The First Nitride Spinels-New Synthetic Approaches to Binary Group 14 Nitrides.

A significant breakthrough in the nitride chemistry of main group elements has been achieved: Surprisingly Sn(3)N(4), for which there had been no proof of existence until now, as well as the isotypic high-pressure polymorphs gamma-Si(3)N(4) and gamma-Ge(3)N(4) have been synthesized. All three compounds crystallize in a spinel structure type (see picture) that previously has not been found for nitrides, and may have a high relevance for practical applications in the context of ultrahard materials.