Synthesis, spectroscopic, and biological studies of chromium(III), Manganese(II), Iron(III), Cobalt(II), Nickel(II), Copper(II), Ruthenium(III), and Zirconyl(II) Complexes of N1,N2-Bis(3-((3- hydroxynaphthal en-2-yl)methylene-amino)propyl) phthalamide

Abstract

Novel chromium(III), manganese(II), iron(III), cobalt(II), nickel(II), copper(II), ruthenium(III), and zirconyl(II) complexes of N1,N 2-bis(3-((3-hydroxynaphthal en-2-yl)methylene-amino)propyl) phthalamide (H4L, 1) have been synthesized and characterized by elemental, physical, and spectral analyses. The spectral data showed that the ligand behaves as either neutral tridentate ligand as in complexes 2-5 with the general formula [H4LMX2(H2O)]·nH 2O (M=Cu(II), Ni(II), Co(II), X = Cl or NO3), neutral hexadentate ligand as in complexes 10-12 with the general formula [H 4LM2Cl6]·nH2O (M=Fe(III), Cr(III) or Ru(III)), or dibasic hexadentate ligand as in complexes 6-9 with the general formula [H2LM2Cl2(H2O) 4]·nH2O (M = Cu(II), Ni(II), Co(II) or Mn(II), and 13 with general formula [H4L(ZrO)2Cl2] ·8H2O. Molar conductance in DMF solution indicated the non-ionic nature of the complexes. The ESR spectra of solid copper(II) complexes 2, 5, and 6 showed g∥>g>ge, indicating distorted octahedral structure and the presence of the unpaired electron in the dx2-y2 orbital with significant covalent bond character. For the dimeric copper(II) complex [H2LCu2Cl 2(H2O)4]·3H2O (6), the distance between the two copper centers was calculated using field zero splitting parameter for the parallel component that was estimated from the ESR spectrum. The antibacterial and antifungal activities of the compounds showed that, some of metal complexes exhibited a greater inhibitory effect than standard drug as tetracycline (bacteria) and Amphotricene B (fungi).