Theoretical studies, Hirshfeld surface analysis, and crystal structure determination of a newly synthesized benzothiazole copper(II) complex

Abstract

A mononuclear copper(II) complex [Cu(LBTZ)2] was synthesized from the Schiff base HLBTZ (2-(benzo[d]thiazol-2-yl)-6-ethoxyphenol). The structural validation of the compounds was carried out with the help of different studies viz., elemental (C, H, and N), FT-IR, NMR (1H and 13C), and for [Cu(LBTZ)2], by X-ray crystal diffraction method. The complex was crystallized out in the orthorhombic Pbcn space group and exhibits a highly distorted tetrahedral geometry. Hirshfeld surface (HS) analysis using 2D fingerprint plots of the [Cu(LBTZ)2] was conducted to elaborate on different kinds of non-covalent, inter, and intramolecular interactions that existed in the solid crystalline scaffolds, which accounted for the strengthening of the crystal lattice. The molecular structures of the HLBTZ and [Cu(LBTZ)2] were further investigated by optimizing them with the help of DFT using the B3LYP hybrid method, and the Def2-TZVP basis set. The optimized geometries of the compounds and their related molecular parameters like frontier orbital energy gap, dipole moment, molecular electrostatic potential map, and natural bond orbitals calculation have also been used to understand the properties.