Orbitals in inorganic chemistry: metal rings and clusters, hydronitrogens, and heterocyles

A chemical orbital theory is useful in inorganic chemistry. Some applications are described for understanding and designing of inorganic molecules. Among the topics included are: (1) valence electron rules to predict stabilities of three- and four-membered ring metals and for those of regular octahedral M(6) metal clusters solely by counting the number of valence electrons; (2) pentagon stability (stability of five- relative to six-membered rings in some classes of molecules), predicted and applied for understanding and designing saturated molecules of group XV elements; (3) properties of unsaturated hydronitrogens N( m )H( n ) in contrast to those of hydrocarbons C( m )H( n ); (4) unusually short nonbonded distances between metal atoms in cyclic molecules.