Supramolecularly linked linear polymers of thallium(I) dithiocarbamates: Steric influence on the supramolecular interactions of methyl and ethylcyclohexyl dithiocarbamates of thallium(I)

Spectral and single crystal X-ray structural studies on [Tl(mchdtc)](2) (1) and [Tl(echdtc)](2) (2) (where mchdtc = methylcyclohexyldithiocarbamate and echdtc = ethylcyclohexyldithiocarbamate) were carried out. Both the synthesized complexes were characterized by UV-Vis, fluorescence, IR, H-1 and C-13 NMR spectra. IR spectra of the complexes show the contribution of the thioureide form to the structures. Both compounds show weak fluorescence. The bond valence sums calculated for the complexes support the highly covalent nature of the Tl-S interactions. A Tl center dot center dot center dot center dot H short interaction observed in the methyl analogue is totally absent in (2) because of the change in conformation of the cyclohexyl ring due to the introduction of ethyl group. Though the neighbouring non-bonded groups are flexible, thallium adjusts its thallophilic contacts to retain a hemisphere free for its pair of 's' electrons in the presence of a sterically demanding ethyl group.