Synthesis, Structure, and Electronic Properties of Sn9O5Cl4(CN2)2

The formation of the new compound Sn9O5Cl4(CN2)2 is reported and placed in the context of several other recently discovered tin carbodiimide compounds (Sn­(CN2), Sn2O­(CN2), and Sn4Cl2(CN2)3), all of which contain divalent tin. The crystal structure of Sn9O5Cl4(CN2)2, as determined by X-ray powder diffraction, includes an unusual [Sn8O3] cluster, in which tin atoms form the motif of a hexagonal bipyramid. An additional tin atom and two oxygen atoms connect these clusters into chains. Mössbauer spectroscopy shows tin to predominantly adopt the +2 oxidation state, and electronic structure calculations predict Sn9O5Cl4(CN2)2 to be a semiconductor.