Synthesis, spectroscopic and magnetic studies of cobalt(II), nickel(II) and copper(II) complexes with 3'- and 5'-methoxysalicylaldimine-3-ethylene-1H-indole. X-ray structure of bis(1H-indole-3-ethylene-5'-methoxysalicylaldimine) copper(II)

Abstract Two bidentate ligands and their cobalt(II), nickel(II) and copper(II) complexes are reported; these ligands were prepared by 1:1 Schiff base condensation of 3-(2-aminoethyl)indole (tryptamine, TPA) with salicylaldehyde derivatives. The structures of the compounds were assigned on the basis of IR, electronic, mass and tH NMR data. Bis(1H-indole-3-ethylene-5′-methoxysalicyIaldimine)copper(II), (C36H34N4O4Cu), crystallized in monoclinic space group P21/c and was subjected to a single-crystal X-ray structure analysis. The structure was solved by direct and Fourier methods, refined by full-matrix least-squares, and converged to a R value of 0.038 for 1358 observed reflections. The coordination of the copper(II) complex is trans-planar (CuO2N2) with Cu-O and Cu-N bond lengths of 1.88(1) A and 2.01(1) A, respectively. The magnetic susceptibilities of the two copper complexes show normal magnetic behaviour in the range 79–279 K. The coordination of the two nickel complexes is trans-planar (NiO2N2) and bo...