Hg2Cl2 -> HgCl2

I have some Mercury (I) Chloride that I am interested in turning into Mercury (II) Chloride. Hg2Cl2 -> HgCl2.

From what little I have researched so far, I have found that passing chlorine gas through Hg2Cl2 or through Hg itself can produce it, however I am not ready to just "willy nilly" start mixing my Hg2Cl2 or pure Hg with appropriate solvents and running Cl2 through them hoping for the best.

I am aware of its toxicity, and that is why I am asking here for those that may have personally performed this synthesis, as I have no intention to attempt it without tons more research.

I do not want to be spoon fed here, and I have UTFSE. I can easily purchase this reagent but it is rather expensive because of hazardous shipping fees, and if there is a safe (experienced wise) way to synthesize it in the lab in small amounts then I would be interested in feedback. Besides, I have always been more interested in chemical synthesis than through just purchasing the reagents wholesale.

I am only looking to synthesize at the most .5-2g of this for the time being as I treat all Hg compounds, especially salts of Hg with the utmost respect. HgCl2 is especially water soluble and therefore even more dangerous than the mercurous chloride that I currently have on shelf with only .2mg/100ml H20 solubility.

I also have experience with drying and using Cl gas in my lab for those that want to warn me of the potential toxicity of chlorine, of which I have intimate knowledge of

Thanks for any feedback.



[Edited on 3-6-2013 by zenosx]

glitch sorry ,, hit return too fast

Ah well, I'll hit the lab tomorrow with what I have so far. If I get any results worth posting I will let you guys know what results I have.

My first is that elemental scientific sent me mercurous (I) chloride but listed the structure as HgCl2 on the bottle which would be mercuric (II) chloride, a much more dangerous and water soluble compound that I would prefer to have to work with.

I will start with solubility tests to verify what in fact I was supplied with.

I will say it is rather odd that the fellow wanting to synthesize dimethyl mercury got more feedback hehe Maybe it's just because that is a rather stupid thing to do, unless you enjoy permanent neurological damage and death

Thanks guys, yes I understand that this chemically is a very simple reaction. Elementary in fact. I did do the out of site research and understand the mechanics behind the reaction, and ways to the end material.

I should have clarified that I was looking to do this in a way that would not expose me to any more Hg than necessary (EG: None . Mainly asking if anyone else had performed this reaction in person rather than through just theoretical means or through thought experiments.

I do not have a capable fume hood ATM and just working in outside conditions do not necessarily make reactions such as these safe. As such, while the UV method is great, there is a high amount of contamination and Hg vapor released from this process unless a specialized chamber where to be built which I have no want to do as I can just purchase this compound much easier than producing it in that case.

I had hoped to hit the lab today but was unable to, perhaps Thursday I will be able to and as mentioned will report results.

As I mentioned, this was purchased as mercurous (I) chloride from elemental scientific but the bottle lists another compound in the formula, EG: mercuric (II) chloride.

This is a very small but important difference in the compounds as far as solubility and toxicity.

Thanks for the feedback. I will report my methods and results within a week for any interested.

EDIT: I went down to test the compound I have to the disapproval of my other half and did in fact find that I have Hg2Cl2 from H2O solubility tests.
.225 g added to 6.25mL of H2O offered no visible solubility and after raising the temp on the hot plate to H2O boiling, there was no noticeable dissolution of the initial .225g charge in the beaker (10mL beaker).

So from here out I can at least work knowing that the HgCl2 from elemental scientific is in fact Hg2Cl2

[Edited on 5-6-2013 by zenosx]

[Edited on 5-6-2013 by zenosx]

Finally completed this experiment (Almost)

After reading more UTFSE and others attempts at a sulfate route and no one attempting the UV route I seen on a quick browse, and the fact that I never even replied back to my own thread, this is my attempt at using Cl¬2 to convert Hg2Cl2 (Mercurous Chloride, Mercury (I) Chloride) to HgCl¬2 (Mercuric Chloride or Mercury (II) Chloride) from Cl¬2 exposure. This was purely done for my personal experimental research as I had nothing else planned and was highly curious if I could in fact complete this synthesis.
While I have not yet finished yield calculations being that my scale is dead atm and the final product is still in the desiccator, I found my initial results promising enough to at least post visuals for the experiment. While I am not sure on the exact requirements of a micro-scale experiment, this would be very close to one I imagine as I did not want to start off with multi-gram quantities of a mercury salt and liters of Cl2 gas in my lab and only 250mg or so of starting material was used.
To start with the below rather simple apparatus was constructed consisting of a Cl2 generator using 15% HCL in the addition funnel to a lower bulb of NaOCL of 10% concentration. The resulting Cl2 was not dried since an aqueous solution would directly follow. The Cl2 was led into a 2 neck `20mL flask through PCV tubing and a pasteur pipette. Exit gasses were led into the Erlenmeyer flask with a bubbler tube running through NaOH. To the reaction flask approx. 250 mg of Hg2Cl2 was added with the pipette leading to the bottom of the conical flask with the powder on top.
The apparatus was initially run dry with just Cl2 passing through the Hg2Cl2 powder. To this DI water was later added with additional Cl2 bubbled through it. Unfortunately due to my own ineptitude I have not accurately calculated the amount of Cl2 that was created, however if someone wants to do the math, around 50mL of NaOCL to an amount of 15% HCl equivalent to not produce any more Cl2 was used. In hindsight, this would be a very useful quantity to have written down, but this experiment was carried out over a period of a month between homework and my upcoming wedding so that is my excuse . Using the above I will eventually calculate the full amount for my lab notebook.
All photos were taken with my iPhone so apologies on the low quality.

Initial apparatus



Cl2 Generation



Close-Up of the reaction flask
(Not Shown – Aqueous Cl2 bubbling)





Aqueous Solution after reaction and before filtration





The aqueous suspension was then vacuum filtered and the recovered unreacted material collected from the filter paper (not yet weighed for above reason). The remaining supernant was then heated reducing the around 15mL of material to `4mL and was then allowed to cool and sit undisturbed overnight.
(NOTE: For those about to ask, the supernant was completely clear and devoid of any non-soluble salts before allowing to cool and evap. Before leaving to cool and evap the solution was still clear and did not show any crystals while hot which to me excludes any starting material from the below beaker.)
Upon returning the next day the following beaker of crystals of highly soluble (Hopefully) HgCl2 resulted. I have not yet had time to weight or test solubility or melting point of the resulting crystals as they are still drying and my scale is still dead.

Crystals after sitting overnight







(Note, no I am not wearing gloves but this was only picked up long enough to photograph and no attempt was made to touch, eat or otherwise expose myself to this highly toxic salt…)

Just judging with my eyes between what was recovered of the initial material vs. what was collected I estimate around 40-60% yield which isn’t too bad considering.
If anyone shows any interest I will (when I have time in my very busy schedule) post more detailed numbers on the starting material vs. theoretical and actual yield. Note that it did take me like 2 months to even post back to my own thread to give an idea of just how little time I have to donate to the lab (much to my own dismay). Also, I do not currently own a scale that is accurate to much less than 200mg so these small amounts may be unable to be weighed accurately.

I don't really have much to add, but I wanted to at least show support of your project. Nicely done! Very creative setup. Did you have any suckback prevention measures? I didn't see an intermediate wash bottle. Every time I do an experiment involving gas generation it sucks back on me
I am eager to see if it succeeded, and what your yields were. Solubility would be one way to differentiate, but is there a more definitive test for Hg²⁺ vs. Hg¹⁺? Also even though you weren't planning on touching it, I'd still at minimum wear gloves 100% of the time when around such a compound. You never know when a spill is going to happen!

TLDR;
The initial yield is 33.4%
Starting material = `600mg
Ending Product = ` 200mg

Ok, first, I tried to update the post with amounts but apparently the thunderstorm killed my post before it was uploaded.

To the replies;
No, I did not have any suck-back issues as the Cl2 generation was closely monitored and no wash bottle was used to dry the Cl2 since an aqueous solution was to follow at the end of the Cl2 exposure. The pipette was so exposed that I could easily pull it from the layer of H20 if the Cl2 production slowed down, however this did not present a problem as the Cl2 was kept at a rather standard rate throughout and the pipette pulled from the reaction vessel when Cl2 production slowed.

The exit from the reaction vessel always flowed into a NaOH wash bottle to reduce or eliminate Cl2 gas output to the lab.

If you can see from the photo's, the pipette was wrapped in PTFE tape to the extent that allowed me to move it rather freely from the bottom of the reaction vessel to almost pulling it free during the experiment.

1) Yes, handling any mercuric compound without gloves is never smart, I took a calculated risk based upon the small amount of materials vs the close proximity to the lab bench to negate as much exposure hazard as possible.

2.) Unfortunately I posted this in my excitement of a successful yield but before calculations. The NaOCl flask was changed out 5 times during the experiment run as well as the HCl addition funnel.

3 I attempted to edit this post to update the incorrect data but for some reason it didn't go through, possibly from the thunderstorm that killed my internet throughout the day.

Anyhow, I am working out the math ATM, but much more Cl2 was passed over the sample as previously mentioned as well as the sample being around 600mg, not 200mg as initially stated. I was working off of two notebooks, not to mention the 2 months this experiment took and jumped the gun on this post so I apologize.

I will work out the exact math and equations to post back on this post ASAP. My next college quarter starts Friday so I apologize if it takes me longer than expected but I fully plan to post the exact mole to product equations.

Sorry for the sloppy post, but again, in my excitement to have any yield on this month long experiment I just jumped the gun

Thanks for those that bothered to read my long post and point out the inaccuracies in them

zenosx, could you perform this reaction in this manner, but replace Hg2Cl2 for elemental Hg to yield HgCl2? Is there a proper thread on this particular reaction?

Nice rig btw

[Edited on 4/16/2014 by HoH]