Showing papers by "Jianying Zhou published in 1999"

Interaction of polypyridyl ruthenium(II) complexes containing non-planar ligands with DNA

Abstract: 2-(2-Chlorophenyl)imidazo[4,5-f]1,10-phenanthroline (CIP) or 2-(2-nitrophenyl)imidazo[4,5-f]1,10-phenanthroline (NIP) and their complexes [Ru(bpy)2(CIP)]2+ and [Ru(bpy)2(NIP)]2+ (bpy = 2,2′-bipyridine) have been synthesized and characterized. The binding of the two complexes to calf thymus DNA has been investigated with spectrophotometric methods and viscosity measurements. The experimental results indicate that the two complexes bind to DNA through a partial intercalative mode that is different from the bonding mode for their parent compound, [Ru(bpy)2(PIP)]2+ (PIP = 2-phenylimidazo[4,5-f]1,10-phenanthroline). The crystal structure of [Ru(bpy)2(CIP)][ClO4]2·2H2O was determined by X-ray diffraction analysis; the imidazo[4,5-f]1,10-phenanthroline moiety is not coplanar with the 2-chlorophenyl ring, having a dihedral angle of 44.5° in the CIP.

Syntheses, characterization and third order non-linear optical properties of the ruthenium(II) complexes containing 2-phenylimidazo[4,5-f][1,10]phenanthroline derivatives†

Abstract: The ruthenium(II) complexes [Ru(dmb)2(LH)][ClO4]2 [dmb = 4,4′-dimethyl-2,2′-bipyridine; LH = 2-(4-nitrophenyl)imidazo[4,5-f][1,10]phenanthroline (PNOPH), 2-(3-nitrophenyl)imidazo[4,5-f][1,10]phenanthroline (MNOPH) and 2-(2-nitrophenyl)imidazo[4,5-f][1,10]phenanthroline (ONOPH)] and their deprotonated complexes have been synthesized and characterized. The electrochemical behaviour of these complexes were examined and compared to that of [Ru(dmb)3]2+. Non-linear optical (NLO) properties of the complexes were investigated using Z-scan techniques. All of the complexes exhibit both NLO absorption and self-defocusing effect (n2 = –0.79 × 10–17 to –1.44 × 10–17 m2 W–1, α2 = 3.00 × 10–11 to 7.09 × 10–11 m W–1, [M] = 5 × 10–5 mol dm–3 in acetonitrile solution). The corresponding effective NLO susceptibilities |χ (3)| of the complexes are 2.86 × 10–12 to 5.07 × 10–12 esu. The results indicate that the substitution and deprotonation of the ligand have an effect on the NLO properties of the complexes. Finally, the crystal structure of [Ru(dmb)2(PNOP)][ClO4]·H2O·0.5C6H6 was determined by X-ray diffraction analysis; it contains two twisted dmb ligands and the bidentate ligand PNOP with torsional angles between each dmb ring pair of 3.4 and 8.7°.

Synthesis, structure and DNA-binding studies on the 2-(3-chlorophenyl)imidazo[4,5-f]1,10-phenanthroline-bis(2,2′-bipy ridine)-ruthenium(II) complex

Abstract: A new polypyridyl ligand, MCP {MCP = 2-(3-chlorophenyl)imidazo[4,5-f]1,10-phenanthroline} and its ruthenium(II) complex, [Ru(bpy)2(MCP)](ClO4)2· 0.5MeCN (bpy = 2,2′-bipyridine), have been synthesized and characterized. The structure of the complex was determined by single crystal X-ray diffraction techniques. The MCP ligand is essentially planar and the stacking interactions between the ligands were observed in the crystal. [Ru(bpy)2(MCP)]2+ can strongly bind to Calf thymus DNA through intercalation of MCP ligand. The Cl substitute group has no significant effect on the spectral properties and DNA-binding behaviour of the complex.