Rare coordination behavior of triethanolamine ligand in [Cu(H3tea)2](3,4-dimethoxycinnamate)2·2H2O: Synthesis, characterization, single crystal X-ray structure determination, Hirshfeld calculation and molecular docking studies

Abstract

Herein, unusual and rare coordination behavior of triethanolamine (H3tea) ligand in copper(II) carboxylate complex; [Cu(H3tea)2](3,4-DMC)2·2H2O; DMC = 3,4-dimethoxycinnamate, has been explored and structurally reported for the first time. Synthesis and crystallization of the complex has been achieved at ambient conditions using methanol-water (4:1 v/v) as a solvent mixture after very slow evaporation. Furthermore, the complex is characterized by elemental analyses, spectroscopic methods (UV–Visible, FT-IR) and structure elucidation has been carried out by single crystal X-ray structure analyses. X-ray structure determination of the complex revealed the presence of [Cu(H3tea)2]2+ as a cation and two moieties of 3,4-dimethoxycinnamate as anions forming a second sphere coordination complex. Various weak (non-covalent) interactions such as CH∙∙∙O, and OH∙∙∙O impart an important role in the lattice stabilization of a second sphere coordination complex. Hirshfeld surface calculations clearly revealed the existence of interplay of non-covalent interactions in lattice stabilization. The theoretical calculation also suggested the total interaction energies in this complex, i.e. 32.6 kj.mol−1. In addition, molecular docking investigations of this complex clearly showed that there is substantial protein-ligand interaction with best binding scores of -7.2, -7.3, -7.9 kcal/mol against 4GKU, 3W4P, 5CGX and -5.8, -7.8 kcal/mol against 4HFZ, 1D5R proteins lesser than parent acid i.e. 3,4-dimethoxycinnamic acid indicating the potential of this complex; [Cu(H3tea)2](3,4-DMC)2·2H2O as antibacterial and anticancer agent respectively.