Tetranuclear Cu(II) complex with [2+4] Cu4O4 cubane based core framework derived from 2-[{2-(1-hydroxy-ethyl)-phenylimino}-methyl]-6-methoxy-phenol: Quantifying conventional and unconventional interactions and QTAIM analysis

Abstract

A cubane based tetranuclear copper(II) complex prepared using 2-[{2-(1-hydroxy-ethyl)-phenylimino}-methyl]-6-methoxy-phenol and copper(II) acetate has been characterized by spectral techniques and single-crystal X-ray diffraction studies. The complex crystallizes in the space group P21/c has elongated (4+1) distorted square pyramidal geometry. The Cu(II) ions connected by chiral alcoholic oxygen atom leads to the formation of [2+4] cubane based core framework (Cu4O4). The results obtained in the DFT using the ADF at GGA/PW91/TZP level were compared with the experimental results. The complex exhibits intramolecular H–O···π, C-N···H, and C-O···H interactions in the solid-state. DFT calculations analyzed the conventional C-O···H, C-H···H, C-H···π (arene), and unconventional C-H···π (chelate) non-covalent interactions in the crystal packing. A complete analysis of NCI plots (non-covalent interaction) and Hirshfeld surfaces and 2D fingerprint plots have quantified the interactions. Beside, the interactions have been exemplified by QTAIM analysis.