swicr is a hardcore total synthesis fan so HgCl2 is kinda out of the question for amalgamations but theres a thread on rhodiums archive that describes a Hg2Cl2 synthesis that doesn't sound to bad. so the question is from a practical stand point, can mercurous chloride be used in an amalgamation for A/MDA from eachs respectable ketones? It understands the solubility issue but it seems that with enough aggitation the reaction would kick off.   

thanx! swicr also asked about hcl on mercury which It thought would lead to a mix of Hg2Cl2/HgCl2 and hydrogen gas evolution. is that what was meant in the above reply?

Illustrative only.


 
Abstract of  GB 1436733 

 Activated aluminium is prepared by contacting aluminium of at least 99% purity with liquid Hg, Ga or In-Ga alloys in the presence of a liquid source of protons covering the aluminium so that the liquid metal diffuses into the aluminium. The preferred proton source is an aqueous solution of HCl with a pH of 0.2-4 and in an example 100g. of a " diameter aluminium rod 99.99% purity is placed in 2g. Hg and covered with HCl pH 4. The activated aluminium is washed with hot water or dipped in anhydrous methyl alcohol. The activated aluminium is used in the preparation of aluminium carboxylic acid compounds by reaction with carboxylic acid as disclosed in Specification 1436732.

Amalgums can also be formed by adding elemental mercury to an aluminium salt. So thay say.
Someone once tried adding some muriatic acid to some alfoil and evaporating to dryness.To the grey/white powder was addedd a drop of mercury,after leaving for a few days most of it had turned to a bright yellow efflorescent compound which was then disposed of in a responsible maner.

This is the first of many to come experiments dealing with total synthesis of Cl salts of Hg for use in amalgams.

Experiment 1: oxidation of elemental Hg--->chlorination of Hg oxide(s) to the corresponding salt(s)
To a glass vessel large enough to maximize Hg surface area was added 10 g of Hg (appears to be relatively pure) then said vessel was charged with O2 from a torch tank. The vessel was then capped and stored in a cool (68-70deg F) place. This will be observed daily and updated when neccesary.

If you want the oxides then perhaps H2O2 or some other oxidiser other then O2 would work better.

I have tried using HCl + 30% H2O2 on mercury before since it attacks most other metals quite readily. I had no luck with this mixture; perhaps heating or more concentrated H2O2 would do the job, but if catalytic decomposition starts I wouldn't want mercury-compound-laden steam and spatter shooting out of the reaction vessel. It will be interesting if neutral H2O2 works better.

HCl + a little ammonium nitrate works nicely; other nitrates would probably work too. It's a poor man's aqua regia, essentially. Just keep the mixture in a warm room and the mercury will dissolve over the course of a day or two (talking about 1-2 g Hg in a test tube). The resulting liquid is still quite acidic, of course. This actually helps a little to start amalgamations on unclean metal if you add the acidic mercury solution to a larger volume of water containing your aluminum or other metal. You may be able to reduce acidity somewhat by using a large excess of mercury and letting the mixture stand for a long time, later pipetting the solution off the excess mercury when needed.

I would not try to get crystals from the solution. As said before, some HgCl2 will be lost if you try to heat the solution to dryness, and that's a waste and a health hazard. Further, HgCl2 crystals (at least the lab grade I'm familiar with) are actually kind of a pain to dissolve in aqueous solution again. They want to float on the surface like little bits of sawdust instead of sinking and dissolving right away. If you carefully track the quantities of mercury and acid you use to prepare your solution with HCl and nitrate, you should be able to dispense the needed quantity of mercury by adding a measured volume of solution. It will mix instantly with other liquids and you never have to risk mercury volatilization by heating the mix. If you're concerned about residual acidity interfering by e.g. binding too much amine in a useless form, you should be able to titrate an aliquot of the liquid to determine acidity and then add a slight deficit of sodium bicarbonate or the like to the main batch so that the liquid remains only faintly acid. Alkali metal cations should be mere spectators in most situations that call for amalgams.

It can be used without a doubt but like ya said solubility is suppose to be an issue. Any Hg salt will work and even Elemental Mercury can be used as long as it forms the amalgum. I personaly wish this form of reductive amination would take a long walk off of a short pier due to its toxicity and volitility(you'll see) but as it stands its about the best we got as far as access is concerned.

I have always just heated Hg in H₂SO₄ and recovered the sulfate then reacted that with HCl which works well enough. Care must be taken because if you look for a thread on here by Poisioninthestain you will see where I discussed the salt evaporating off into the room as you concentrate the solution. I did this at very lo temperature and it still made its way out of the container.

Try mercury nitrate. Mix NaNO3/H2SO4 and Hg and allow it to consume the Hg. This can be used for the amalgum as I understand it.

I don't believe that would work very well as the sulfate ions would precipitate insoluble HgSO4. Best to use HCl.

Mercury (II) Chloride, mercuric chloride, HgCl2. Direct combination reaction with mercury + cold dry chlorine, Cl2, gas bubbled into the mercury. Mercury (II) Chloride is soluble in water, so separation of unreacted mercury is simple.

Chlorine gas http://en.wikipedia.org/wiki/Chlorine#Production


Mercury (I) Chloride, mercurous chloride, Hg2Cl2. Add dilute HCl to a Mercury (I) salt solution.

That's why I'm surprised that H2O2 and HCl do not attack Hg, as the peroxide is supposed to oxidize the HCl in the following manner: 2HCl + H2O2 --> Cl2 + 2H2O.

HCl passifys Hg IIRC yet nitric being an oxidising acid wont have that problem. The main goal is just to use nitric acid on Hg to make the nitrate of Hg. A few have had nice results doing exactly what i stated without the precipitation issue you mentioned but I have no first hand experiance.

I am in the midst of cleaning up so as soon as thats done I will no doubt perform this experiment with the quickness and well document if with pictures even though I hate Hg completely.