Synthesis and characterization of water-soluble, heteronuclear ruthenium(III)/ferrocene complexes and their interactions with biomolecules

• Multinuclear ruthenium(III)/ferrocene complexes have been synthesized and characterized.
• XAS and EXAFS studies indicate chloride substitution by nitrogen donors from BSA.
• Gel electrophoresis mobility shifts of RuL2 with DNA are similar to cisplatin with DNA at certain concentrations.

The reaction of Na[RuCl4(SO(CH3)2)2], 1, with one equivalent of FcCONHCH2C6H4N (Fc = FeC10H9), L1, FcCOOCH2CH2C3H3N2, L2, FcCOOC6H4N, L3, afforded the dinuclear species, Na[FcCONHCH2C6H4N[RuCl4(SO(CH3)2)]], RuL1, Na[FcCOOCH2CH2C3H3N2[RuCl4(SO(CH3)2)]], RuL2, Na[FcCOOC6H4N(RuCl4(SO(CH3)2))], RuL3, respectively, yielding, in each case, a ferrocene moiety bridged to a ruthenium center. The complexes were characterized by NMR, IR, and XRD (X-ray diffraction). The sulfoxide ligands are bonded to the metal through the sulfur atom. The complexes were evaluated for their biological activity with pBluescript DNA plasmid, and the protein BSA (bovine serum albumin). These reactions were monitored by XAS (X-ray absorption spectroscopy), EXAFS (extended X-ray Absorption Fine Structure), NMR, UV/visible, emission spectroscopy, and gel electrophoresis. Donor atoms from the biomolecules substitute for the chloride ligands in the parent complexes.

A series of ruthenium(III)/ferrocene dinuclear complexes were synthesized and characterized by NMR, IR, and XRD. The substitution reactions with BSA were followed using a variety of spectroscopic (NMR, UV/vis, XAS, EXAFS) techniques indicating that BSA-metal bonding occurs when N-donors from BSA substitute for chloride ligands on the ruthenium. These complexes also have a significant interaction with DNA, comparable to that of cisplatin.Figure optionsDownload as PowerPoint slide