Coordination of ZnII, CdII, and HgII by 2-Pyridineformamide-3-piperidyl-thiosemicarbazone
作者:Alfonso Castiñeiras、Isabel García、Elena Bermejo、Karen A. Ketcham、Douglas X. West、Ayman K. El-Sawaf
DOI:10.1002/1521-3749(200202)628:2<492::aid-zaac492>3.0.co;2-v
日期:2002.2
Sodium in dry methanol reduces 2-cyanopyridine in the presence of 3-piperidylthiosemicarbazide and produces 2-pyridineformamide-3-piperidylthiosemicarbazone, HAmpip. Complexes with zinc(II), cadmium(II), and mercury(II) have been prepared and characterized by elemental analyses and spectroscopic techniques. In addition, the crystal structures of [Zn(Ampip)(2)], [Zn(Ampip)(Oac)](2), [Cd(HAmpip)Cl-2].(CH3)(2)SO, [Cd(HAmpip)Br-2] (.) (CH3)(2)SO, [Cd(HAmpip)I-2].(CH3)(2)SO, [Cd(Ampip)(2)] and [Hg(HAmpip)Br-2].(CH3)(2)SO have been solved. Coordination of the anionic and neutral thiosemicarbazone ligand is via the pyridyl nitrogen, imine nitrogen and thiolato/thione sulfur atom, respectively. In [Zn(Ampip)(OAc)](2) one of the bridging acetato ligands has monodentate coordination and the other bridges in a bidentate manner. Cd-113 NMR studies were carried out on the [Cd(HAmpip)X-2] (X = Cl, Br or I) and [Cd(Ampip)(OAc)](2) complexes. The Cd-113 chemical shifts are affected by the halogen and range from 411 to 301 ppm, and the spectrum of [Cd(Ampip)(OAc)](2) shows two signals at 450 and 251 ppm. The Hg-199 NMR spectrum of [Hg(HAmpip)Cl-2] also is discussed.