title: A cyanide-bridged trinuclear Fe(II)-Ru(II)-Fe(II) complex with three stable states: synthesis, crystal structures, electronic couplings and magnetic properties.
abstract: Treatment of trans-(Ph-tpy)Ru(PPh(3))(CN)(2) (Ph-tpy = 4'-phenyl-2,2':6',2''-terpyridine, PPh(3) = triphenylphosphine) with 2 equiv of Cp(dppe)Fe(NCCH(3))Br (dppe = bis(diphenylphosphino)ethane) in the presence of NH(4)PF(6) produced a trinuclear cyanide-bridged complex, trans-[Cp(dppe)Fe(CN)(Ph-tpy)Ru(PPh(3))(CN)Fe(dppe)Cp][PF(6)](2) (1[PF(6)](2)). Its one-electron oxidation product (1[PF(6)](3)) and two-electron-oxidation product (1[PF(6)](4)) were obtained by oxidation with (Cp)(2)FePF(6) and AgPF(6), respectively. Firstly, the crystal structures of the cyanide-bridged complexes with three stable states were fully characterized. The reversible electrochemistry measurement of 1(2)(+) shows the presence of a long range intervalence interaction between the external iron centres. Both 1(3)(+) and 1(4)(+) were considered to be Class II mixed valence complexes according to the classification of Robin and Day. Magnetic analysis indicated the presence of a moderately strong antiferromagnetic coupling between the two remote Fe(III) ions across the Fe-NC-Ru-CN-Fe array in 1(4)(+). This proves that the Ru(II)-dicyano complex is a bridging ligand that can transmit electro- and magneto-communication.
authors.affiliation: State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, PR China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Ma
authors.forename: Sheng-Min
authors.initials: SM
authors.lastname: Hu
authors.forename: Chun-Hong
authors.initials: CH
authors.lastname: Tan
authors.forename: Yue-Hong
authors.initials: YH
authors.lastname: Wen
authors.forename: Qi-Long
authors.initials: QL
authors.lastname: Zhu
authors.forename: Chao-Jun
authors.initials: CJ
authors.lastname: Shen
authors.forename: Tian-Lu
authors.initials: TL
authors.lastname: Sheng
authors.forename: Xin-Tao
authors.initials: XT
authors.lastname: Wu