Thallium Arsenide

The freezing point curve of the thallium-arsenic system was investigated by Mansuri, who was unable to isolate any definite arsenide. The two elements alloy in all proportions, but do not react chemically with each other and do not form any solid solutions. By fusing together thallium and arsenic in suitable proportions, Carstanjen obtained a white crystalline mass which he considered to be the arsenide Tl₂As. The product was soft enough to be cut with a knife. It acquired a yellow tinge when exposed to the air, and was readily decomposed by cold acids, arsine being evolved.