651706-52-4Relevant academic research and scientific papers
Reactivity of the Hydrido/Nitrosyl Radical MHCl(NO)(CO)(P iPr3)2, M = Ru, Os
Marchenko, Alexei V.,Vedernikov, Andrei N.,Dye, David F.,Pink, Maren,Zaleski, Jeffrey M.,Caulton, Kenneth G.
, p. 351 - 360 (2004)
The reaction of equimolar NO with the 16 electron molecule RuHCl(CO)L 2 (L = PiPr3) proceeds, via a radical adduct RuHCl(CO)(NO) L2, onward to form RuCl(NO)(CO)L2 (X-ray structure determination) and RuHCl(HNO)(CO)L2, in a 1:1 mole ratio. The HNO ligand, bound by N and trans to hydride, is rapidly degraded by excess NO. The osmium complex behaves analogously, but the adduct has a higher formation constant, permitting determination of its IR spectrum; both MHCl(CO)(NO)L2 radicals are characterized by EPR spectroscopy, and DFT calculations on the Ru system show it to have a half-bent Ru-N-O unit with the spin density mainly on nitrogen. DFT (PBE) energies rule out certain possible mechanistic steps for forming the two products. A survey of the literature leads to the hypothesis that NO should generally be considered as a (neutral) Lewis base (2-electron donor) when it binds to a 16 electron complex which is resistant to oxidation or reduction, and that the resulting N-centered radical has a M-N-O angle of ～140°, which distinguishes it from NO- (bent at + (>170°).
