Synthesis, Characterization, and Structural Assessment of Ni(II) Complexes Derived from Bis(2-hydroxy-1-naphthaldehyde)succinoyldihydrazone

The monometallic nickel(II) complexes [Ni(H2nsh)(A)2]·nH2O (where A = water (H2O), n=0 (1); pyridine (py), n=2 (2); 2-picoline(2-pic), n=0 (3); 3-picoline(3-pic), n=2 (4); and 4-picoline(4-pic), n=0 (5)) and homobimetallic nickel(II) complexes [Ni2(nsh)(A)4]·nH2O (where A = water (H2O), n=1 (6); pyridine (py), n=4 (7); 2-picoline(2-pic), n=4 (8); 3-picoline(3-pic), n=4 (9); and 4-picoline(4-pic), n=4 (10), resp.) have been synthesized in methanol from bis(2-hydroxy-1-naphthaldehyde)succinoyldihydrazone (H4nsh). The complexes have been characterized by elemental analyses, molar conductance, magnetic moment, and electronic and IR and TGA/DTA spectroscopic studies. The monometallic complexes (1) to (5) are found to have octahedral stereochemistry while complexes (6) to (10) are found to have distorted octahedral stereochemistry in which one of the Ni(II) centres is present in N2O2 coordination sphere and another Ni(II) centre is bonded to it through phenolate oxygen atoms via oxo-bridging