Charge distribution in Mn(salen) complexes

The charge and spin distribution in manganese-salen complexes were analyzed using different basis sets and density functionals. Five population analysis methods [Mulliken, Lowdin, Natural population analysis (NPA), atoms in molecules (AIM), and CHelpG] were used to characterize the charge distribution. Results show that NPA and AIM were the only methods capable of giving charges with the correct sign for all cases under study. According to the analysis of the natural charge and spin distributions, the salen ligand shows a complex behavior, counteracting the effect of the chloro and oxo ligands on the metal center. Furthermore, the presence of a chloride counter ion increases the oxo-radical character of Oxo-Mn(salen) complexes, which may play an important role in the rationalization of the catalytic properties of Mn(salen) complexes. © 2014 Wiley Periodicals, Inc.