DNA-binding behavior of ruthenium(II) complexes containing both group 15 donors and 2,2′:6′,2-terpyridine

Tetrafluoroborate salts of cationic ruthenium complexes [Ru(kappa(3)-tpy)(EPh3)(2)Cl](+) (tpy = 2,2':6',2-terpyridine; E = P, 1 or As, 2) containing both the group 15 donor ligands and tpy and their representative substitution products are reported. Weak interaction {C-(HX)-X-... (X = Cl, F and pi) and pi-pi interactions studies revealed the presence of a double helical motif in complex 1, while the complex 2 assumes a single helical motif. Intercalative mode of interaction of the complexes 1 and 2 with calf thymus DNA (ctDNA) has been supported by absorption titration studies. (C) 2004 Elsevier Inc. All rights reserved.