title: Synthesis, characterization and DNA-binding of novel chiral complexes delta- and lambda-[Ru(bpy)2L]2+ (L = o-mopip and p-mopip).
abstract: Novel chiral Ru(II) complexes [Ru(bpy)2L]2+ (bpy = 2,2-bipyridine; L: o-mopip = 2-(2-methoxylphenyl)imidazo[4,5-f][1,10]phenanthroline, p-mopip = 2-(4-methoxylphenyl)imidazo[4,5-f][1,10]phenanthroline) containing -OCH3 at different positions on the phenyl ring have been synthesized and characterized. The DNA-binding and DNA-photocleavage properties of the complexes were investigated. The theoretical calculations for these complexes were also carried out applying the density functional theory (DFT) method. The experimental results show that: both these two isomer complexes can bind to DNA in an intercalative mode; the DNA-binding affinity of [Ru(bpy)2(p-mopip)] 2 is greater than that of [Ru(bpy)2(o-mopip)] 1; moreover, the DNA-binding affinities of enantiomers delta-1 and delta-2 are all greater than those of lambda-1 and lambda-2, respectively. In addition, a very interesting finding is experimentally obtained, i.e. under a low [DNA]/[Ru] ratio, the emission intensities of delta-1 and lambda-1 are all weaker than those of delta-2 and lambda-2, however, upon a high [DNA]/[Ru] ratio, the emission intensities of both delta-1 and lambda-1 are stronger than those of delta-2 and lambda-2. Such a difference of the emission spectra can be interpreted by the electric effect of substituent on the intercalative ligand. The difference in DNA-binding affinities of these two isomeric complexes can also be reasonably explained by the DFT calculations.
authors.affiliation: School of Chemistry and Chemical Engineering, The Key Laboratory of Gene Engineering of Ministry of Education, State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou 510275, PR China.
authors.forename: Shuo
authors.initials: S
authors.lastname: Shi
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.forename: Kang-Cheng
authors.initials: KC
authors.lastname: Zheng
authors.forename: Xiao-Mei
authors.initials: XM
authors.lastname: Huang
authors.forename: Cai-Ping
authors.initials: CP
authors.lastname: Tan
authors.forename: Lan-Mei
authors.initials: LM
authors.lastname: Chen
authors.forename: Liang-Nian
authors.initials: LN
authors.lastname: Ji
mesh_terms: D015082:2,2'-Dipyridyl / Q000737:chemistry; D001667:Binding, Competitive; D002942:Circular Dichroism; D003198:Computer Simulation; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D004270:DNA, Circular / Q000737:chemistry / Q000378:metabolism; D008163:Luminescent Measurements; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D010618:Phenanthrolines / Q000737:chemistry; D010782:Photolysis; D012428:Ruthenium / Q000737:chemistry; D013057:Spectrum Analysis; D014783:Viscosity
chemical_list: C505403:2-(4-methylphenyl)imidazo(4,5-f)1,10-phenanthroline; D004270:DNA, Circular; D009942:Organometallic Compounds; D010618:Phenanthrolines; C474863:ruthenium(bipyridyl)(2)-2-(2-hydroxyphenyl)imidazo(4,5-f)(1,10)phenanthroline; D015082:2,2'-Dipyridyl; D012428:Ruthenium; D004247:DNA