rocketman - 19-11-2019 at 12:15
Is there an easy way to convert sulfur monochloride S2Cl2 to Selenium monochloride Se2Cl2? 
Ubya - 19-11-2019 at 12:22
are you aiming at a metathesis reaction?
[Edited on 19-11-2019 by Ubya]
DraconicAcid - 19-11-2019 at 12:44
Metathesis generally works with ionic compounds- I can't see a reaction between disulphur dichloride with selenium giving the desired product.
clearly_not_atara - 19-11-2019 at 13:22
Se2Cl2 is much easier to produce than S2Cl2 -- simply dissolving SeO2 in HCl gives some monochloride, IIRC. Unlike the sulfur compound, it is
not an effective dehydrating agent.
woelen - 21-11-2019 at 11:12
Are you sure about that? I have tried this reaction a few times, and I get a yellow solution, containing the complex SeCl6(2-).
clearly_not_atara - 21-11-2019 at 19:56
I'm afraid I'm pretty much quoting Wikipedia, which references Feher in the Handbook of Preparative Inorganic Chemistry for this:
https://en.wikipedia.org/wiki/Selenium_monochloride#Preparat...
3 Se + SeO2 + 4 HCl → 2 Se2Cl2 + H2O
Now maybe you want some other reducing agent in there, but the general idea is the same.
[Edited on 22-11-2019 by clearly_not_atara]
woelen - 22-11-2019 at 00:41
But now you are adding additional reagents. In your previous post you wrote that simply adding Seo2 to hydrochloric acid gives Se2Cl2.
I still have severe doubts. If you add a reductor like SO2 (or Na2SO3) to HCl and add SeO2 to that, then you get elemental Se.
SeO2 gives H2SeO3 and in concentrated HCl also H2[SeCl6]. SO2 is capable of reducing selenium(IV) to elemental selenium. However, when an excess
amount of SeO2 is added, I do not see any liquid of Se2Cl2, I only see the brick-red solid Se, suspended in a pale yellow solution.
AJKOER - 30-11-2019 at 04:41
A partial extract from Atomistry http://selenium.atomistry.com/selenium_monochloride.html which is, itself, an extract from 'old' chemistry journals:
"Selenium Monochloride, Se2Cl2 is most easily obtained by the action of chlorine on heated selenium, but it is always accompanied by a certain
quantity of the more stable tetrachloride which, however, is less volatile. It may be prepared by saturating with chlorine a suspension of selenium or
a selenium mineral in carbon tetrachloride. The selenium monochloride is soluble in carbon tetrachloride, whilst the chlorides of other elements
present are insoluble. The monochloride is therefore obtained by evaporation of the solvent after filtration.
The chlorides of certain non-metals such as phosphorus have a similar action on selenium, possibly on account of previous dissociation with formation
of chlorine.
.....produced when seleniferous sulphuric acid is heated with salt. On the addition of ferric chloride, the monochloride gradually separates.
A solution of selenium in fuming sulphuric acid gives a gradual separation of the monochloride on the addition of hydrogen chloride.
Selenium monochloride is a clear reddish-brown liquid of density (D25°4°) 2.7741, and can be condensed to a solid of melting-point -85° C. Its
odour somewhat resembles that of sulphur monochloride....."
My reading of the above is whatever path one selects, limit/avoid the presence of water, implying a behavior similar to sulfur chlorides.
Likely adding Se to S2Cl2 forms Se2Cl2 as, per one source https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5187540/ :
"Se is more easily oxidized than S"
[Edited on 30-11-2019 by AJKOER]