 158C then the difference between 0C water and 20C water is not worth worrying about.

Thor - 1-8-2011 at 06:34

Quote: Originally posted by White Yeti  

Sounds like a nice idea, however the jar with the ice water sounds like a failed venture from the start. There's a reason why the OP used room temperature water. If you use ice water any water that was present in the tube would re-condense and contaminate your anhydrous aluminium chloride.


At these reaction temperatures, any water in the system will be long gone before the reaction begins. If you where using wet HCl then of course water would be continually added. But your Bisulphate method does not start producing HCl till 200C. Water will not be a problem.

White Yeti - 1-8-2011 at 08:01

To bbartlog & Thor.

I understand. But how were you planning on attaching the jar to the copper tube and putting a vent without letting atmospheric humidity contaminate the condensed aluminium chloride?
My reasoning is that you need to have some kind of tube between the copper tube and whatever condenser you plan to use (since the temperature gradient would crack any kind of glass, including boro). Also, you can't attach the jar hermetically because you need some kind of vent for the hydrogen gas that is evolved. The problem: once the HCl generator stops producing hydrogen chloride, the gases inside the copper tube are still very hot. When the temperature goes down, the gasses contract, reducing the pressure and causing humid air to get sucked in through the hydrogen vent. Since the jar the air would be entering into would be at 0C, it's only logical to think that atmospheric water would condense on its sides and contaminate the product. If air doesn't get sucked in, the tube or the jar would implode, making a mess, and wasting your time.

How would you deal with this problem? The OP has an argon tank, but what would normal people use?

White Yeti - 1-8-2011 at 08:05

If 20degC water was used, very little atmospheric water would condense onto the sides of the jar when air gets sucked in.

Thor - 1-8-2011 at 09:06

A good point. I was thinking of brazing the tube into the top of a jar, with a metal lid, or even using a compression fitting. A few could be run in series to stop moisture entering and to maximize capture of the AlCl3. I have a cylinder of argon, but I feel it may be overkill. I also have lots of glass, but some things are more suited to some metal thrown together.

White Yeti - 1-8-2011 at 09:22

I was just thinking about using a long, straight copper tube condenser cooled with room temperature water. That way, the AlCl3 condenses, atmospheric humidity does not, the H2 flows out the other end of the copper tube and no glass in involved. To remove the product, I will take another tube, slightly thinner than the condenser, and push the crystals out into a vial with desiccant for storage.

bbartlog - 1-8-2011 at 12:59

Quote: Originally posted by White Yeti  
To bbartlog & Thor.

I understand. But how were you planning on attaching the jar to the copper tube and putting a vent without letting atmospheric humidity contaminate the condensed aluminium chloride?
My reasoning is that you need to have some kind of tube between the copper tube and whatever condenser you plan to use (since the temperature gradient would crack any kind of glass, including boro). Also, you can't attach the jar hermetically because you need some kind of vent for the hydrogen gas that is evolved. The problem: once the HCl generator stops producing hydrogen chloride, the gases inside the copper tube are still very hot. When the temperature goes down, the gasses contract, reducing the pressure and causing humid air to get sucked in through the hydrogen vent. Since the jar the air would be entering into would be at 0C, it's only logical to think that atmospheric water would condense on its sides and contaminate the product. If air doesn't get sucked in, the tube or the jar would implode, making a mess, and wasting your time.

How would you deal with this problem? The OP has an argon tank, but what would normal people use?


Ah, now I understand your reasoning and it makes sense. However, a drying tube or something similar (at the end, where atmospheric air is going to get sucked back in) would be more reliable than trying to condense the moisture; in particular 0C is hardly going to get all the moisture out of the air. Having an exhaust tube stuffed with baked-dry cotton balls is one way.

As for the connection between copper and glass, yes... some sort of luting is needed.

MeSynth - 26-8-2011 at 12:35

Ok so what about storage? Can it be stored in a hot garage? My guess is that it can since it is formed at high tempuratures. It will not decompose in a hot garage I am sure.

Waffles SS - 9-7-2013 at 08:37

Is this possible to dehydrate Aluminium Hexahydrate by Thionyl Chloride(SOCl2)?


Quote:

ANHYDROUS METAL CHLORIDES

MCln.xH2O + xSOCl2 + MCln + xSO2 + 2xHCl

General methods for the preparation of anhydrous chlorides have been
described by Tyree. Of the methods listed for dehydrating metal chlorides,
that involving treatment with thionyl chloride has the advantages of
convenience and simplicity and requires no special apparatus. This method is
generally useful regardless of the periodic group in which the metal appears.

Anhydrous Metal Chlorides
Robert J. Angelici
DOI: 10.1002/9780470132593.ch80




[Edited on 9-7-2013 by Waffles SS]

Metacelsus - 9-7-2013 at 16:17

Yes, but from the perspective of the amateur chemist, why? It's much easier to make anhydrous AlCl3 than it is to make SOCl2.

Quote: Originally posted by peach  
Given the level 4 rating it scores on the NFPA 704 fire diamond, coupled with it being controlled under the chemical weapons acts, I would recommend you don't use thionyl chloride.
[Edited on 30-8-2010 by peach]

testimento - 9-7-2013 at 18:45

Thought to give a hit for this one.

How about this kind of reactor:

Steel body, with ceramic clay inner and nicr heater wire
Quartz or boro tube blowing dry chlorine gas
Melt aluminium at 650-700C
Blow chlorine into it
AlCl3 will form and distill up to tube
The tube is heated too
Tube goes into cooled receiver where alcl3(FIXDED) should accumulate

Any ideas how to effectively prevent clogging the tube? Planning of using at least 3/4" or 1" steel tube.



[Edited on 10-7-2013 by testimento]

acl3.png - 22kB

[Edited on 10-7-2013 by testimento]

bfesser - 9-7-2013 at 18:50

You're using "nicr" wire, -50 × C, exhaling chlorine, forming "AlCl3," and collecting "al2o3"‽

[Edited on 7/10/13 by bfesser]

watson.fawkes - 9-7-2013 at 20:04

Quote: Originally posted by testimento  
How about this kind of reactor
How about a starter project? A propane-powered lime furnace is fairly easy, and you'll learn about the difference between oxidation and reduction firing. Maybe an electric furnace that can fire red earthenware at cone 2. You'll learn a lot, at least enough to know that your grand plans are currently beyond you.

testimento - 9-7-2013 at 20:28

Actually, I already obtained the material for both of them, but Im still waiting for the nichrome wire and glass tube. I'll be pleased to post pics of the process soon when the stuff comes. I've got several other things to do at the moment, including the furnace, so not today. :)

Waffles SS - 10-7-2013 at 22:54

Quote: Originally posted by Cheddite Cheese  
Yes, but from the perspective of the amateur chemist, why? It's much easier to make anhydrous AlCl3 than it is to make SOCl2.

Quote: Originally posted by peach  
Given the level 4 rating it scores on the NFPA 704 fire diamond, coupled with it being controlled under the chemical weapons acts, I would recommend you don't use thionyl chloride.
[Edited on 30-8-2010 by peach]


I have access to thionyl Chloride,but it seems it just can dehydrate Aluminium Chloride Hexahydrate not Aluminium chlorohydrate(PAC).
Adding aluminium metal directly to thionyl chloride is possible route to anhydrous AlCl3?

Waffles SS - 2-9-2013 at 02:22

I tried to dehydrate Aluminium Chloride Hexahydrate by Thionyl chloride by below instruction.

Quote:

General methods for the preparation of anhydrous chlorides have beendescribed by Tyree.' Of the methods listed for dehydrating metal chlorides,that involving treatment with thionyl chloride2 has the advantages ofconvenience and simplicity and requires no special apparatus. This method isgenerally useful regardless of the periodic group in which the metal appears.
Anhydrous Metal Chlorides
Robert J. AngeliciAlfred R. Pray1,Richard F. Heitmiller2,Stanley Strycker2,Victor D. Aftandilian2,T. Muniyappan2,D. Choudhury2,Milton Tamres2
Published Online: 5 JAN 2007
DOI: 10.1002/9780470132593.ch80



I used 120gr(AlCl3.6H2O) and 350gr(SOCl2).I have to say nothing happened after adding resulting powder to water.No heat No vapor no gas.
I dont think SOCl2 is effective substance for dehydrating Aluminium Chloride Hexahydrate




DSC00063.JPG - 42kB

Waffles SS - 10-9-2013 at 10:28

Dehydration AlCl3.6H2O by Thionyl Chloride

2013-08-04 10.05.35.jpg - 40kB 2013-08-04 10.02.55.jpg - 42kB2013-08-04 10.01.31.jpg - 39kB 2013-08-04 09.59.20.jpg - 40kB
2013-08-04 10.08.23.jpg - 55kB 2013-08-04 09.58.46.jpg - 51kB




[Edited on 10-9-2013 by Waffles SS]

ChemistryGhost - 11-6-2014 at 14:21

Quote: Originally posted by Chainhit222  
I just made anhydrous aluminum chloride. You will need:

-aluminum foil
-a barby
-chlorine or hcl gas source
-a piece of metal pipe (i used copper)
-some way to connect it all together (i afro rigged it)

my setup was:
1) flask connected to a addition funnel (ground glass 24/40)
2) a hose (i used tygon, vinyl is fine) leading from the hose barb on the flask to a ground glass vacuum take off thing wrapped in electrical tape and wedged into a copper tube filled with aluminum foil from the food store laid across the barby
3) a liebig condenser cooled with room temp water with one end wrapped in electrical tape wedged into the end of the pipe

I preheated the barby as high as it would go (seems to be like 450c) (take off the flame guard if it has one) and then laid the pipe on it. At this point the pipe was being flooded with argon gas so the aluminum would not oxidize (i dont think it was necessary, but why not if you got a tank). After I was confident that the pipe and reactants were hot enough I switched the hose from argon to the hcl gas generator and turned it on.

AlCl3 began to sublime and condense in the liebig. Once I ran out of hcl gas I took the liebig off and put it over a container. I then took a clean plastic glassware brush and pushed/twisted it through the liebig, which caused the alcl3 to fall out into my container. Id recommend a large chlorine gas generator, I ran out of chlorine so I just got a few grams of AlCl3 which is very slightly contaminated with burnt electrical tape.

If you actually wanna do this, I would recommend adding a drying tube for the chlorine or HCl gas, and using some kind of heat resistant material (maybe muffler tape?) to make a connection between your glassware and the copper pipe.

http://img807.imageshack.us/img807/241/thugfurnace.jpg (picture of setup)
http://www.youtube.com/watch?v=bpi7cX5d0iw (youtube video of reaction)

Why not use a quarts tube you ask? Because I cannot afford a quarts tube or a tube furnace. I have 12$ in my wallet.

[Edited on 26-7-2010 by Chainhit222]

[Edited on 26-7-2010 by Chainhit222]



Could gallium be used to amalgamate aluminum and make it more reactive towards chlorine or HCl gas? Gallium makes aluminum react as if it has no oxide. If gallium is useful in this case, it would possibly make the reaction go quicker and only be a matter of avoiding the use of aluminum tubing and using proper equipment. :P

Brain&Force - 11-6-2014 at 14:25

Aluminum reacts with HCl on contact, so gallium is not necessary. You just need to keep water out of the mix if you want anhydrous AlCl3.

bbartlog - 1-10-2014 at 19:22

Quote: Originally posted by Brain&Force  
Aluminum reacts with HCl on contact


Aluminum does not react with dry HCl at room temperature.


[Edited on 2-10-2014 by bbartlog]

bbartlog - 1-10-2014 at 19:56

Some short notes on an unsuccessful attempt to prepare anhydrous AlCl3, which might save someone the trouble of trying the same thing in future:

There are some papers that describe the use of methyl sulfonyl methane (dimethyl sulfone) as a solvent for AlCl3, from which solution aluminum can be plated out. For example: http://www.sciencedirect.com/science/article/pii/S0257897212... . Apparently, AlCl3 is at least somewhat stable in this solvent.

Reading this it occurred to me that it might be possible to dissolve anhydrous CuCl2 in MSM, and then use this solution to dissolve or react with elemental aluminum, presumably reducing the copper and oxidizing the aluminum to AlCl3, with the solvent also acting as thermal buffer (this reaction is very exothermic). Although I couldn't find solubility figures for cupric chloride in MSM, it's at least somewhat soluble in a wide variety of solvents.

Accordingly, I dried some CuCl2 in an oven (grinding in a mortar and redrying once). 6.72g of CuCl2 and 150g of MSM were placed in a 1L flat-bottomed round flask that had likewise been dried in an oven. With heating on a hotplate, the MSM melted and some (but not all) of the cupric chloride dissolved. I then added the aluminum, which was in the form of five small millimeter-thick pieces cut from some flashing. This appeared to be mildly exothermic, as the solution bubbled around and above the aluminum bits.

White crystals sublimed and condensed on to the upper portion of the flask ... anyway, long story short, when I re-melted this the next day, half the aluminum was unreacted and covered with a black film; the solution had a lot of dark particulate in it, which did not dissolve in dilute (~1%) HCl; there was a somewhat acrid smell on opening the flask, but not the fuming or HCl stench that I would expect if significant quantities of AlCl3 were present. Looks rather as if sulfides form (from reduction of the MSM, I suppose) and cripple the reaction.

Anyway, while it might be possible to tweak this somehow (maybe keep it just above the melting point of MSM, or use a co-solvent to make it liquid at even lower temps), it doesn't look too promising after the first attempt.

byko3y - 31-5-2015 at 11:15

I'm so funking pissed after reading about how it is easy to perform anhydrous AlCl3, while they have no idea about the reaction, and I'm so tired after spending few days building actual devices and trying different modes, yet my only success was something like 20-30 g of AlCl3 and a lot of HCl smoke all over the room, because I have no idea how to perform the reaction without massive HCl leakage and AlCl3 hydrolysis having no special equipment.
I want to pinpoint some problems/mistakes:
- you can't do a straightforward Al+HCl or Al+Cl2 - they won't react at all (anhydrous!);
- and even heating to 100°C is not enough, reaction starts somewhere at 200°C, but optimally is run at 300-800°C;
- the reaction is exothermic, that's why you can actually see the aluminium burning (glowing red) in the HCl/Cl2 flow, if it flows fast enough, this can make your reactor crack;
- this crap obliterated everything that is colder than 180°C, inlets, outlets, walls, and you condenser is usually a big vessel with flat walls, which is a bad condenser in fact, that's why the AlCl3 easily makes its way to HCl outlet, clogging it and making you breath a life-given hydrogen chloride;
- producing 50 g of AlCl3 via HCl method can make a nice hydrogen explosion, destroying the room, until you properly dispose it (fume hood, draw it outside, burn, catalytically oxidize);
- I see no way to make appreciable amount of AlCl3 without complex heating of reactor part of the system, because you need to keep the very end of the reactor outlet hot, while condenser right next to it should be cold;
- simax/duran/etc bottle as a condenser is capable of processing not more than 20 g of AlCl3 without disassembing the apparatus (it has polypropylene blue or polybutyleneterephthalate red ring which are relatively heat-labile);
- you need to pass the HCl/Cl2 through a lot of aluminium, otherwise most of the gas will pass unreacted, because aluminium does not readily reacts with those gases.
Here's brauer's device that worked for me, until had been clogged.
Brauer AlCl3.png - 35kB

Aluminium amalgam is a known catalyst of Friedel-Crafts, most likely reacting with chlorine in-situ. Maybe some other alloy will work (copper?) or even a bare aluminium:
"AlCl3 prepd. according to Radzivanovskii [Ber. 28, 1135(1895)] from Al and HCl is an active Friedel-Crafts catalyst.
C6H6 (200 g.) and 4 g. Al shavings treated with dry HCl until a brown coating covered the catalyst, then with 100 g. EtBr, and let stand 48 hrs. at 10-12°, followed by refluxing 2 hrs., gave 73% EtPh, b. 132-4°, d*° 0.8703, nD20 1.4950, 16-18% Et2C6H4" - The activity of aluminum chloride prepared by the method of Radzivanovskii (benzene alkylation) 000505318-Chem_Abs_45_Friedel_Crafts_with_Al_catalyst.pdf
Also see this thread http://www.sciencemadness.org/talk/viewthread.php?tid=5799
And those guys http://pubs.acs.org/doi/abs/10.1021/ed066p176 claim they've managed to perform Friedel-Crafts with a bare aluminium metal (reaction of secondary alkyl halide with toluene, aluminium wire activated by polishing it right before addition to the reaction mixture).
Tell me I can't use TFSE and the problems I state are already solved, thus every amatuer chemists can easily make AlCl3 on 1 mole scale.

blogfast25 - 31-5-2015 at 11:49

My simple preparation of AlCl3: Reduction of anh. ZnCl2 with Al powder:

http://www.sciencemadness.org/talk/viewthread.php?tid=30150&...

byko3y - 31-5-2015 at 20:17

Thanks, you have posted it the second time to me. I mentioned it in my last message. This was a setup I used the first time (brauer's apparatus), and it partially worked.

SimpleChemist-238 - 1-6-2015 at 03:22

Why not use a long thick glass tube as a reaction vessel and place Aluminium powder into it?

byko3y - 1-6-2015 at 04:46

You can't use a thick one - you need to use thin, because of a possible strong overheating (from 200°C to 700-800°C). I was using a tube 1.8 mm thick, worked okay. Porcelain 5.5 mm thick has thermal shock resistance of 230-280°C http://www.hindawi.com/journals/je/2013/972019/ , while this number is as low as 230°C for my pyrex glass tube (1.8 mm).
I don't think there's much difference in the kind of aluminium I use, turnings work fine, even aluminium wires will work.
I've already explained the problem: it is about exothermic reaction, clogging and long contact time. Contact time is okay in a long glass tube, but clogging will be a problem, you need to heat the tube all the way to the reciever.

byko3y - 2-6-2015 at 01:47

After some research I came to understanding: if you are an amateur chemist - you don't need the AlCl3. The only reason it is used industrially is to produce a large amount of something either spending:
- 4000$ for AlCl3;
- 20,000$ for AlBr3;
- 200,000$ for AlI3.
But it is hard to transport the chlorine because it is a gas, so usually some solid carrier is used. NaOCl readily decomposes over time, isocyanurates and 5,5-dimethylhydantoin cost 10$ per kg, CaCl(OCl) might be a cheap source of chorine, but who cares about those few buckses? For most cases the minimum is 5$ per 1 kg of Cl2, while cost of bromide salt is 10$/kg.
Using TCCA as a chlorine source, for an amateur chemist the difference is 12$ for 14 moles of AlCl3 and 25$ for 14 moles of AlBr3. Do you really want to mess with chlorine, to heat the aluminium up to 200-300°C in a continious flow apparatus, while you can just slowly pour a liquid bromine into aluminium turnings and enjoy a nice sparky and colorfull reaction? Or maybe you want to generate a hell lot of hydrogen trying to perform the AlCl3 synthesis via HCl?
Human can detect as low as 1 ppm of chlorine or bromine in the air, 10 ppm is unbearable, chlorine has IDHL of 10 ppm and 3 ppm for bromine (it's not LC50, rather highest safe value for prolonged exposure). http://www.cdc.gov/niosh/idlh/7726956.html
I have never had any health problems with chlorine, and once I even had briefly breathed it in - that really hurt my nose and I had a burning sensation in it for half of a day. So I'd say that bromine handling is completely safe unless you are a douchebag huffing the bromine directly off the reaction vessel or sitting in a room full of bromine vapor for a few hours.
I'd like to emphasize, that for many purposes AlCl3, AlBr3 and AlI3 are completely interchangeable, you need the same amount of any of these and you will get the same yields, while some reactions require at least AlBr3 (AlCl3 gives zero yield), and just few can be run on AlI3 only.
For some reason I failed to find similar explanation, and I was sure the AlCl3 is the only thing everybody needs, because almost every book, every article talks about AlCl3. And AlBr3 is just as well soluble in all the solvent where AlCl3 is soluble, so you just substitute one with another and do essensially the same reaction.
PS: and AlBr3 actually melts as low as 97.8°C, making it possible to use a regular distillation setup, not the special sublimation device with complex heating to avoid condensation in a wrong place.
Also, you can make aluminium chloride from aluminium bromide by reaction AlBr3 + CCl4 -> AlCl3 + CBr4.

[Edited on 2-6-2015 by byko3y]

Anhydrous AlCl3 from ZnCl2

ChemPlayer - 19-6-2015 at 10:11

byko3y, I certainly feel your pain (or rather, I did) because a lot of these preparations only seem to work give reasonable yield / purity if you've got the right sizes of flask, gaps, cooling mechanism, set them up just right etc.

I recently spent quite a lot of time tweaking and have figured out a way of using what equipment i have and can boast a 40% yield of AlCl3 using the Zinc Chloride and aluminium powder reaction. And it's decent quality - works a treat for F-C acylations and some demethylations too. I reckon 60% is possible too with some more time.

Video on the process and explanation is here: https://www.youtube.com/watch?v=g7sS69fQMsk

Magpie - 19-6-2015 at 14:03

Very nice work! It will be interesting to see if you (or anyone else) can increase yield.

It seems that deposition plates, or a tube, could be used to capture more of the smoke. But how to get this deposit into a bottle without exposure to humidity would be the trick.
--------------------------------------------------------------------------

Maybe it could be bubbled into an anhydrous solvent like chloroform. Thr chloroform could then be removed by distillation with the vacuum adapter connected to a moisture guard tube.

[Edited on 20-6-2015 by Magpie]

blogfast25 - 20-6-2015 at 05:41

Quote: Originally posted by ChemPlayer  
byko3y, I certainly feel your pain (or rather, I did) because a lot of these preparations only seem to work give reasonable yield / purity if you've got the right sizes of flask, gaps, cooling mechanism, set them up just right etc.

I recently spent quite a lot of time tweaking and have figured out a way of using what equipment i have and can boast a 40% yield of AlCl3 using the Zinc Chloride and aluminium powder reaction. And it's decent quality - works a treat for F-C acylations and some demethylations too. I reckon 60% is possible too with some more time.

Video on the process and explanation is here: https://www.youtube.com/watch?v=g7sS69fQMsk


Hey! Someone put my work to good use and even provided credit! Excellent, well done and thank you! Not to mention a very clear Utoob, for a change...

I never measured yield so that was useful too. I'm convinced yield can be improved very significantly by using a strong excess of Al powder. The low yield is in part due to this being a solid-solid reaction: contact between reagents is by definition quite poor.

My roughly stoichiometric ratio was just a starting point, nothing more. Proof of concept.

Losses at the neck could be reduced by slightly lowering external heat once reaction has been initiated: the reaction is just about self-sustaining (at stoichiometric ratio) and slower evolution of AlCl3 will improve cooling/condensing somewhat. Condensation of the poor heat conductor AlCl3 causes a temperature gradient to form, with the surface of the freshly condensed product being slightly 'hotter' than the glass itself, reducing heat flow slightly. 'Slow is more', here I think.

At the very end, the reaction mixture could then be subjected to some extra heat to convert these last bits of ZnCl2.

Quote: Originally posted by Magpie  

Maybe it could be bubbled into an anhydrous solvent like chloroform. Thr chloroform could then be removed by distillation with the vacuum adapter connected to a moisture guard tube.



Chloroform would have too low a BP for this purpose. The vapours of AlCl3 are at least 100 C, not taking reaction heat into account. Not to mention potential wetting problems.

[Edited on 20-6-2015 by blogfast25]

ChemPlayer_ - 21-6-2015 at 05:40

Thanks for the kind comments :)

You've all got me thinking about various improvements now, and I'm itching to try a couple of variations using slower heating, excess Al powder, and possibly using a quantity of a low bp inert (to AlCl3 and flame anyway) in the receiving container. DCM may be a first choice.

I like the idea that the solvent quickly heating and even boiling off will effectively act as a 'one-shot' rapid efficient heat exchanger for the hot vapours to condense in the receiver, just so long as it doesn't cause a jet coming out of the container expelling all the product with it!

Thursday is my window of opporunity to test so I will let you know...

(Btw had technical issues with original 'ChemPlayer' user so I had to start a new one 'ChemPlayer_').

blogfast25 - 21-6-2015 at 05:55

@ChemPlayer_

I seem to recall lightly grinding the ingredients together, to improve mixing/reduce ZnCl2 lumps (mine's quite lumpy). Increased homogeneity in solid/solid reactions can only improve things.

I also wouldn't be too afraid of a little moisture: water will reduce yield somewhat (due to hydrolysis of AlCl3) but nothing else.

Bear in mind that with an excess Al, the reaction front will already run a little cooler because the excess Al will act as a heat sink. Increasing Al content of the reagent mixture, 'all other things being equal', should increase reaction speed (not really desired, IMO) but mainly increase overall yield.

I'm convinced that with some tweaking, about 90 % yield should be possible.

But I'd be careful with DCM, if I were you. With such a low BP it's recipe for splattering and hence product losses due to mechanical entrainment.

Thanks again!


[Edited on 21-6-2015 by blogfast25]

Magpie - 21-6-2015 at 07:24

I also want to complement you on the quality of your UTube presentation.

As you say the ZnCl2 liquifies before the reaction takes off. So this is really a liquid-solid reaction - a great improvement over a solid-solid reaction.

It seems that at first you are just pushing air out of the adapter and receiving bottle. Then the smoke comes out as most of the air is gone and the production rate overwhelms the receiving bottle. It's fun to watch!

What fraction of the produced AlCl3 do you think is lost due to escape at the adapter-bottle junction?

blogfast25 - 21-6-2015 at 10:30

Quote: Originally posted by Magpie  

As you say the ZnCl2 liquifies before the reaction takes off. So this is really a liquid-solid reaction - a great improvement over a solid-solid reaction.



It's certainly possible but not 100 % certain, IMO. The external heating is weak, reaction enthalpy low and a gaseous reaction product carries away quite a bit of enthalpy. I can't say I saw any liquid ZnCl2, obscured perhaps by the fact there is definitely liquid AlCl3 (you can even see it refluxing in the video). On the other hand, anh. ZnCl2 has a low MP.

Magpie - 21-6-2015 at 10:51

Quote: Originally posted by blogfast25  
The external heating is weak, reaction enthalpy low and a gaseous reaction product carries away quite a bit of enthalpy.


How can you say that the external heating is weak. Didn't ChemPlayer say that the RBF had to be intensely heated for 45 minutes before the reaction takes off?

If the AlCl3 is a liquid when formed it looks like it quickly forms a solid in the form of smoke.

blogfast25 - 21-6-2015 at 12:03

Quote: Originally posted by Magpie  

How can you say that the external heating is weak. Didn't ChemPlayer say that the RBF had to be intensely heated for 45 minutes before the reaction takes off?

If the AlCl3 is a liquid when formed it looks like it quickly forms a solid in the form of smoke.


4 TO 5 minutes! NOT 45 minutes.

Remember, ChemPlayer got the idea from work I published here and on my own site. Well, in my own two experiments it took about the same time of very mild heating before the reaction started. My mixture was in a large test tube and I only heated the top end of the material (nearest the condenser). After reaction started in my case it was more or less self-sustaining (external heating stopped), I did 'poke' it with the Bunsen a couple of times when it seemed to be slowing down too much. It doesn't take much heat at all to get it going.

The smoke is almost certainly a suspension of solid (already condensed) AlCl3 particles in genuine AlCl3 vapour. If not, it would not slowly waft over into the condenser but get stuck in the connecting pipe. That happened when in an initial experiment I was using 8 mm OD pipe (very stupidly): blockage!

HeYBrO - 21-6-2015 at 23:43

Just out of curiosity, has any one tried to make AlCl3 using anhydrous CuCl2? I know that in solution when you add aluminium to copper chloride it quickly reduces the copper ions to form copper metal and leaves a clear solution. Could be worth a shot to use a procedure analogous similar to blogfast's since copper chloride is easy to come by.

blogfast25 - 22-6-2015 at 06:34

HeYBrO:

The reduction of CuCl2 (anh.) with Al works but it's far more vigorous than for ZnCl2. The reason is the much higher (i.e. less negative) Enthalpy of Formation of CuCl2 (- 206 kJ/mol, NIST) compared to ZnCl2 (- 415 kJ/mol, Wolfram alpha). As a result, the Reaction Enthalpy is much higher.

The reaction is much more like a fast burning thermite, making the formed AlCl3 harder to capture. Not impossible with some smart engineering though...

Someone actually did report such an experiment on this forum several years ago. Search for it if you're interested.


[Edited on 22-6-2015 by blogfast25]

ChemPlayer_ - 22-6-2015 at 09:33

Yes correct just 4-5 minutes but of moderately strong heating.

What is interesting though (and I'm not sure if you can see it on the video because I only included the last few seconds before the reaction started) is that the reaction mixture starts off as a solid (ZnCl2 + Al), then seems to turn mostly liquid and bubbles away for a while (possibly some moisture coming off), but at the point that the reaction starts (and you can see it is at quite a distinct point in time that it 'kicks off') the mixture does look as though it has become mostly solid again.

Running a stoichoimetic excess of Al is an excellent idea and one I'll try in the next run...

blogfast25 - 22-6-2015 at 09:42

ChemPlayer_

Don't forget there's some liquid AlCl3 there too: like in my experiment I can see some of it 'refluxing' back into the reactor.

It's all rather hard to see because there's a solid reagent (Al) AND a solid reaction product (Zn).

ChemPlayer_ - 23-6-2015 at 19:03

So I sneaked in the time quickly to do another run, this time using 100g of anhydrous zinc chloride and 25g of aluminium powder (~25% molar excess).

I used a 500ml RB flask for the reaction plus the same 29/34 'V' adapter tube, but using a larger 1 litre Duran bottle (with similar cold-pack and elastic bands for cooling). My objective was to try as hard as possible to minimise losses from the collection bottle to see just how much product does come over.

Observations:

1. The reaction started faster (~2 minutes) than before.
2. The reaction was slower and steadier, with no 'snow' produced and only puffs of smoke emerging from the collecting bottle during the 2-3 minutes while the main reaction was taking place (objective accomplished!).
3. I saw the liquid mentioned refluxing back into the flask (which didn't violently react with anything, hence I assume you must be right and this is AlCl3 or ZnCl3 as opposed to anything aqueous in nature - not that I imagine water can survive long in those conditions anyway).
4. I stopped after about 5 minutes of heating (paranoid about letting atmospheric moisture into the bottle) because there was hardly any more 'smoke' coming over at this point.
5. The contents of the collecting bottle were much more 'powdery' and less solid adhered to the side of the glass.
6. Empty bottle weighed 565g and with product 598g, so I got 33g of product (~33% yield).

I can only conclude that a lot of the product must be retained in the reaction flask (or the reaction didn't go to completion).

Ok so now I've got the basic set-up nailed (I think) my thoughts on next steps are to see if I can grind up the ZnCl2 into a finer powder (at the risk of atmospheric moisture absorption however) and hence a better surface area with the Al (and maybe slightly greater excess of Al to temper the likely faster reaction a bit).

I have to replenish my ZnCl2 stocks first however as this is quite an 'expensive' process unoptimised! I do have a beautiful 100g+ of AlCl3 collected now though and I may do some more FC experimentation in the interim.

byko3y - 24-6-2015 at 00:35

Considering you can obtain at least 60% yield using a regular chlorine-foil method, I doubt the ZnCl2 way is viable.
Pretty much the only major problem is to move the product all the way through the tube to the receiving vessel and stop it right there. I'm sure this was a major issue in your case.
Asbestos/glass wool/PTFE plug will shield the receiving flask from water.

blogfast25 - 24-6-2015 at 07:37

Quote: Originally posted by ChemPlayer_  
So I sneaked in the time quickly to do another run, this time using 100g of anhydrous zinc chloride and 25g of aluminium powder (~25% molar excess).
[snip]
3. I saw the liquid mentioned refluxing back into the flask (which didn't violently react with anything, hence I assume you must be right and this is AlCl3 or ZnCl3 as opposed to anything aqueous in nature - not that I imagine water can survive long in those conditions anyway).
[snip]
I can only conclude that a lot of the product must be retained in the reaction flask (or the reaction didn't go to completion).

Ok so now I've got the basic set-up nailed (I think) my thoughts on next steps are to see if I can grind up the ZnCl2 into a finer powder (at the risk of atmospheric moisture absorption however) and hence a better surface area with the Al (and maybe slightly greater excess of Al to temper the likely faster reaction a bit).

I have to replenish my ZnCl2 stocks first however as this is quite an 'expensive' process unoptimised! I do have a beautiful 100g+ of AlCl3 collected now though and I may do some more FC experimentation in the interim.


25 % molar excess is still not really a lot. Of course increasing it further may increase yield but will also waste Al powder.

ZnCl3?

Try heating stronger when the reaction appears to be tailing off. Try and actually liquefy completely towards the end. I think the reaction is not running to completion, due to poor reagent/reagent contact. Even if you reached the BP of ZnCl2 (756 C), it would condense back in the higher, cooler part of the flask.

Quote: Originally posted by byko3y  
Considering you can obtain at least 60% yield using a regular chlorine-foil method, I doubt the ZnCl2 way is viable.
Pretty much the only major problem is to move the product all the way through the tube to the receiving vessel and stop it right there. I'm sure this was a major issue in your case.


Depends what you call viable: it’s not intended as an industrial process. As a set up it’s a lot easier than having to deal with HCl or Cl2. That’s why I tried it.

You wouldn't be writing that second sentence if you had witnessed it yourself. Losses through the gap are quite modest but could be further reduced, for sure. Condensing AlCl3 w/o losses with the HCl/Cl2 method faces the same problems.

[Edited on 24-6-2015 by blogfast25]

ChemPlayer_ - 24-6-2015 at 17:40

I think you're both right.

Losses from the gap are now really minimal using the larger bottle so it's a challenge of moving the product into the collection vessel, or getting the reaction to run to completion; I suspect both are the issue.

For me this process feels like it holds a lot of potential, having played around with Cl2 gas and Al and nearly gone crazy in the process. If this can product 50-60% then I will be very happy, but I agree that even with 30-40% this is still somewhat useful for the home chemist considering the alternative.

Ultimately though I like the challenge of trying to really understand what's going on here and seeing if this can be optimised. I'm on about reaction 15 now and I don't expect that I've unlocked all the secrets if they are there to be discovered just yet. This is as much for the challenge and understanding as for the end product of having a nice useful anhydrous AlCl3 source.

I will post any more useful findings as and when I get them...

Magpie - 24-6-2015 at 20:47

I wholeheartedly agree that these "solid" reactions are really interesting and present unique challenges for recovery of the product.

The economics are not good as ZnCl2 cost is similar to that for AlCl3. But since AlCl3 is such a powerful and useful reagent who knows if its availability might someday be restricted. I consider the development of OTC procedures for making such reagents to be a high calling for our hobby.

For these "solid" reactions it seems that they really don't take off until some amount of liquid is formed. I'm thinking specifically about the following, of which I do have experience:

1. phosphorus: from (NaPO3)6 (MP = 628°C)
2. benzene: from Na benzoate (MP = 410°)
3. pyridine: from nicotinic acid (MP = 237°C)


[Edited on 25-6-2015 by Magpie]

[Edited on 25-6-2015 by Magpie]

Refinery - 27-6-2020 at 08:49

Age old topic, but I made a quartz tube reactor ages ago which I packed with two flanges with aluminosilicate cement housings and cast-in smaller borosilicate tubes for inlet and outlet. If this whole apparatus was heated above 200C and the center to 600-700C, it could be used to batch produce aluminum chloride. It would exit the other tubing and sublimate into a receiving flask, which could be kept under drying tube.

A more serious device could be made with a flask with gas inlet and outlet, the system kept in housing that is heated above 200C at all times, and the flask itself kept at 600-700C holding molten Al and Cl2 lead in. AlCl3 would sublime away through the exit tube and sublimate to the receiving vessel. If excess chlorine were to vent, it could be exhausted properly through a drying tube.

Opylation - 29-6-2020 at 20:44

I’ve been curious as to if loss of the alcl3 can be mitigated using anhydrous ethanol or methanol. Per US1647446A, the patent states that solvents can be used to suppress the powder alcl3

A787867A-954D-4E49-B09E-D3BE2C999113.png - 65kB

I’ve been finding a mix of information. Some sources say that ethanol reacts with alcl3 at room temperature. I can’t find anything about the recovery of alcl3 from anhydrous solutions of ethanol

[Edited on 30-6-2020 by Opylation]

Metacelsus - 30-6-2020 at 05:27

The ethanol will react with the AlCl3, since AlCl3 is a very strong Lewis acid. The final products will likely be ethyl chloride and aluminum oxychlorides.

JJay - 30-6-2020 at 08:30

I have made small amounts of aluminum chloride from hydrogen chloride and aluminum in a quartz tube. I never managed to make very much of it that way due to flaws in my equipment that I wasn't aware of and also my relative lack of skill at the time. I was not exactly unskilled, but I had never used such a complex piece of apparatus before, and the experience of actually doing things like gas drying and temperature control was fairly new to me. I had one run that resulted in maybe half a gram of apparently fairly pure product and another run that was too hot that resulted in a lot of unreacted aluminum getting into the product (which was a few grams). Both times I had hydrogen chloride leaking from a completely invisible pinhole in one of my pieces of equipment.

The major advantage of hydrogen chloride over chlorine, of course, is that hydrogen chloride is much less toxic. A disadvantage is that the apparatus will generate hydrogen. Hydrogen can drive air out of the apparatus, but it's also extremely flammable, especially at 700 C, so several precautions must be taken.

I think it would be practical for a skilled chemist to make hundreds of grams of aluminum chloride that way with good equipment.



[Edited on 30-6-2020 by JJay]

aab18011 - 6-7-2020 at 18:50

I just completed a successful reaction of Aluminum with Chlorine gas. The first go-around worked but got ruined due to blowback from the chlorine trap. The second go worked but was ruined because I did not continue the chlorine generation. The third and final go worked perfectly.

I started by getting a chlorine generator ready, hooked it up with a short path condenser, and had it empty into a flask with small chips of aluminum foil. The vacuum adapter was then hooked up to a base scrubber to capture excess Cl2 gas. The aluminum was heated with a large propane torch set to almost closed (very weak stream, lower temp), which equated to roughly 700 degrees celsius. It was held away from glass (I have broken so many flasks because of heat shock) and slowly warmed. When it was too hot to touch, I then heated it much more rapidly and waited until I saw reddish-pink coloring of the glass. I stopped and shook the flask as best I could, and within seconds, it flashed and rapidly sublime out white substance. Once settled, it was exactly the consistency expected from the literature. I am very surprised I did not break my glassware during this reaction. That propane torch can reach 2000C if I opened it to full.

I must note that there should be catalyst added in future to help heat and begin the reaction. I have read about FeO2/CuCl2 mixture, like a powder that can be mixed. I will probably invest in a coffee grinder to help increase the surface area of the aluminum. If I was to require more however, more than 5-10g, then I would use some of the methods already posted here, as they seem to be geared towards larger amounts. Quartz tube was suggested, and maybe a doped quartz wool (FeCu/C) would be nice. Maybe a Fe-Fe(CN)6 complex would work?

alcl3-sublime-h2o-impurity_yellow.jpg - 69kB

alcl3-sublime-h2o-impurity_yellow.jpg - 64kB

clearly_not_atara - 7-7-2020 at 07:46

So apparently CuCl2 produces too much heat when you use it? We switched to ZnCl2 for this reason?

MnCl2 can be dried by heating and should give a less exothermic process than CuCl2 while being easier to make than ZnCl2. Just a thought.

JJay - 7-7-2020 at 09:28

It's probably possible to get Al-CuCl2 to work to produce useful amounts of AlCl3, but as far as I am aware, no one has worked out all of the details yet. There have been a few attempts. When the reactants are dry and finely powdered, the reaction is extremely vigorous, like setting a flame to gunpowder. When the aluminum is in coarse granules, continuous application of a propane torch is necessary to sustain the reaction.

A prominent member of this forum mentioned in the exotic thermites section some results from wrapping copper (ii) chloride in aluminum foil.

MnCl2 is an interesting idea... MnCl2 and Al melt at about the same temperature....

Mateo_swe - 7-7-2020 at 09:52

Doesnt the chlorine generator and quartz tube with al-foil procedure work ok?
Below is a procedure i saved from somewhere.
I add a pdf with another variant that i also found somewhere.

Concentrated (37%) hydrochloric acid (20 mL, 658 mmol) was added dropwise to hydrated calcium hypochlorite (22.0 g, 102 mmol) generating a steady stream of chlorine gas.
The chlorine gas was passed through a glass column filled with aluminium foil (1.00 g, 37.1 mmol) and then into a water trap. Once the apparatus had been filled with chlorine gas the aluminium foil was heated with a bunsen burner to facilitate the reaction. Upon sufficient heating, the aluminium foil burnt with a bright white light signifying the reaction had commenced.
At this point the bunsen burner was removed and the reaction self propagated along the column with occasional flickers of red-orange embers. When the vigorous reaction had subsided, a black residue remained in the column and a yellow powder (AlCl3) was deposited in the receiving flask.
Yield: 4.05 g (82%).

Attachment: Preparation of aluminum chloride.pdf (160kB)
This file has been downloaded 169 times

clearly_not_atara - 7-7-2020 at 09:54

Another approach would be to dissolve CuCl in acetonitrile... obviously you get half the molar yield vs the dichloride but the whole reaction is "cool" and liquid-phase, CuCl doesn't even form hydrates, and the solubility of CuCl in MeCN is apparently 20%:

https://www.researchgate.net/post/Solvent_to_dissolve_Copper...

Unfortunately the solution of CuCl in MeCN is unstable to aerobic oxidation, but this occurs slowly so just prepare it immediately when needed for use. It should be easy to recover the copper this way so the process can be repeated.

aab18011 - 7-7-2020 at 10:46

Quote: Originally posted by Mateo_swe  
Doesnt the chlorine generator and quartz tube with al-foil procedure work ok?
Below is a procedure i saved from somewhere.
I add a pdf with another variant that i also found somewhere.

Concentrated (37%) hydrochloric acid (20 mL, 658 mmol) was added dropwise to hydrated calcium hypochlorite (22.0 g, 102 mmol) generating a steady stream of chlorine gas.
The chlorine gas was passed through a glass column filled with aluminium foil (1.00 g, 37.1 mmol) and then into a water trap. Once the apparatus had been filled with chlorine gas the aluminium foil was heated with a bunsen burner to facilitate the reaction. Upon sufficient heating, the aluminium foil burnt with a bright white light signifying the reaction had commenced.
At this point the bunsen burner was removed and the reaction self propagated along the column with occasional flickers of red-orange embers. When the vigorous reaction had subsided, a black residue remained in the column and a yellow powder (AlCl3) was deposited in the receiving flask.
Yield: 4.05 g (82%).



I think I will try this one today and swap the quartz with my cheapo glass. I have gotten the cheap glass to work, but only on hot days and with low humidity. Also, I thought it was yellow because of Fe impurity?

Mateo_swe - 7-7-2020 at 20:52

Good luck.
Dont put too much Al-foil in the glass tube as the produced AlCl3 can block the tube.
If that happens the chlorine gas will need to find another way out of the device.
Do it outside or if you have a flowhood.
I will also try this when my ordered quartz tubes arrives.
In the pdf variant they bubble the chlorine gas through 2 flasks before going into the glass tube with Al-foil.
The first with water to remove any HCL in the chlorine gas and the second with some conc. sulfuric acid to dry the chlorine gas.
I dont know how much this will improve things, but skipping this will obviously work also.
Maybe if you need high purity AlCl3 its something to consider.

[Edited on 2020-7-8 by Mateo_swe]

aab18011 - 7-7-2020 at 21:01

Decided I am going to wait one more day. Tonight I prepped the chlorine, the sulfuric acid scrub, and I prepared a small 25mL flask. The hope is to load about .01g of Aluminum after its been cleaned, dried, and slightly warmed to evaporate any weird stuff. At about 7am, Ill rerun the reaction.

PS... does anyone have any clue what that black solid might be in the pictures above? The reaction auto-ignited and flew up the neck of the flask but quickly turned black from a white substance. Some of it turned yellow, but I'm not sure why. I had not run a iron reaction before in that flask. As far as I know, the only things in the flask were HCl gas, Cl2 gas, and the Aluminum.

aab18011 - 9-7-2020 at 17:16

Okay, so that was a total failure. I tried three times again, and each time I was much too impatient and hasty. I heated the aluminum for away too long after the autoignition. However, had I successfully heated it properly, I would have attained beautiful yellow powder. Next time, sometime next week probably, I will work on a slower workup.

I think I am going to try ordering some catalysts, my professor from the Inorganic class said that Fe2O3 and CoCO3 are good to throw in. But everything needs to be fairly grinded. I suggest that anyone else use the powdered aluminum as it is easier to ignite. Only warning is that it is much quicker and needs to be done in a larger tube or container.

Mateo_swe - 11-7-2020 at 03:36

The more solid the Al is the slower the reaction is going to be.
I would use a larger diameter tube if using thin or powdered Al, so it doesnt get blocked.
Maybe do a small test with not so much Al first to get a feel how fast the reaction is.

aab18011 - 12-7-2020 at 15:49

Thats a good idea M... I am going to set up a gas adapter to my test tube and put one solid piece of foil in there, probably semi wound into a roll. Im not sure how much chlorine will be since my scale has broken, but I will make excess and add a air trap determine the usage of gas. I also heard that putting carbon inside the reaction chamber may increase the efficiency; came from the last inorganic lecture I sat in before the virus hit. If I recall correctly, the professor said that activated carbon could help homolytically cleave the Cl2 bond forming 2 radicals...

Anyone know if this claim holds any water?