From antiferromagnetic to ferromagnetic exchange in a family of phenoxido-bridged heterodinuclear Cu(II)-Mn(II) complexes: A magneto-structural theoretical study

Abstract

Density functional theory with a broken symmetry approach was performed on phenoxido-bridged heterodinuclear complexes [LCuMn(NO3)2], for which magneto-structural correlations were developed. Satisfactory results were obtained at the B3LYP*/TZV level, and the calculated J value of the magnetic coupling constant was − 35.24 cm−1, which is consistent with the experimental result of − 35.80 cm−1. The analysis of spin populations indicated that the paramagnetic centers Cu(II) and Mn(II) exhibit a spin delocalization mechanism. The study of magneto-structural correlations indicated that the magnetic coupling constant J value shows a linear correlation with the bond angle (θ) of Cu–O-Mn; for θ < 97.20°, the magnetic coupling effect between Cu(II) and Mn(II) transformed from an anti-ferromagnetic to a ferromagnetic interaction.