Deciphering the bonding mode of the trihalide ligands in a series of halogen carrier homo- and hetero-trihalide Cu(II) Schiff base complexes

The molecular and electronic structure of the [Cu(RdienR)(X)(XY2)] complexes and their [Cu(RdienR)(X)2] precursors were analyzed in terms of charge decomposition analysis (CDA), natural bond orbital (NBO) population analysis, and percentage compositions of molecular orbitals in order to understand the nature of the bonding between the [XY2]− ligands and the Cu(II) central metal ion, and unveil the effect of coordination on the bonding mechanism in the coordinated [XY2]− ligands in comparison to that of the “free” [XY2]− anions.