Access to well-defined Ru(I) and Os(I) metalloradicals

One electron redn. of Ru(II) and Os(II) complexes, [SiP^(iPr)_3]MCl (M = Ru, Os) [SiP^R_3]- ([SiP^R_3]- = (2-R_2PC_6H_4)_3Si-, R = iPr), under dinitrogen atm. yields the first well-defined and thoroughly characterized examples of mononuclear Ru(I) and Os(I) complexes, [SiP^(iPr)_3]M(N_2) (M = Ru, Os). EPR and DFT studies confirm their resp. metalloradical character, and reactivity studies expose both 1-electron and 2-electron redox transformations. In particular, reactions of [SiP^(iPr)_3]M(N_2) (M = Ru, Os) with an orgnanic azide afford the unusual imido/nitrene complexes, [SiP^(iPr)_3]M(NAr) (M = Ru, Os; Ar = C_6H_4CF_3), which possess significant radical character on the 'ArN' moiety.