MO THEORETICAL-STUDY ON THE DICATIONS OF TETRASULFUR, TETRASELENIUM, AND TETRATELLURIUM

The electronic structures and the singlet transition energies of the title compounds are studied by using semiempirical INDO-type ASMO-SCF calculations. Localized MO's of each species evaluated from the canonical MO's are also examined. According to the results, these species are all of 67π Hiickel systems, and their characteristic absorptions at the visible region can be assigned as the highest occupied MO (π) the lowest unoccupied MO (π*) transitions. The electronic structures of Te42+ are rather different from those of S42+ and Se42+ because of the degrees of the contributions from s AO's to the interatomic bonds. © 1979, American Chemical Society. All rights reserved.