title: Electronic coupling between two cyclometalated ruthenium centers bridged by 1,3,6,8-tetrakis(1-butyl-1H-1,2,3-triazol-4-yl)pyrene.
abstract: A new bridging ligand 1,3,6,8-tetrakis(1-butyl-1H-1,2,3-triazol-4-yl)pyrene (ttapyr) was designed and synthesized by "click" chemistry. This ligand was used to construct a linear dimetallic biscyclometalated Ru(II) complex [(tpy)Ru(ttapyr)Ru(tpy)](2+) and a monometallic complex [(tpy)Ru(ttapyr)](+), where tpy is 2,2':6',2″-terpyridine. The electronic properties of these complexes were studied and compared by electrochemical and spectroscopic methods with the aid of DFT calculations. One-electron oxidation of [(tpy)Ru(ttapyr)Ru(tpy)](2+) with cerium ammonium nitrate produced a mixed-valent complex [(tpy)Ru(ttapyr)Ru(tpy)](3+). The intramolecular electronic coupling between individual metal centers was quantified by the intervalence charge transfer transition analysis. Mixed-valent complex [(tpy)Ru(ttapyr)Ru(tpy)](3+) exhibits a metal-centered rhombic EPR signal at 77 K with an average g factor of 2.203.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Wen-Wen
authors.initials: WW
authors.lastname: Yang
authors.forename: Ren-Hui
authors.initials: RH
authors.lastname: Zheng
authors.forename: Qiang
authors.initials: Q
authors.lastname: Shi
authors.forename: Yu-Wu
authors.initials: YW
authors.lastname: Zhong
authors.forename: Jiannian
authors.initials: J
authors.lastname: Yao