Mono and trivalent thallium–sulfur interactions and their influence on the formation of nano thallium sulphide: single crystal X-ray structural and spectral studies on thallium( i )/( iii )–cyclohexylpiperazine dithiocarbamates

Thallium( i ) and thallium( iii )–cyclohexylpiperazine dithiocarbamates have been prepared with the same donor environment for the first time and analyzed by electronic, IR, 1 H, 13 C NMR spectral, CV and single crystal X-ray structural analyses. Solvothermal decomposition of the dithiocarbamates yielded nano Tl 4 S 3 and were characterized. Bond parameters from single crystal X-ray structures have been used in continuous symmetry measure and bond valence sum analysis of the compounds to establish the octahedral geometry and formal oxidation numbers of thallium. [Tl(chpzdtc)] 2 ( 1 ) shows extensive non covalent interactions and the hemidirected TlS 2 CSTl core is of distorted square pyramidal geometry with the stereo chemically active lone pair of thallium( i ) occupying a vertex of the square pyramid. This is the first report which identifies the 4f 7/2 and 4f 5/2 electron binding energies of Tl( i ) and Tl( iii ) dithiocarbamates unambiguously and the effect of Tl⋯C interaction on XPS binding energies. [Tl(chpzdtc) 3 ] ( 2 ), the trivalent analogue as a contrast is a typical holodirected TlS 6 distorted octahedral core with no significant supramolecular interactions. Mean Tl–S bond distances in 1 and 2 are 2.985(7) and 2.6789(19) Å, respectively, which clearly support the higher ease of solvothermal decomposition of 1 to nano Tl 4 S 3 than 2 . A strong correlation exists between the bond strengths of Tl–S, the thioureide C–N and the ease of formation of Tl 4 S 3 from the two dithiocarbamates 1 and 2 .