title: The first dinuclear copper(II) and zinc(II) complexes containing novel Bis-TACN: syntheses, structures, and DNA cleavage activities.
abstract: Two novel binuclear complexes [Cu(2)(L)].(ClO(4))(2) (1) and [Zn(2)(L)].(ClO(4))(2) (2) were synthesized and crystallographically characterized {L = 1(4),5(4)-dimethyl-1(2),5(2)-dihydroxy-1(1,3),5(1,3)-dibenzene-3(1,4),7(1,4)-di-1,4,7-triazacyclononane}. The cation [Cu(2)(L)](2+) structure of 1 is similar to that of [Zn(2)(L)](2+) of 2. The central ion is bridged by the di-phenoxo of L and lies in a close to perfect square pyramidal geometry. 1 and 2 crystallize in the triclinic space group P1. The two complexes effectively promote the cleavage of plasmid DNA in the presence of activating agents at physiological pH and temperature. The pseudo-Michaelis-Menten kinetic parameters k(cat) = 1.61 h(-1), K(m) = 1.35 x 10(-5) M for complex 1 in the presence of mercaptoethanol; k(cat) = 2.48 h(-1), K(m) = 5.5 x 10(-5)M for complex 2 in the presence of hydrogen peroxide were obtained. The mechanism of plasmid DNA cleavage was studied by adding standard radical scavengers. DNA cleavage reaction by the binuclear Zn(II)/H(2)O(2) system is a hydrolytic mechanism.
authors.affiliation: Department of Chemistry, Nankai University, Weijin Road 94, Tianjin, 300071, P. R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Qian
authors.forename: Wen
authors.initials: W
authors.lastname: Gu
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.forename: Fengxian
authors.initials: F
authors.lastname: Gao
authors.forename: Li
authors.initials: L
authors.lastname: Feng
authors.forename: Shiping
authors.initials: S
authors.lastname: Yan
authors.forename: Daizheng
authors.initials: D
authors.lastname: Liao
authors.forename: Peng
authors.initials: P
authors.lastname: Cheng
mesh_terms: D001372:Aza Compounds / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D003408:Cresols / Q000737:chemistry; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry*; D004996:Ethidium / Q000737:chemistry; D007202:Indicators and Reagents; D007700:Kinetics; D008024:Ligands; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000138:chemical synthesis*; D010880:Piperidines / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D015032:Zinc / Q000737:chemistry*
chemical_list: D001372:Aza Compounds; D003408:Cresols; D007202:Indicators and Reagents; D008024:Ligands; D009942:Organometallic Compounds; D010880:Piperidines; C482777:triazacyclononane; C032538:4-cresol; D003300:Copper; D004247:DNA; D004996:Ethidium; D015032:Zinc