Trithioarsenite, also called sulfarsenite, is the trianion . It is a pyramidal anion, as is typical of other compounds. It is generated by treatment of with a sulfide:
A fundamental synthetic trithioarsenite is , which features the pyramidal .
Thioarsenites are components of many sulfosalt minerals. An example is relatively common mineral proustite, ,MindatWebmineralTrevelyan B. 1969: The electro-optic effect in proustite. Optical and Quantum Electronics, 1(1), pp. 1969; which is silver(I) trithioarsenite.
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