Amine-bridged binuclear complexes involving [Pd(ethylenediamine)(H 2 O) 2 ] , 4,4′-bipiperidine and DNA constituents.

The complex formation equilibria in the reaction of [Pd(en)(H2O)2]2+with 4,4′-bipiperidine (Bip) and DNA constituents such as inosine, inosine-5′-monophosphate, uracil, uridine, thymine, and thymidine were investigated at 25 °C and 0.1 M ionic strength. The [(H2O)(en)Pd(Bip)Pd(en)(H2O)]4+complex and its hydrolyzed species were formed. Substitution of coordinated water by inosine (Ino) as DNA constituent formed the complexes [(Ino)(en)Pd(Bip)Pd(en)(H2O)]3+and [(Ino)(en)Pd(Bip)Pd(en)(Ino)]2+. The formation of the binuclear complexes was further supported by spectral measurements. The formation constants of all possible mono- and binuclear complexes were determined and their speciation diagrams were evaluated. Binuclear complexes involving 4,4′-bipiperidine linkage of two Pd(en)2+species were investigated. The binding of DNA constituents to the binuclear complex was studied. [ABSTRACT FROM AUTHOR]