New homobimetallic organotin(IV) dithiocarbamates as potent antileishmanial agents

In the present study, di-and triorganotin(IV) dithiocarbamates, (n-Bu₂SnCl) ₂L (1), (Ph₂SnCl) ₂L (2), (Ph₃Sn ₂L (3), and (Bz₃Sn₂L (4), have been synthesized, where L is 4,4-trimethylenedipiperidine-1-carbodithioate. The coordination mode of the ligand to Sn, structural confirmation and geometry assignment around Sn(IV), in solid and solution forms, were made using FT-IR, multinuclear NMR (¹H and ¹³C), and X-ray single crystal analysis. The latter technique confirms anisobidentate mode of chelation of the ligand with Sn, in 1-4, with distorted trigonal bipyramidal or square pyramidal geometry. Complexes 1-4 present supramolecular structures mediated by different CH and ClH intermolecular interactions. These complexes maintain five-coordination even in solution, except for 4. The antileishmanial activity of all complexes are well above the standard drug, especially (Bz₃Sn ₂L. The Docking studies suggest that high antileishmanial action of (Bz₃Sn ₂L is due to its lowest binding energy with enzyme trypanothione synthetase. The antileishmanial activity of the complexes is promising enough that they may be used for antileishmanial treatment after further investigations.