Synthesis, spectroscopic characterization, X-ray structure and evaluation of binding parameters of new triorganotin(IV) dithiocarboxylates with DNA.

Three new triorganotin(IV) dithiocarboxylates (1-3) with general formula R(3)SnL, where R=C(4)H(9) (1), C(6)H(11) (2), C(6)H(5) (3) and L=4-(4-nitrophenyl)piperazine-1-carbodithioate, have been synthesized and characterized by elemental analysis, Raman, FT-IR, multinuclear NMR ((1)H, (13)C and (119)Sn) and mass spectrometry. The crystal structure of complex 3 confirmed distorted trigonal-bipyramidal geometry around Sn atom. The interaction of compounds 1-3 with DNA was investigated by cyclic voltammetry (CV) and UV-vis spectroscopy. The positive peak potential shift in CV and hypochromic effect in spectroscopy evidenced intercalative mode of interaction. The results indicate that the binding affinity varies in this sequence: 1>3>2.