Sciencemadness Discussion Board

Zinc in organic chemistry -- why always the chloride salt?

SnailsAttack - 19-4-2022 at 17:19

If you go to the wikipedia page for salts of zinc such as the sulphate and acetate, you won't find much regarding their uses. If you go to the page for zinc chloride however, there's about a bajillion different applications given.

Is it something to do with how zinc chloride is a Lewis acid and apparently forms a ton of different aqueous complexes?

Also, would the sulphate and acetate salts be at all effective in the applications described such as in disinfectants, wood preservatives, dissolution of cellulose, smoke grenades, etc


clearly_not_atara - 19-4-2022 at 18:16

Disinfectants and wood preserving are biological applications. We don't know anything about that kind of stuff :D

I'd guess that other zinc salts are perfectly good disinfectants. The chloride is probably just cheaper. The sulfate will not be as effective in smoke grenades; the acetate could probably work, but it's also flammable, which is bad. I am not sure about cellulose dissolution but I think this relies on the strong Bronsted acidity of ZnCl2 solutions as well as the complexing effect of zinc ion, so I think neither acetate nor sulfate works.

For most chemical applications the sulfate will not do because it is not soluble and the acetate, as you mentioned, is not as strong of a Lewis acid. ZnCl2 has some covalent character that makes it behave more like a molecule in organic solvents.