Molecular structure, X-ray crystallography, spectroscopic characterization, solvent effect, NLO, NBO, FMO analysis of [Cu(bpabza)] complexe

Abstract

In this work, first, the new asymmetric carboxamide ligand of (H2bpabza) was synthesized in the laboratory and it was used to make [Cu(bpabza)] complex. Then, FT IR and NMR spectra and X-ray crystallography were used to examine the structure of tetradentate ligand N,N′-bis (2-pyridinecarboxamide)-2-aminobenzylamine (H2bpabza) and Cu(II) complex. Next, the structure of ligand and the resulting complex were drawn using Chembio Draw Ultra software and powerful Gaussian 09 software, computational methods of Density Functional Theory (DFT), B3LYP and MPW1PW91 methods with LanL2DZ basis set were used to study the structure of ligand and Cu(II) complex, to optimize them and to examine the bond length and the bond angle and these values were compared with experimental values.Then, polarizability of its atoms was calculated using Mulliken charge and natural atomic charges. Stretching and bending vibrations were calculated by FT IR and were compared with experimental values. Also, the chemical shift of carbons and hydrogens were calculated using Nuclear Magnetic Resonance (NMR). Donor-acceptor interactions and Hyperpolarizability calculations were used to determine the type of electron transfers and the amount of global hardness (η) and global softness (S) of molecule were calculated using the energy difference between the highest occupied molecular orbital (HOMO) to the Lowest unoccupied molecular orbital (LUMO) in the presence of solvents CH3OH, DMSO, C6H6 and CHCl3. Also UV–Vis spectra were calculated in the presence of solvents CH3OH, DMSO, C6H6 and CHCl3. DFT/B3LYP and MPW1PW91 methods with LanL2DZ basis set were used in all computational methods.