Electronegativity equalization and the electronic structure of polyhedral clusters of main‐group atoms

Abstract

AbstractThe concept of the equalization of atomic electronegativities accompanving molecule formation is applied to a study of the electronic structure of polyhedral clusters of main‐group atoms such as Ge, Sn, Pb, Tl, and Bi. Emphasis is placed upon charged clusters such as Sn9−x Pb(x = 0 → 9), Sn9‐xGe, Sn8−xPbx Tl5−, Sn2Bi, SnTe, etc. The role of the relativistic spin‐orbit splitting of an np shell into np1/2 and np3/2 subshells in modifying atomic and hence molecular electronegativities is discussed. Correlations are made between calculated charge distributions and observed199 Sn NMR chemical shifts for clusters of a given size and charge. It is concluded that a useful picture of charge distributions in these clusters may be obtained from electronegativity equalization considerations.