PYRIDOXAL THIOSEMICARBAZONATE MONOHYDRATE OF DIMETHYLTHALLIUM(III) - X-RAY STRUCTURE AND SPECTROSCOPIC PROPERTIES

摘要

The title compound, [TIMe2(HL) (H2O)] (HL = monoanion of pyridoxal thiosemicarbazone), crystallizes in the triclinic space group P (1) over bar (C-i(1), No. 2). The HL- anion coordinates to the thallium atom, in an unusual mode through the S atom (Tl-S = 2.832(1) Angstrom), and also forms a weak bond with the metal atom of a neighbouring molecule to make an asymmetric bridge (Tl'... S = 3.190(1) Angstrom. The acidic proton retained in the thiosemicarbazonato anion is located on the oxygen of the phenolic hydroxyl group. The water molecule is only 2.630(4) Angstrom from the metal, suggesting a rather strong bond that contrasts with the long distance between the thallium and the phenolic oxygen (Tl ... O(1)'=3.124(4) Angstrom). If both strong and weak intermolecular interactions are taken in account, the metal has distorted octahedral coordination with the methyl groups in apical positions. The solid state IR spectrum and H-1, C-13 and Tl-205 NMR spectra in DMSO solution are also discussed. [References: 31]