Synthesis and spectroscopic and thermogravimetric characterization of heterobimetallic complexes with Sn( IV) and Pd( II); DNA binding, alkaline phosphatase inhibition and biological activity studies

A palladium complex, [KLCSS](2)Pd (1), has been prepared by stirring sarcosine (HLH), KOH and CS2 in methanol and subsequently treating with palladium(II) chloride. Six heterobimetallic derivatives of the type [R-2(Cl)SnLCS2](2)Pd (R=Me: 2; Bu: 3; Ph: 4)/[R3SnLCS2](2)Pd (R=Me: 5; Bu: 6; Ph: 7) were also synthesized by stirring sarcosine (HLH) with KOH and CS2 in methanol followed by an addition of R2SnCl2/R3SnCl and then PdCl2. FT-IR data demonstrated bidentate binding of dithiocarbamate and carboxylate with four- and five-coordinate environments around Pd(II) and Sn(IV) centers, respectively, in the solid state. UV-visible studies verified the square planar arrangement around Pd(II) in solution. The magnitude of (2)J(Sn-119-H-1) demonstrates a distorted trigonal bipyramidal geometry around tin(IV) in solution. Elemental analysis (C, H, N, and S), mass spectroscopic (EI-MS and ESI), and thermogravimetric analyses verified the chemical composition of products. Complexes 1-7 exhibited interaction with salmon sperm DNA (SS-DNA). The palladium complex 1 had shown higher potential to bind with SS-DNA and to inhibit the alkaline phosphatase when compared to the heteronuclear products (2-7). However, the antifungal/antibacterial activities of the bimetallic complexes (2-7) were significantly higher than the palladated derivative 1. The in vitro hemolytic activity investigations on human red blood cells showed that bimetallic derivative 2 with chlorodimethyltin(IV) exhibited the lowest hemolytic effects (17.55%), while 5 having trimethyltin(IV) center exhibited the highest hemolytic activity (78.64%).