Theoretical study on magneto-structural correlation of trinuclear copper (II) complex with the hydroxo bridge and bidentate syn-syn carboxylate group

The theoretical study on magneto- structural correlation in linear trinuclear Cu (II) com- plex bridged by hydroxo group and bidentate formato group has been performed using the broken symme- try approach with the framework of density functional theory (DFT-BS). The magnetic coupling constant for the model complex is 70.97 cm?1, comparable with the experimentally measured J value (77 cm?1). The calculated results show that the magnetic coupling interaction firstly slightly increases with the changes of the coordination environment around the terminal Cu atoms from a distorted square pyramid to a trigonal bi-pyramid, and decreases subsequently. In the course of changes, the sign of J value shifts from positive to negative. The magnetic coupling interac- tion is sensitive to coordination environment of the terminal Cu. The calculated results also reveal that the ferromagnetic coupling arises from the counter- complementarity of the hydroxo and formato bridges. Molecular orbital analysis validates the conclusion.

The theoretical study on magnetostructural correlation in linear trinuclear Cu （Ⅱ） complex bridged by hydroxo group and bidentate formato group has been performed using the broken symmetry approach with the framework of density functional theory （DFT-BS）. The magnetic coupling constant for the model complex is 70.97 cm^-1, comparable with the experimentally measured J value （77 cm^-1）. The calculated results show that the magnetic coupling interaction firstly slightly increases with the changes of the coordination environment around the terminal Cu atoms from a distorted square pyramid to a trigonal bi-pyramid, and decreases subsequently. In the course of changes, the sign of J value shifts from positive to negative. The magnetic coupling interaction is sensitive to coordination environment of the terminal Cu. The calculated results also reveal that the ferromagnetic coupling arises from the countercomplementarity of the hydroxo and formato bridges. Molecular orbital analysis validates the conclusion.