{Ru(CO)x}-core terpyridine complexes: Lysozyme binding affinity, DNA and photoinduced carbon monoxide releasing properties

Abstract

Reaction of 4′-(2-pyridyl)-2,2′:6′,2″-terpyridine (LPY) and 4′-(4-phenylmorpholine)-2,2′:6′,2″-terpyridine (Lmorph) with {[RuCl2(CO)3]}2 in methanol affords [RuCl2(LPY-κ2N1N2)(CO)2] (1) and a mixture of [RuCl2(Lmoph-κ2N1N2)(CO)2]/[RuCl2(Lmorph-κ3N1N2N3)(CO)] (2), respectively. Their photoactivatable CO releasing properties are investigated upon the exposure to light source at 365 nm. One CO molecule is released from 1 at the excitation wavelength 365 nm, while the ligand changes its bidentate mode into the meridional tridentate one. The illumination profile and the influence of the uncoordinated pyridine arm on CO release are examined by solution 1H and 13C NMR spectroscopy. The electronic transitions are studied by TDDFT. The DNA and hen white egg lysozyme binding affinity of the complexes are studied by UV/Vis. and electrospray ionization mass spectrometry. Stable lysozyme complexes, capable of photo induce CO, are formed via the loss of the labile chloride ligands or terpyridine moiety.