title: Optically active Ru(II) complexes with a chiral Tröger's base ligand and their interactions with DNA.
abstract: Three stereoisomers of a Ru(II) complex bearing a chiral bis-phenanthroline Tröger's base analogue, TBphen2 (1), have been isolated from the reaction of the enantiomerically pure precursor complex Lambda- (or Delta-) cis-[Ru(phen)2(py)2]2+ (phen=1,10-phenanthroline, py=pyridine) with the racemic mixture of 1. Each stereoisomer of [Ru(phen)2TBphen2]2+ (2) has been characterized by 1H NMR and CD spectroscopy. Electrochemical studies revealed that the redox properties of 2 are not influenced by the stereochemistry, however, the electrochemical oxidation of the metallic center is irreversible because of the diazocine bridge of the TBphen2 ligand. Steady-state emission measurements in the presence of calf thymus DNA showed that the DNA binding of [Ru(phen)2TBphen2]2+ depends on the stereoisomer and is mainly controlled by the absolute configuration of the metal center of the complex. The affinity constant for the stereoisomer Delta-S-2 is 10(2) higher than that for Lambda-S-2 and rac-[Ru(phen)3]2+.
authors.affiliation: Chimie Organique et Photochimie, Université Libre de Bruxelles, CP 160/08, 50 Avenue F.D. Roosevelt, 1050 Bruxelles, Belgium.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Claessens
authors.forename: Frédéric
authors.initials: F
authors.lastname: Pierard
authors.forename: Carole
authors.initials: C
authors.lastname: Bresson
authors.forename: Cécile
authors.initials: C
authors.lastname: Moucheron
authors.forename: Andrée
authors.initials: A
authors.lastname: Kirsch-De Mesmaeker
mesh_terms: D001392:Azocines / Q000737:chemistry*; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D017975:Ruthenium Compounds / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D001392:Azocines; D017975:Ruthenium Compounds; C083830:Troeger's base; D004247:DNA; C427203:calf thymus DNA