Preparation of Rhenium(I) and Rhenium(II) Amine Dinitrogen Complexes and the Characterization of an Elongated Dihydrogen Species.
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.
Chin
R. Martin
RM
Departments of Chemistry, University of Virginia, Charlottesville, Virginia 22901, and University of Toronto, 80 Saint George Street, Toronto, Ontario, M5S 3H6 Canada.
Barrera
Joseph
J
Dubois
Raymond H.
RH
Helberg
Lisa E.
LE
Sabat
Michal
M
Bartucz
Tanya Y.
TY
Lough
Alan J.
AJ
Morris
Robert H.
RH
Harman
W. Dean
WD