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.