CT-DNA/BSA protein binding and antioxidant studies of new binuclear Pd(II) complexes and their structural characterisation

•Four new binuclear palladium(II) complexes have been synthesized and characterised.•The DNA and protein interactions of these complexes were studied by a spectroscopically.•Significant antioxidant activity was found for the new complexes.

New palladium(II) binuclear complexes (1–4) of the type [Pd2(Msal-Rtsc)2(μ-dppm)] (R = H or CH3 or C2H5 or C6H5) were prepared and characterised by using various spectro analytical techniques. The true coordinating nature of the ligands in the complexes was confirmed by X-ray crystallographic studies. From the X-ray crystallographic analysis, it is found that the ligands [H2L1–H2L4] were bound to metal as tridentate ONS donors and phosphorus atom of bridged diphenylphosphinomethane satisfied the fourth coordination site in both the metal units to form a binuclear complexes. The interaction mode of the complexes (1–4) with calf-thymus DNA (CT-DNA) has been explored by absorption titrations and ethidium bromide displacement study was used to confirm the mode of binding. Based on the results obtained, electrostatic and intercalative binding modes have been proposed. Quenching the tryptophan and tyrosine residues of Bovine Serum Albumin (BSA) by complexes were found as static. Anti-oxidant properties of the complexes were tested against, 2,2′-diphenyl-1-picrylhydrazyl radical (DPPH), superoxide anion radicals.

Graphical abstractNew Pd(II) complexes were synthesized by reacting K2[PdCl4] with Schiff base ligands and 1,1′-bis-diphenylphosphinomethane in 2:2:1 M ratio. The new complexes obtained were structurally characterised by X-ray crystallography. Significant DNA/BSA protein binding and radical scavenging ability were found for the complexes.Figure optionsDownload full-size imageDownload as PowerPoint slide