Copper(II) Monomer Bearing Phenolate-Based Ligand: Theoretical and Experimental Visions

Abstract

Using protonated forms of tridentate phenol amine ligand 2-((benzyl(pyridine-2-ylmethyl)amino)methyl)phenol (HL) mononuclear copper(II) complex was synthesized. This ligand yielded mononuclear complex of composition [Cu(HL)Cl₂] (1) which has been characterized by X-ray crystallography, UV–vis, and EPR measurements. Complex 1 shows axial spectra typical of d⁹ (d_x2-y2 as ground state) configuration. Using DFT/B3LYP/LANL2DZ and 6-311++G(d,p) level of theory, structural optimization, electronic and vibrational characteristics of the ligand and complex were examined. The experimental and theoretical parameters are quite well aligned. The assignments of the vibrational frequencies were performed by potential energy distribution analysis by using VEDA program. Molecular electrostatic potential and frontier molecular orbitals analysis have been carried out to understand the molecule reactivity. A TD-DFT computation is also started to replicate the UV–vis absorption spectrum and to determine various essential electronic parameters such as the HOMO–LUMO gap energy and electronic transitions.

Keywords:

• Mononuclear copper complex
• EPR
• optimization
• vibrational analysis
• TDDFT
• MEP

Acknowledgements

The authors thank Prof. R.N. Mukherjee for using the lab facilities at IIT Kanpur and acknowledge Dr. Bhimrao Ambedkar University, Agra for infrastructure and facilities.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors also extend their appreciation to Taif University Researchers Supporting Project number (TURSP-2020/241), Taif University, Taif, Saudi Arabia.