Synthesis, spectroscopic, and cytotoxicity studies of some diamine and diimine platinum(II) complexes of diethyldithiocarbamate

Four new water soluble complexes of the formula [Pt(DA)(DDTC)]NO₃ (where DA is 2,2'-bipyridine, 1,10-phenanthroline, 1,2-diaminopropane, or 1,2-diaminocyclohexane, and DDTC is diethyldithiocarbamate anion) have been synthesized by reaction of platinum-diamine/diimine diaqua complex with sodium diethyldithiocarbamate in molar ratio of 1:1. These complexes have been characterized by the chemical analysis, and ultraviolet-visible, infra-red and ¹H NMR spectroscopy. The infrared and ¹H NMR spectral studies of these complexes have ascertained the modes of binding of diamine/diimine and diethyldithiocarbamate to platinum. The molar conductance values of these platinum complexes in conductivity water suggest them to be 1:1 electrolytes. These four complexes and two other complexes containing ethylenediamine and 1,3-diaminopropane ligands have been tested against P-388 lymphocytic leukemic cells. Out of them only 2,2'-bipyridine and 1,10-phenanthroline complexes show I.D.₅₀ values less than cisplatin.