Periodic Compounds: Syntheses at High Pressures and Temperatures

Abstract

A new class of compounds, called "periodic compounds," identified by the selection rule G = Σd_ie_i/Σd_i, where G assumes the integral values 1, 2, 3, . . . corresponding to the periodic table groups I, II, III, . . ., is discussed. The number of bonding electrons contributed by an atom of kind i is designated e_i, and d_i gives the number, per formula weight, of atoms of this kind. Both e_i and d_i assume integral values. Periodic compounds consist of symmetrical and unsymmetrical types. The recent synthesis of the unsymmetrical periodic compound B₂O, an isoelectronic analog of carbon, suggests that many more unsymmetrical types may be amenable to synthesis, particularly by high-pressure and high-temperature techniques.