Salicylaldimine‐bridged dinuclear cyclopalladated complexes: Synthesis, characterization and BSA binding studies

Abstract

Salicylaldimine‐bridged dinuclear cyclopalladated complexes were synthesized by the reactions of cyclopalladated chloro dimers [Pd{(4‐R)C6H3CH=N‐C6H3–2,6‐i‐Pr2}(μ‐Cl)]2 (R = H; OMe) with salen‐based bridging ligands. The complexes were characterized by FTIR, NMR spectroscopy, elemental analysis and X‐ray crystallography. The binding interaction of cyclopalladated complexes to bovine serum albumin (BSA) was investigated by UV–vis, fluorescence and synchronous fluorescence spectroscopy. The experimental results showed that these Pd (II) complexes could bind to BSA with high affinity and quench its intrinsic fluorescence by a static or combined process. Also the interaction of Pd complexes with BSA affected the conformation of the tryptophan and tyrosine residues.