Syntheses, Structures and Spectral Properties of Mononuclear Cu^II and Dimeric Zn^II Complexes Based on an Asymmetric Salamo‐type N₂O₂ Ligand

Abstract

Abstract The asymmetric Salamo‐type N 2 O 2 ligand H 2 L and its corresponding Cu II and Zn II complexes [CuL] and [{ZnL} 2 ]·2CH 3 CN were synthesized and structurally characterized. Crystallographic data of the Cu II complex revealed that the Cu II ion is tetracoordinate with a slightly distorted square planar arrangement forming a 2D supramolecular plane structure by hydrogen bonding and π···π stacking interactions. In the Zn II complex, the Zn II ions are pentacoordinate in N 2 O 2 tetradentate fashion and intermolecular contacts between Zn II and oxygen atoms result in a head‐to‐tail dimer. The Zn II ions were found to have slightly distorted square pyramidal and trigonal bipyramidal arrangements, respectively. Hydrogen bonding interactions stabilized the Zn II complex to facilitate self‐assembly to a 1D linear chain. The Cu II and Zn II complexes show intense photoluminescence with maximum emissions at approx. 426 and 411 nm upon excitation at 360 and 350 nm, respectively.