Synthesis, Characterization and Biological Activity of Organotin(IV) Complexes featuring di-2-ethylhexyldithiocarbamate and N-methylbutyldithiocarbamate as Ligands

Abstract

Organotin(IV) compounds have received tremendous attention for their synthesis, characterization and biological activities and their ability to bind with sulfur ligand such as dithiocarbamate ligand. Organotin(IV) dithiocarbamate complexes can be synthesized by the reaction of carbon disulphide with secondary amine. Four new organotin(IV) dithiocarbamate complexes were successfully synthesized by the reactions between di-2-ethylhexyldithiocarbamate, C16H34NCS2 and N-methylbutyldithiocarbamate, C5H12NCS2 with dibutyltin(IV) dichloride and triphenyltin(IV) chloride, RxSnClx (R = Bu, Ph) and (x = 1, 2 or 3). These series of complexes were synthesized using “in situ” insertion method and characterized by determination of melting point, CHNS elemental analysis, infrared spectroscopy (FT-IR) and UV-vis spectroscopy. The melting points of the synthesized compounds were in the range 88.3 - 128.4 °C. The experimental CHNS data of the compounds, mostly exhibit the calculated CHNS values. Using infrared spectra (FT-IR), the formation of organotin(IV) dithiocarbamate complexes were confirmed by the presence of v(C=N+) at 1464 - 1497 cm-1, v(C-S) at 963 - 1025 cm-1 and v(Sn-S) at 412 - 445 cm-1 in all complexes. Besides that, the UV-vis analysis showed the peaks chromophore of N=C within range 259 - 260 nm, nonbonding electron on sulphur and charges transferred between the tin metal and ligand (M-L). Using TGA analysis, complex 1 and 3 show two degradation curve but complex 2 and 4 shows only one degradation curves. The antibacterial activity of all synthesized organotin(IV) dithiocarbamate complexes were then determined towards four types of bacterial strains which were Escherichia coli, Staphylococcus aureus, Salmonella thypi and Bacillus cereus. Penicillin was used as positive control and streptomycin as negative control in order to compare diameter of inhibition zone between both controls and complexes. From antibacterial test, almost all synthesized complexes were found to give positive results. Thus, it can be concluded that the complexes formed do have applications in biological and medical aspects.