Mg. Cory et al., CALCULATED STRUCTURES AND ELECTRONIC ABSORPTION-SPECTROSCOPY FOR MAGNESIUM PHTHALOCYANINE AND ITS ANION-RADICAL, Inorganic chemistry, 34(11), 1995, pp. 2969-2979
Structures are calculated for magnesium phthalocyanine (MgPc) and its
radical anion doublet (MgPc(-)), using both ab-initio (6-31G*) and se
miempirical (INDO/1) self-consistent field approaches. The anion is fi
rst-order Jahn-Teller distorted, and the various distortions that are
possible an examined. The electronic absorption spectra of both molecu
lar species and the effect that varying the degree of distortion has o
n the computed anion spectrum are discussed. These results suggest tha
t the four-orbital model often applied to porphyrin systems in interpr
eting the low-energy spectrum is incomplete for the anion case. We fur
ther conclude that the Jahn-Teller distortions calculated by either ab
-initio or semiempirical models may be too great.