THE MOLECULAR AND ELECTRONIC-STRUCTURES OF IONS AND RADICALS DERIVED FROM TETRAMETHYLLEAD, HEXAMETHYLDILEAD, DIMETHYLLEAD, AND TETRAMETHYLDILEAD - AN SCF-MO STUDY

Molecular geometries and energies have been calculated, using the semi-emperical MNDO method for closed shell species, and the UHF-MNDO method for neutral radicals and cation radicals for PbMe4, Pb2Me6, PbMe2, and three isomeric forms of Ph2Me4 and all of their cation radicals, together with fragment ions and radicals including (PbMe3+, PbMe3, and (Pb2Mex)+ for 1 ≤ x ≤ 5. The radical cation (PbMe4)+ is calculated to have C3v skeletal symmetry, with a D2d isomer some 26 kJ mol-1 higher in energy: the dinuclear cation radical (Pb2Me6)+ is calculated to be a σ(PbPb) radical of D3d skeletal symmetry. The mass spectral fragmentations of both PbMe4 and Pb2Me6 are discussed. © 1990.