Chalcogenidometalates of the heavier Group 14 and 15 elements

The review covers structural aspects of the chemistry of ternary and quaternary chalcogenidometalates of the heavier Group 14 (Ge, Sn, Ph) and 15 (As, Sb, Bi) elements, with particular emphasis being placed on polymeric anionic networks, Technological interest in the design of nanoporous materials with tailor-made properties has stimulated recent research into intermediate-temperature solid-state synthetic methods (e,g. molten flux and solventothermal techniques) for the construction of lamellar and framework anions of this type, Under these relatively mild conditions (T = 100-600 degrees C), intact molecular building blocks such as rings and chains can self-organize to a fascinating variety of polyanions, whose dimensionality and cavity/channel size can be influenced by the choice of suitable structure-directing agents such as alkali metal or alkylammonium cations. Classification of the resultant chalcogenidometalates in this review is therefore performed in terms of both the nuclearity y of the component MyEz building units (M = Group 14 or 15 element, E = S, Se or Te) and the dimensionality d of the anion network, Promising novel multifunctional materials, that combine the typical exchange and catalytic features of zeolite-like phases with the unique optoelectronic properties of Group 14/15 chalcogenides, are presented. (C) 1998 EIsevier Science S.A. All rights reserved.