One-dimensional chain constructed via H-bonding and π-π stacking interactions based on the building block of NiL₂·0.5Me ₂CO (HL=N-(8-quinolyl)salicylaldimine): Synthesis, crystal structure, magnetic property and DFT calculation

A compound, NiL₂·0.5Me₂CO (1), was synthesized and structurally characterized. In crystal of 1, the solvent molecule of Me₂CO lies on a 2-fold axis, and the Ni(II) ion was coordinated by two tridente ligands and the core of NiN₄O₂ shows a distortedly octahedral coordination geometry. Two molecules of NiL₂ form a π-dimer and which further connect with each other via H-bonding interaction. The H-bonding interactions between adjacent π-dimers link them into 1D chain. The investigation of magnetic susceptibility measurements indicated that the magnetic coupling interaction within a π-dimer is very weak and the zero-field-splitting dominates the magnetic behavior. DFT calculation revealed that the unpaired electrons in NiL₂ mostly localizes on Ni(II) ion and does not delocalize to the ligands, which lead the two molecules within a π-dimer to possess weak magnetic coupling interaction via π⋯π stacking interaction of ligands that consists with the analysis of the magnetic properties.