Synthesis, characterization, NLO properties, antimicrobial, CT-DNA binding and DFT modeling of Ni(II), Pd(II), Pt(II), Mo(IV) and Ru(I) complexes with NOS Schiff base

Abstract

Thermal reaction of Ni(NO3)2.6H2O, PdCl2, PtCl2, Mo(CO)6 and Ru3(CO)12 with the prepared Schiff base ligand N-(2-hydroxy-1-naphthylidene)-2-aminothiophenol (H2L) resulted in the formation of the five complexes; [Ni(HL)2], 1; [Pt(H2L)Cl2], 2; [Pd2(HL)2Cl2], 3; [Mo(O2)(H2L)], 4; and [Ru(CO)3(HL)], 5. The studied compounds were characterized using different spectroscopic techniques (IR, 1H NMR, mass) elemental analyses, magnetic measurement, molar conductance, and thermal analysis. The kinetic and thermodynamic parameters of the complexes were computed. The geometry of studied 1:1 Pt(II)-, Pd(II)- Mo(IV)- and Ru(I)- complexes and 1:2 Ni(II)- complex were investigated at the B3LYP/GENECP level of theory. The geometries of the studied complexes are non-planner as indicated from the dihedral angles between central metal ion and coordinated atoms of the ligand. DFT calculations have been also carried out to calculate the global properties; hardness (η), global softness (S) and electronegativity (χ). The mean first-order hyperpolarizability (<β>) was calculated and compared with Urea as a reference material. The results of the mean first-order hyperpolarizability (<β>) showed that the ligand and the studied complexes are excellent candidates to NLO materials. Also, the interaction of the reported compounds with calf thymus DNA (CT-DNA) by different techniques revealed that the complexes could bind to CT-DNA by intercalative mode. The binding of the reported complexes to calf thymus DNA has been investigated using fluorescence and UV–Vis absorption spectra. The results indicated a much lower binding affinity of the ligand than that of the complexes. Biological activities of the compounds have been studied.