Synthesis and spectral studies of bisthiocarbohydrazone and biscarbohydrazone of quinoline-2-carbaldehyde: Crystal structure of bis(quinoline-2-aldehyde) thiocarbohydrazone

摘要

Two new ligands, having flexible coordination ability, 1,5-bis(quinoline-2-carbaldehyde) thiocarbohydrazone and 1,5-bis(quinoline-2-carbaldehyde) carbohydrazone were synthesized and characterized by elemental analysis, IR, and UV spectral studies. The compounds exist in the thione/ketone tautomeric forms, as evidenced by IR spectral data. The structure of bis(quinoline-2-aldehyde) thiocarbohydrazone has been solved by single crystal XRD study. The compound C21H16N6S crystallizes in triclinic form with two independent molecules in the asymmetric unit, space group P (1) over bar, Z = 4, V = 1856.1(6) angstrom(3) with unit cell parameters a = 11.331(2) angstrom, b = 11.714(2) angstrom, c = 15.116(3) angstrom, alpha = 100.369(4)degrees, beta = 109.512(4)degrees and gamma = 90.134(4)degrees. Both molecules exist in the thione forms and show a Z-Z configuration about both azomethine bonds, with quinoline nitrogens on opposite sides. The N-N, N-C and the C-S bond distances of the thiocarbohydrazide moiety suggest extensive electron delocalization of the whole thiocarbohydrazone moiety.