Crystal structure of 3-acetylcoumarin-o-aminobenzoylhydrazone and synthesis, spectral and thermal studies of its transition metal complexes

Transition metal [Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II)] complexes of a new Schiff base, 3-acetylcoumarin-o-aminobenzoylhydrazone were synthesized and characterized by elemental analyses, magnetic moments, conductivity measurements, spectral [Electronic, IR, 1H and 13C NMR, EPR] and thermal studies. The ligand crystallizes in the monoclinic system, space group P21/n with a = 9.201(5), b = 16.596(9), c = 11.517(6) Å,  = 101.388(9)°, V = 1724.2 (17) Å3 and Z = 4. Conductivity measurements indicated Mn(II) and Co(II) complexes to be 1 : 1 electrolytes whereas Ni(II), Cu(II), Zn(II) and Cd(II) complexes are non-electrolytes. Electronic spectra reveal that all the complexes possess four-coordinate geometry around the metal.