SYNTHESIS AND REACTIVITY OF (ETA-5-C5H5)OS(N)(CH2SIME3)2, THE 1ST CYCLOPENTADIENYL NITRIDO TRANSITION-METAL COMPLEX

The first cyclopentadienyl-nitrido complexes of a transition metal were prepared by the reactions between [NBu(n)4][Os(N)Cl2(CH2SiMe3)2] and either NaC5H5 or LiC5Me5. The complexes (eta-5-C5H5)Os(N)(CH2SiMe3)2 and (eta-5-C5Me5)Os(N)(CH2SiMe3)2 were characterized by spectroscopic techniques and elemental analysis. They are soluble in organic solvents, volatile, and stable to air and water. The nitrogen atom in (eta-5-C5H5)Os(N)(CH2SiMe3)2 is a ''soft'' Lewis base. It binds reversibly to BF3 in solution, forming a 1:1 adduct. With silver(I) salts, a 2:1 adduct is formed. The silver-bridged complex {[(eta-5-C5H5)Os(CH2SiMe3)2]2(mu-NAgN)}{BF4} was isolated in good yield from the reaction between (eta-5-C5H5)Os(N)(CH2SiMe3)2 and AgBF4 and was structurally characterized. Crystal data for Os2AgSi4F4N2C26BH54 are a = 15.348 (3) angstrom, b = 18.272 (3) angstrom, c = 14.114 (2) angstrom, beta = 91.76 (1)degrees, V = 3956 (2) angstrom 3, rho = 1.817 g/cm3, mu = 70.56 cm-1, space group = P2(1)/c (C5(2h)), and Z = 4. Final agreement factors are R = 0.065 and R(w) = 0.078. The nitrido complex is displaced from silver by PPh3 but not by Me2NCH2CH2NMe2. Alkylation of the nitrogen atom in (eta-5-C5H5)Os(N)(CH2SiMe3)2 and CH3OSO2CF3 produced an alkylimido complex, [(eta-5-C5H5)Os(NMe)-(CH2SiMe3)2][OSO2CF3].