Premium
Muonium Adducts of the Nitro Group: Muoxynitroxides
Author(s) -
Rhodes Christopher J.,
Morris Harry,
Scott Christopher A.,
Reid Ivan D.,
Roduner Emil
Publication year - 1997
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/(sici)1097-458x(199706)35:6<357::aid-omr100>3.0.co;2-q
Subject(s) - chemistry , muonium , muon , adduct , nitrobenzene , radical , muon spin spectroscopy , nitro , lone pair , group (periodic table) , crystallography , hyperfine structure , nitrogen , electron paramagnetic resonance , neon , photochemistry , atomic physics , nuclear magnetic resonance , molecule , organic chemistry , hydrogen , nuclear physics , catalysis , alkyl , physics , argon
Implantation of positive muons in liquid samples of nitroalkanes leads to radicals, detectable by the transverse field muon spin rotation (TF‐μSR) technique, with small hyperfine 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 ‘nodal’ region of the nitrogen 2p z orbital, which contributes to the SOMO. This is a consequence of π‐bonding in the O—N—O(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 different geometries of RNO 2 H · and PhNO 2 H · radicals, the former being bent at the nitrogen centre while PhNO 2 H · is planar. When PhNO 2 H · is located in NaX zeolite, its coupling is increased; this is thought to be due to the electrostatic field from Na + cations. © 1997 John Wiley & Sons, Ltd.