@article {1121,
	title = {Theoretical studies of alkyl radicals in the NaY and HY zeolites},
	journal = {J. Phys. Chem. A},
	volume = {109},
	number = {32},
	year = {2005},
	note = {ISI Document Delivery No.: 954TRTimes Cited: 8Cited Reference Count: 68},
	month = {Aug},
	pages = {7242-7250},
	type = {Article},
	abstract = {<p>Interplay of quantum mechanical calculations and experimental data on hyperfine coupling constants of ethyl radical in zeolites at several temperatures was engaged to study the geometries and binding energies and to predict the temperature dependence of hyperfine splitting of a series of alkyl radicals in zeolites for the first time. The main focus is on the hyperfine interaction of alkyl radicals in the NaY and HY zeolites. The hyperfine splitting for neutral free radicals and free radical cations is predicted for different zeolite environments. This information can be used to establish the nature of the muoniated alkyl radicals in the NaY and HY zeolites via mu SR experiments. The ration hyperfine coupling constants of the ethane radical cation in these zeolites are very large with relatively little dependence on temperature. It was found that the intramolecular dynamics of alkyl free radicals are only weakly affected by their strong binding to zeolites. In contrast, the substrate binding has a significant effect on their intermolecular dynamics.</p>},
	keywords = {CYCLOHEXADIENYL RADICALS, DENSITY-FUNCTIONAL CALCULATIONS, ELECTRON-SPIN-RESONANCE, ethyl, GAS-PHASE, HYPERFINE COUPLING-CONSTANTS, INTERNAL-ROTATION, INTRAMOLECULAR MOTION, METHYL, REORIENTATIONAL DYNAMICS},
	isbn = {1089-5639},
	url = {<Go to ISI>://000231178300029},
	author = {K. Ghandi* and Zahariev, F. E. and Wang, Y. A.}
}
@article {375,
	title = {Hyperfine and host-guest interactions of the Mu-cyclohexadienyl radical in NaY zeolite},
	journal = {Journal of Physical Chemistry B},
	volume = {106},
	number = {25},
	year = {2002},
	note = {ISI Document Delivery No.: 565EUTimes Cited: 8Cited Reference Count: 88},
	month = {Jun},
	pages = {6395-6407},
	type = {Article},
	abstract = {The adsorption and dynamical behavior of the muonated cyclohexadienyl radical (C(6)H(6)Mu) in NaY zeolite, formed by muonium (Mu) addition on adsorbed benzene. was investigated by the muon spin resonance (muSR) technique, primarily at loadings of 2-3 C6H6 molecules per supercage of NaY. The dynamics of this radical are expected to be the same as its isotopic analogue, C6H7, for which there are no similar data available. Both TF-muSR and ALC-muSR spectra were recorded, with the most detailed information provided by the positions and line widths of the avoided level crossing resonances. In concert with H-2 NMR, neutron diffraction and molecular dynamics studies of the parent benzene molecule, as well as current theoretical calculations, the dominant adsorption site for the C(6)H(6)Mu radical is believed to be the S-II Na cation, within a supercage, which gives rise to three observed ALC lines, corresponding to two different orientations for the muon (proton) of the CHMu methylene group: pointing toward (endo) and away (exo) from the Na cation. The cation interaction gives rise to unprecedentedly large (approximate to20\%) shifts in hyperfine coupling constants, indicative of a strong bond formed with the T electrons of the C(6)H(6)Mu radical. An additional but weaker resonance line is also seen, which is interpreted as being due to adsorption at the window sites between supercages. The ALC lines associated with the CH,,Mu radical bound to both the Na cation and window sites are all broad, approximate to1 kG, change little with temperature and exhibit mainly static line shapes over the whole temperature range studied, from 3 to 322 K. This indicates a much stronger host-guest interaction for C(6)H(6)Mu, particularly with the Na cation. than is known for benzene, to the extent that this site acts as an effective trap for the free radical, over the critical muSR time scale of 50 ns.},
	keywords = {AROMATIC-MOLECULES, ELASTIC NEUTRON-SCATTERING, GAS-PHASE, H-2 NMR, MAGNETIC-RESONANCE, MOLECULAR-DYNAMICS, RAY-POWDER DIFFRACTION, REORIENTATIONAL DYNAMICS, SODIUM-Y ZEOLITE, SPIN RELAXATION},
	isbn = {1520-6106},
	url = {<Go to ISI>://000176356700007},
	author = {Fleming, Donald G. and Shelley, M. Y. and Arseneau, D. J. and Senba, M. and Pan, J. J. and Roduner, E.}
}
@article {4728,
	title = {Reorientational dynamics of aza-cyclohexadienyl radicals in pyridinium tetrafluoroborate},
	journal = {Physica B-Condensed Matter},
	volume = {289},
	year = {2000},
	note = {ISI Document Delivery No.: 330GBTimes Cited: 8Cited Reference Count: 128th International Conference on Muon Spin Rotation, Relaxation and ResonanceAUG 30-SEP 03, 1999LES DIABLERETS, SWITZERLANDEuropean Phys Soc, Paul Scherrer Inst, Eidgenoss Tech Hochschule, Univ Zurich, European Sci Fdn, Swiss Natl Sci Fdn, Neue Aargauer Bank, Sauerstoffwerk Lenzburg AG, Hamamatsu Photon, EG \& G Berthold GmbH \& Co KG, Prophysik AG, Kroger \& Co, Wenger SA, Alcatel Hochvakuum Tech GmbH, Sunrise AG, Dramer AG, Automobil \& Motoren AG},
	month = {Aug},
	pages = {607-611},
	type = {Proceedings Paper},
	abstract = {{Pyridinium tetrafluoroborate is a ferroelectric with a paraelectric-ferroelectric phase transition of second order, which is exceptional for multidirectional ferroelectrics, Avoided-level-crossing muon-spin resonance has been used to show that the Mu substituted aza-cyclohexadienyl radical derived from the pyridinium ions undergoes fast uniaxial rotation around the axis perpendicular to the molecular plane, confirming earlier results by Czarnecki et al. The changes in reorientational dynamics between 239 and 244 K also verify the existence of a phase transition in this range, as found by Czarnecki. Furthermore, the results give strong evidence that superimposed on the rotation there is a wobbling motion of the rotational axis which freezes in at the first transition temperature},
	keywords = {avoided-level-crossing muon-spin resonance, cyclohexadienyl radical, MAGNETIC-RESONANCE, PHASE-TRANSITION, pyridinium, REORIENTATIONAL DYNAMICS, TETRAFLUOROBORATE, VARIANT},
	isbn = {0921-4526},
	url = {<Go to ISI>://000087953500159},
	author = {Beck, B. and Roduner, E. and Dilger, H. and Czarnecki, P. and Fleming, Donald G. and Reid, I. D. and Rhodes, C. J.}
}
