DFT Calculations, Spectroscopic Studies, Biological Activity and Non Linear Optical Properties (NLO) of Novel Ternary Cu(II)-Chelates Derived from 5-Acetyl-4-hydroxy-2H-1,3-thiazinedione

Abstract

New ternary Cu(II)-chelates with the general formula [ML L′(H2O)x] (NO3)y x (H2O), x = 0–2 and y = 0–1, (L) = 5-acetyl-4-hydroxy-2H-1,3-thiazine-2,6(3H)-dione with in the presence of a secondary ligand (L′) [N,O-donor; 8 hydroxyquinoline or N,N-donor; 1,10-phenanthroline and diethethylendiamine]. Characterization of the synthesized complexes was established based on elemental analysis, molar conductance, magnetic susceptibility measurements, spectral (infrared, electronic, mass, 1H-NMR and ESR) as well as thermal gravimetric analysis (TGA). The complexes exhibited octahedral and square planer geometry. The antimicrobial activity for the studied complexes was tested for different kind of organisms. The geometrical and non-linear optical parameters of the studied complexes 1–3 are investigated theoretically at the B3LYP/GENECP level of theory. The optimized geometries of the studied complexes are non-planner as indicated from the dihedral angles. The natural charge population (core, valence and Rydberg), exact electronic configuration, total Lewis, and total non-Lewis is computed and discussed in terms of natural bond orbitals (NBO) analysis. The calculated EHOMO and ELUMO energies at the same level of theory of the studied complexes were used to calculate the global properties; hardness (η), global softness (S), electrophilicity (ω) and electronegativity (χ). The total dipole moment (μtot), total and anisotropy of polarizability (˂α˃), (Δα) and first hyperpolarizability (˂β˃) values were calculated and compared with urea as a reference compound. From the values of the computed first hyperpolarizability (˂β˃), the ligand and the studied complexes show promising optical properties.