title: Preparation of Rhenium(I) and Rhenium(II) Amine Dinitrogen Complexes and the Characterization of an Elongated Dihydrogen Species.
abstract: A series of rhenium(I) dinitrogen complexes were prepared containing predominantly amine ligands. On the basis of infrared and electrochemical data, a system was selected that was anticipated to be a suitable precursor for an elongated dihydrogen complex. Upon oxidation by AgOTf, the dinitrogen ligand of fac-[Re(PPh(3))(PF(3))(dien)(N(2))](+) (3) is replaced with triflate to generate 13, fac-[Re(PPh(3))(PF(3))(dien)(OTf)]OTf, a convenient precursor to rhenium(II) and rhenium(I) amine complexes. Reduction of the rhenium(II) triflate 13 under 1 atm of hydrogen gas generates the complex fac-[Re(dien)(PPh(3))(PF(3))(dien)(H(2))](+) (fac-14). T(1) measurements indicate a dihydrogen species with a H-H distance of 1.38 +/- 0.03 Å. The HD analog displays a J(HD) of 6.7 Hz, corresponding to a H-H distance of 1.31 +/- 0.03 Å, a value in good agreement with that determined from T(1) data and among the largest ever measured for an elongated dihydrogen system.
authors.affiliation: Departments of Chemistry, University of Virginia, Charlottesville, Virginia 22901, and University of Toronto, 80 Saint George Street, Toronto, Ontario, M5S 3H6 Canada.
authors.forename: R. Martin
authors.initials: RM
authors.lastname: Chin
authors.forename: Joseph
authors.initials: J
authors.lastname: Barrera
authors.forename: Raymond H.
authors.initials: RH
authors.lastname: Dubois
authors.forename: Lisa E.
authors.initials: LE
authors.lastname: Helberg
authors.forename: Michal
authors.initials: M
authors.lastname: Sabat
authors.forename: Tanya Y.
authors.initials: TY
authors.lastname: Bartucz
authors.forename: Alan J.
authors.initials: AJ
authors.lastname: Lough
authors.forename: Robert H.
authors.initials: RH
authors.lastname: Morris
authors.forename: W. Dean
authors.initials: WD
authors.lastname: Harman