title: Highly electrophilic (salen)ruthenium(VI) nitrido complexes.
abstract: A series of cationic ruthenium(VI) nitrido species containing the cyclohexyl-bridged salen ligand (L) and its derivatives, [RuVI(N)(L)]+, have been prepared by treatment of [NBun4][RuVI(N)Cl4] with H2L in methanol. The structure of [RuVI(N)(L)](ClO4) (1a) has been determined by X-ray crystallography, d(RuN) = 1.592 A. In solvents such as DMF or DMSO, [RuVI(N)(L)]+ undergoes a facile N...N coupling reaction at room temperature to produce N2 and [RuIII(L)(S)2]+ (S = solvent). 1a reacts rapidly with secondary amines to produce diamagnetic RuIV-hydrazido(1-) species, [RuIV(N(H)NR2)(L)(HNR2)]+. The reaction with morpholine is first order in RuVI and second order in morpholine with k(CH3CN, 25 degrees C) = 2.08 x 106 M-2 s-1. This rate constant is over 4 orders of magnitude larger than that of the corresponding reaction of the electrophilic osmium nitride, trans-[OsVI(N)(tpy)(Cl)2]+, with morpholine. The structure of [Ru(NHNC4H8)(L)(NHC4H8)](PF6)2 has been determined by X-ray crystallography, the Ru-N(hydrazido) distance is 1.940 A, and the Ru-N-N angle is 129.4 degrees .
authors.affiliation: Department of Biology and Chemistry, City University of Hong Kong, Tat Che Avenue, Hong Kong, China.
authors.forename: Wai-Lun
authors.initials: WL
authors.lastname: Man
authors.forename: Tsz-Man
authors.initials: TM
authors.lastname: Tang
authors.forename: Tsz-Wing
authors.initials: TW
authors.lastname: Wong
authors.forename: Tai-Chu
authors.initials: TC
authors.lastname: Lau
authors.forename: Shie-Ming
authors.initials: SM
authors.lastname: Peng
authors.forename: Wing-Tak
authors.initials: WT
authors.lastname: Wong