Chemical reduction of the dinuclear cation [Tc-2(CH3CN)(10)](4+) in acetonitrile results in scission of the metal-metal triple bond to produce two Tc(CH3CN)(5) fragments linked together via a mu,eta(1),eta-acetonitrile ligand. The Tc(I)-Tc(II) mixed-valent compound [Tc-2(mu,eta(1),eta(2)-CH3CN) (CH3CN)(CH3CN)(10)][BF4](3) (1) was isolated as a red-brown solid in 70% yield using cobaltocene as a reductant. Lower yields (53%) were obtained when the reduction was carried out with zinc. The crystal structure of 1.0.83 CH3CN reveals that the Tc atoms are separated by a distance of 4.04(2) Angstrom consistent with the complete lack of any metal-metal bonding, Compound 1 has been fully characterized by a variety of spectroscopic techniques including H-1 NMR, UV-Vis and IR spectroscopies as well as cyclic voltammetry. Crystal data at -60 degrees C for 1.0.83CH(3)CN: triclinic space group P (No. 2), a = 12.658(4), b = 16.513(4), c = 19.495(6) Angstrom, alpha = 90.21(2), beta = 99.33(3), gamma = 90.18(3)degrees, V = 4020(2) Angstrom(3), Z = 4. (C) 1997 Elsevier Science S.A.
