Anagostic, mono- and hexahapta interactions in Tl(I) dithiocarbamates: A new precursor for the preparation of Tl2S nanoparticles

Two new homoleptic complexes, [Tl(bzfdtc)](2) (1) and [Tl(bu(2-OH)bzdtc)](2) (2) (where bzfdtc = N-benzyl-N-furfuryldithiocarbamate and bu(2-OH)bzdtc = (N-butyl-N-(2-hydroxybenzyl)dithiocarbamate), have been prepared and characterized by IR, NMR (H-1 and C-13), UV-Vis spectroscopy, cyclic voltammetry and single crystal X-ray structural analysis. X-ray crystallography revealed that both complexes are dimers. Both complexes show two monohapta Tl center dot center dot center dot C(S-2) interactions. The Tl center dot center dot center dot Tl distances are 3.635 and 3.719 angstrom for 1 and 2, respectively. The phenyl ring of the bzfdtc ligand is coordinated (by a eta(6) interaction) to the Tl+ ion in complex I. A rare intramolecular anagostic C-H center dot center dot center dot Tl interaction is observed in complex 2. Thallium sulfide nanoparticle samples 3 and 4 have been prepared from complex I using conventional heating and microwave irradiation, respectively. Samples 3 and 4 have been characterized by PXRD, EDAX, HR-TEM, UV-Vis absorption and fluorescence spectroscopy. PXRD measurements revealed rhombohedral and hexagonal phases for samples 3 and 4, respectively. EDAX confirmed the formation of Tl2S. HR-TEM images showed that the size and morphology of the Tl2S nanoparticles are affected by the method of preparation (conventional heating compared to microwave irradiation). (C) 2015 Elsevier Ltd. All rights reserved.