title: Mono-, di-, and tetranuclear ruthenium(II) complexes containing 3-(pyridin-2-yl)-as-triazino[5,6-f]1,10-phenanthroline: synthesis, characterization, and electrochemical and photophysical properties.
abstract: Mono-, di-, and tetranuclear Ru(II) polypyridine complexes based on the bridging ligand pdtp, where pdtp is 3-(pyridin-2-yl)-as-triazino[5,6-f]1,10-phenanthroline, have been synthesized and characterizated. This asymmetric bridging ligand is composed of two nonequivalent coordinating sites: one involves the phenanthroline moiety, and the other one involves the pyridyltriazine moiety. Electrochemical data show that the first redox process in these complexes is pdtp based and the metal-metal interaction in di- and tetranuclear complexes is very weak. The two oxidations (+1.41 and +1.56 V vs SCE) observed in dinuclear complex 2 are mainly ascribed to the different coordination environments of two metal centers. Absorption spectra are essentially the sum of the spectra of the component monometallic species. The emission spectra are measured both at room temperature and at 80 K in a 4:1 (v/v) EtOH/MeOH matrix. The complexes all display luminescence properties which are close to that featured by the parent [Ru(phen)(3)](2+) species. It is also noted that center-to-periphery energy transfer occurs in the dendritic tetranuclear complex 3.
authors.affiliation: State Key Laboratory of Optoelectronic Materials and Technologies/Department of Chemistry, Zhongshan University, Guangzhou 510275, P. R. China. ceschh@zsu.edu.cn
authors.forename: Hui
authors.initials: H
authors.lastname: Chao
authors.forename: Zhi-Ren
authors.initials: ZR
authors.lastname: Qiu
authors.forename: Li-Rong
authors.initials: LR
authors.lastname: Cai
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.forename: Xiao-Yuan
authors.initials: XY
authors.lastname: Li
authors.forename: Kam-Sing
authors.initials: KS
authors.lastname: Wong
authors.forename: Liang-Nian
authors.initials: LN
authors.lastname: Ji