Chemistry:Trithioarsenite

Subunit of the structure of proustite, a sulfosalt mineral. This picture shows the connectivity of the trithioarsenite trianion to Ag+
(arsenic is colored violet).

Trithioarsenite, also called sulfarsenite, is the trianion AsS3−
3. It is a pyramidal anion, as is typical of other AsIII
X
3 compounds. It is generated by treatment of As
2S
3 with a sulfide:

As
2S
3 + 3 S²⁻ → 2 AsS3−
3

A fundamental synthetic trithioarsenite is Na
3As
3, which features the pyramidal AsS3−
3.

Thioarsenites are components of many sulfosalt minerals. An example is relatively common mineral proustite, Ag
3AsS
3, which is silver(I) trithioarsenite.