An Electron-Excessive Nitrosyl Complex:  Reactivity of a Ligand-Centered Radical Leading to Coordinated HNO

• Published in: Inorganic chemistry Vol. 41; no. 16; pp. 4087 - 4089
• Main Authors: Marchenko, Alexei V, Vedernikov, Andrei N, Dye, David F, Pink, Maren, Zaleski, Jeffrey M, Caulton, Kenneth G
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 12.08.2002
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/ic025699j

The reaction of RuHCl(CO)L2 (L = PiPr3) with NO initially forms a 1:1 adduct, shown by DFT calculations and EPR spectroscopy (including the RuD isotopomer) to contain a bent (∠Ru−N−O = 143.9°) nitrosyl where the majority of the spin density is on the nitrosyl nitrogen. This radical adduct transforms further to give equimolar RuCl(NO)(CO)L2 and RuHCl(HNO)(CO)L2, the latter with hydride trans to the nitroxyl ligand HNO. This is the first observation of the synthesis of coordinated HNO from NO itself. DFT calculations lead to the proposal that this H-atom transfer is effected by free NO, and the lifetime of RuHCl(HNO)(CO)L2 is indeed qualitatively dependent on the presence of free NO.