Crystal structure and spectral characterization of dimethylthallium(III) complexes with 2-mercaptonicotinic acid and esters

Synthesis, spectral properties and crystal structure of dimethylthallium( III) complexes with 2-mercaptonicotinic acid (2mna), 2-mercapto-methyl-nicotinate (2mmn), 2-mercapto-ethyl-nicotinate (2men) and 2-mercapto-isopropyl-nicotinate (2min) are reported. The compounds were characterized using IR, multinuclear NMR (H-1, C-13, Tl-205) and mass spectrometry (electrospray, ES-API). The molecular structures of [TlMe2(2mna)] . H2O, (1), [TlMe2(2mmn)], (2), [TlMe2(2men)], (3) and [TlMe2(2min)], ( 4) were determined by the single-crystal X-ray diffraction. In 1, the monodeprotonated O,S-bidentate ligand chelates one dimethylthallium( III) unit and simultaneously bridges (O and S) between two of these organometallic units. The Tl-O1' and Tl-S" interactions are leading to polymeric chain linked in a three-dimensional network by the hydrogen bonds formed between the water molecule and the oxygen O(2) atom of the acid. The thallium atom is in a distorted octahedral environment with a [ TlC2O2S2] kernel. Compounds 2, 3, and 4 are similar, in all the cases already mentioned the ligand is NH deprotonated and is strongly coordinated to two dimethylthallium( III) units through the N and S atoms. Two additional weak interactions with the O and S atoms lead to a [TlC2NOS2] kernel for the metal atom, in which the coordination polyhedron is a very distorted octahedron with the methyl groups occupying the apical positions. (C) Central European Science Journals. All rights reserved.