Solvothermal Syntheses and Characterizations of Four Quaternary Copper Sulfides BaCuMS (M = In, Ga) and BaCuMS (M = Sn, Ge).

Hydro(solvo)thermal syntheses of quaternary copper sulfides containing alkaline earth metal ions remain a great challenge because of the low solubility of Cu-S compounds. Herein, a new facile solvothermal method was developed, and four quaternary copper sulfides, i.e., BaCuInS (), BaCuGaS (), BaCuSnS (), and BaCuGeS (), were prepared using excess sulfur as a mineralizer. Compound possesses a novel three-dimensional (3D) anionic [CuInS] framework constructed by an 8-membered ring of [CuS] and [CuInS] alternatively. Compound features a unique 3D anionic [CuGaS] framework composed of [CuGaS] anionic chains and 8-membered rings, in which [CuS] and [CuGaS] reside alternatively. Compounds and feature 3D anionic [CuMS] (M = Sn, Ge) frameworks composed of CuS and MS tetrahedra with Ba located in the channels. It is worth noting that different 3D Cu-S frameworks exist in the title crystal structures, in which main group ions are incorporated. This paper provides a new synthetic strategy for new quaternary sulfides.