SYNTHESIS, SPECTROSCOPIC AND STRUCTURAL CHARACTERIZATION OF METHYL PYRUVATE-HYDRAZINOPYRUVOYLTHIOSEMICARBAZONE AND PYRIDOXAL-HYDRAZINOPYRUVOYLTHIOSEMICARBAZONE

Two new thiosemicarbazones, methyl pyruvate-hydrazinopyruvoylthiosemicarbazone (H2mpipt), pyridoxal-hydrazinopyruvoylthiosemicarbazone (H2piript), and their common reaction intermdiate, pyruvic acid thiosemicarbazone hydrazide (Hipt), have been synthesized and characterized using IR and NMR spectroscopic methods. The crystal structures of H2mpipt and Hipt.H2O have been determined by X-ray crystallographic methods. Both compounds form monoclinic crystals belonging to the space group P2(1)/c with Z = 4 (a = 11.050(2), b = 10.386(2), c = 11.468(2) angstrom, beta = 114.87(3)-degrees and a = 7.476(1), b = 15.359(3), c = 8.367(1) angstrom, beta = 114.43(3)-degrees, respectively). The ligand H2mpipt reacts with [Cu(PPh3)Cl]4 and forms the Cu(I) complex [Cu(PPh3)2(H2mpipt)Cl].CH3OH whose structure has been determined by X-ray crystallographic methods. The copper atom has a distorted tetrahedral coordination sphere involving a chlorine atom, the phosphorus atoms of the two PPh3 molecules and a sulfur atom of the H2mpipt moiety. The crystals of the complex are triclinic, space group P1BAR, Z = 2, a = 18.331(2), b = 10.025(2), c = 13.697(2) angstrom, alpha = 72.17(2), beta = 97.77(2), gamma = 87.42(2)-degrees. The configuration of H2mpipt in the complex is different from that of the free ligand. The H-1, C-13 and N-15 NMR spectra for H2piript are also discussed.