Synthesis, spectral, structural and DFT studies on Tl(III) dithiocarbamate complexes: Preparation of Tl2S nanoparticles from tris(N-benzyl-N-furfuryldithiocarbamato-S,S’)thallium(III)

Abstract

Tris(N,N-difurfuryldithiocarbamato-S,S’)thallium(III) (1), tris(N-benzyl-N-furfuryldithiocarbamato-S,S’)thallium(III) (2) and tris(N-furfuryl-N-(2-phenylethyl)dithiocarbamato-S,S’)thallium(III) (3) have been prepared and characterized by elemental analysis, IR and NMR (1H and 13C) spectroscopy. Single crystal X-ray structural analysis was carried out for 1. X-ray crystallography revealed that complex 1 is monomer. Thallium is hexacoordinated with six sulfur atoms from three chelating N,N-difurfuryl dithiocarbamate ligands in a distorted octahedral geometry. Complex 1 is further stabilized by various interactions such as CH…π (chelate), CH…π, CH…S and CH…O interactions. CH…O interactions lead to the formation of 18 membered macrocyclic ring. Hirshfeld surface analysis (dnorm surface and 2-D fingerprint plots) were performed using Crystal explorer 3.1 program. The major contributions for the crystal packing are from H…H, S…H/H…S, O…H/H…O and C…H/H…C interactions. Molecular optimization, molecular electrostatic potential and frontier molecular orbitals were calculated using DFT method for 1. DFT calculations on 1 revealed that HOMO was localized predominantly over furfuryl ring carbon atoms, whilst the LUMO was located on Tl and S atoms, with the HOMO-LUMO energy gap being 2.5067 eV. Thallium sulfide nanoparticles Tl2S-1 and Tl2S-2 have been prepared from complex 2 using conventional heating and microwave irradiation, respectively. The as-prepared Tl2S nanoparticles have been characterized by PXRD, EDS, HR-TEM, UV–vis absorption and fluorescence spectroscopy. The X-ray diffraction pattern confirms the rhombohedral phase of as-prepared Tl2S.

Keywords

• Thallium dithiocarbamate
• DFT studies
• Single source precursors
• Thallium sulphide
• Nanoparticles