Layered Phosphates, Phosphites and Phosphonates of Groups 4 and 14 Metals

Abstract

Abstract Research dealing with the ion exchange behavior of layered group 4 phosphates dates from World War II. Initially the exchangers were amorphous gels in which the exchange process was poorly understood. Crystallization of the gels and the subsequent determination of their crystal structures had led to an understanding of the ion exchange reactions. The most important group of exchangers have layered structures and can readily intercalate basic molecules in addition to exchanging ions. Their behavior can be used as the basis for understanding the properties of many proton containing layered compounds. The chemistry of these compounds has had a continuous growth in scope, particularly with the synthesis of organic-inorganic layered derivatives. Extension of this organic chemistry to divalent and trivalent metals further broadens the field. Potential applications as sequestrants, ion exchangers, catalysts, sensors and their possible use in the fields of electrochemistry and photochemistry are discussed.