Microporous Metal Chalcogenides

Recently it has been found that the reaction of tin, antimony and germanium with sulfur in the presence of organic templates under hydrothermal conditions produces a novel class of microporous metal sulfides. Such a compound, (NMe4)2Sn3S7.H2O is shown The structure consists of Sn3S72- layers separated by (NMe4) + cations. Within each layer there are holes formed by twelve Sn-S polyhedra. Six M3S4 semi-cubes are bridged by two sulfurs to form the ring. These kind of tin-sulfur linkages have been found to be very flexible and a variety of structures have been formed using different templates. Their microporous nature should lead to interesting host-guest chemistry as is observed for zeolites. However, in contrast to zeolites which are insulators these materials are semi-conductors.

a) view down the 100 axis showing the tin-sulfur rings b) view down the 010 axis showing the layer structure