Gd. Perekhodtsev et Ys. Lebedev, EXCHANGE INTERACTIONS IN BIRADICAL COMPLEXES OF METALS(II) WITH O-SEMIQUINONES - PM3 CALCULATION, Journal of structural chemistry, 38(1), 1997, pp. 41-46
The energies of singlet-triplet splittings in different configurations
of biradical complexes of bivalent metals Mg, Zn, Cd, and Hg with o-s
emiquinones are calculated semiempirically (by the PM3 method taking i
nto account the configuration interaction). The calculated values are
consistent with the qualitative theoretical predictions. The calculati
ons suggest that the multiplicities of the ground states of the above
complexes are determined mainly by the superexchange through the unocc
upied p-orbitals of the central metal ion.