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Mobility of dichloroethyl radicals sorbed in kaolin and silica: a potential model of heterogeneous atmospheric processes

“…The theory, however, is fairly well understood, 9,10 and studies have been made of the intramolecular dynamics of radicals formed by muonium addition to Ph 4 X (X D C, Si, Ge, Pb), 11 and to some metallocenes and benzene-metal complexes, 12 in which the muon acts as a spin probe of torsional motion of the phenyl groups and of the overall motion of the cyclopentadienyl or benzene ring about the metal atom.…”

Rates of motion for free radicals in zeolites as directly measured by longitudinal field muon spin relaxation

“…In addition to the interest in studying hydrocarbon radicals per se, the MuSR approach may be considered as a 'spin-labelling' technique, but one which is particularly appropriate to small molecules, since overall it is merely the addition of this tiny hydrogen atom which provides the spin label, as opposed to the conventional approach of adding a stable 'nitroxide' function, 6 which is as large as benzene itself, and far exceeds being a minor perturbation of the system. Seemingly unconnected are MuSR (R D relaxation measurements of internal molecular motion in radicals, 7,8 specifically rotation of the benzene rings in tetraphenyllead and its group 4 homologues (and in benzene chromium tricarbonyl), and of the cyclopentadienyl rings in metallocenes. The basis of the relaxation method (LFMuSRx) is that when a molecular motional frequency approaches that of the dominant spectral transition in the muon-electron coupled system, there is an increase in the relaxation rate ( ) of the muon spins, as measured in a longitudinal magnetic field (LF), which reaches a maximum when the frequencies are equal.…”

Molecular Motion in Tetraphenyltin Studied by NMR

“…In a recent work, a study of the molecular dynamics of tetraaryl compounds by the mionic resonance (fiSR) was reported [12,13]. The relaxation rate was mea- 0932-0784 / 99 / 0600-0800 $ 06.00 © Verlag der Zeitschrift für Naturforschung, Tübingen • www.znaturforsch.com Unauthenticated Download Date | 5/10/18 9:20 AM sured for X(C 6 H 5 ) 4 where X=Ge, Sn, Pb in the temperature range from 10 to 475 K, and for all compounds the presence of maxima in the dependencies was noted.…”