Muonium Adducts of the Nitro Group: Muoxynitroxides

✍ Scribed by Christopher J. Rhodes; Harry Morris; Christopher A. Scott; Ivan D. Reid; Emil Roduner

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 330 KB
• Volume: 35
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/(sici)1097-458x(199706)35:6<357::aid-omr100>3.0.co;2-q

✦ Synopsis

Implantation of positive muons in liquid samples of nitroalkanes leads to radicals, detectable by the transverse Ðeld muon spin rotation (TF-lSR) technique, with small hyperÐne couplings (ca. 26 MHz). The results indicate that muonium has added to one of the oxygen atoms of the nitro group and that the bound muon remains close to the "nodalÏ region of the nitrogen orbital, which contributes to the SOMO. This is a consequence of p-bonding in 2p z the OÈNÈO(Mu) unit, which is maximally preserved. An abrupt change is found for the nitrobenzene adduct, in which the coupling is raised to 37.14 MHz. Semi-empirical (PM3) calculations provide an explanation for this in terms of the di †erent geometries of and radicals, the former being bent at the nitrogen centre RNO 2 HÕ PhNO 2 HÕ while is planar. When is located in NaX zeolite, its coupling is increased ; this is thought to be PhNO 2 HÕ PhNO 2 HÕ due to the electrostatic Ðeld from Na' cations.