Radiolabelled free radicals were formed by the addition of muonium-a radioactive hydrogen atom with a positive muon as its nucleus-to α-pinene, β-pinene, dihydrocarvone, dihydrocarveol and dipentene, each as adsorbed in porous carbon. The radicals were identified using transverse-field muon spin rotation (TF-MuSR) and the activation parameters associated with their reorientational motion were measured using longitudinal-field muon spin relaxation (LF-MuSRx). Two distinct adsorbed fractions were detected in each sample, characterised by activation energies in the range 2-6 kJ/mol and 12-16 J/mol respectively.
WayneR. P.Chemistry of Atmospheres.Clarendon Press, Oxford, 1985.
2.
TurcoR. P.Earth Under Seige.Oxford University Press, Oxford, 1997.
3.
HudsonA., WatermanD., and AlbertiA.Free radicals from biogenic volatile organic compounds. J. Chem. Soc., Perkin Trans., 1995, 2, 2091–2093.
4.
HudsonA., Della BonaM. A., WatermanD., AlbertiA., BenagliaM., and MacciantelliD.Free radicals from cyclic enones: an electron paramagnetic resonance investigation. Part 1. Radicals formed by hydrogen abstraction. J. Chem. Soc., Perkin Trans., 1997, 2, 2487–2490.
5.
HesterR. H., and HarrisonR. M. (eds.). Volatile Organic Compounds in the Atmosphere.Royal Society of Chemistry, Cambridge, 1995.
6.
BansalR. C., DonnetJ.-B., and StoeckliF.Active Carbon.Marcel Dekker, Inc., New York, 1988.
7.
WalkerD. C.Muon and Muonium Chemistry.Cambridge University Press, Cambridge, 1983.
8.
RodunerE.The Positive Muon as a Probe in Free Radical Chemistry. Lecture Notes in Chemistry.Springer, Heidelberg, 1988.
9.
RodunerE.Polarized positive muons probing free radicals: a variant of magnetic resonance. Chem. Soc. Rev., 1993. 22, 337–346.
10.
RodunerE., SchwagerM., and ShelleyM.Muon spin resonance of radicals on surfaces. In: LundA., and RhodesC. J. (eds.), Radicals on Surfaces.Kluwer, Dordrecht, pp. 259–276, 1995.
11.
RhodesC. J.Radiolabelling studies of free radicals using muonium (the second hydrogen radioisotope). Prog. React. Kinet. Mech., 2000, 25, 219–262.
RhodesC. J., DintingerT. C., ReidI. D., and ScottC.A.Spin-labelling studies of benzene sorbed in carbon particles using muonium: a molecular view of sorption by environmental carbons. Magn. Reson. Chem., 2000, 38, S58–S64.
14.
RhodesC. J., RodunerE., and ReidI. D.First direct observation of neutral radicals in a zeolite at ambient temperature. J. Chem. Soc., Chem. Commun., 1993, 512–513.
15.
RhodesC. J., ButcherE. C., MorrisH., and ReidI. D.Mobility of radicals in zeolite catalysts: molecular motion studied by muon spectroscopy. Magn. Reson. Chem., 1995, 33, S134–S146.
16.
RhodesC. J., DintingerT. C., ReidI. D., and ScottC. A.Mobility of dichloroethyl radicals sorbed in kaolin and silica: a potential model of heterogeneous atmospheric processes. Magn. Reson. Chem., 2000, 38, 281–287.
17.
HoffA. (ed.). Advanced EPR, Applications in Biology and Biochemistry.Elsevier, Amsterdam, 1989.
18.
RhodesC. J., and SymonsM. C. R.The formation of β-muonium substituted cyclopentyl and cycloheptyl radicals, and the significance of the A'Λ/AH isotope ratio in relation to the conformations of muonium-substituted alkyl radicals. J. Chem. Soc., Faraday Trans. 1, 1988, 84, 1187–1194.
19.
RodunerE., StrubW., BurkhardP., HochmannJ., PercivalP. W., FischerH., RamosM., and WebsterB. C.Muonium substituted organic free-radicals in liquids – muon electron hyperfine coupling-constants of alkyl and allyl radicals. Chem. Phys., 1982, 67, 275–285.
20.
BonnazolaL., LerayN., and MarxR.Conformational effect in the ESR spectrum of cyclohexyl radicals in adamantane matrix. Chem. Phys. Lett., 1974, 24, 88–90.
21.
OgawaS., and FessendenR.W.Ring inversion in cyclohexyl radical. J. Chem. Phys., 1964, 41, 994–998.
22.
RhodesC. J., and RodunerE.Muonated cyclohexyl radicals. J. Chem. Res. (S), 1991, 196.
23.
HellerC., and McConnellH. M.J. Chem. Phys., 1960, 32, 1535.
24.
RhodesC. J., and RodunerE.Muonium atom addition to hexamethyl (Dewar) benzene: formation of “Dewar” cyclohexadienyl radicals. Chem. Phys. Lett., 1990, 139, 457–461.
25.
RiccoM., De RenziR., GuidiG., BucciC., PodiniP., TedeschiR., and ScottC. A.Muonium radicals in molecular plastic crystals norbornene and bicyclooctene. Hyperfine Interactions, 1986, 32, 757–762.
26.
KochiJ. K.Configurations and conformations of transient alkyl radicals in solution by electron spin resonance spectroscopy. Advances in Free Radical Chemistry, 1975, 5, 189–317.
27.
RhodesC. J., MacraeR. M., and ReidI. D.The first observation of a muonium-carbonyl adduct with a negative muon coupling constant. Chem. Commun., 1999, 2157–2158.
28.
WalkerD. C.Kinetic isotope effects in solution reactions of muonium atoms as H-isotopes. J. Chem. Soc., Faraday Trans., 1998, 94, 1–9.
29.
RhodesC. J., DintingerT. C., and ScottC. A.Rates of motion for free radicals in zeolites: as directly measured by longitudinal field muon spin relaxation. Magn. Reson. Chem., 2000, 38, 62–65.
30.
RhodesC. J., DintingerT. C., and ScottC. A.Sorption of benzene in cation-exchanged zeolite X, as measured by longitudinal field muon spin relaxation (LF–MuSRx). Magn. Reson. Chem., 2000, 38, 729–737.
31.
ChristidesC., CoxS. F. J., DavidW. I. F., MacraeR. M., and PrasidesK.Etudes de la dynamique moleculaire de C60 par relaxation du spin muonique. J. Chim. Phys., 1993, 90, 663–669.
32.
CoxS. F. J.Muon spin relaxation studies of interstitial and molecular motion. Solid State Nucl. Magn. Reson., 1998, 11, 103–121.
33.
CoxS. F. J., and SiviaD. S.Longitudinal muon spin relaxation in muoniumlike systems. Hyperfine Interactions, 1994, 87, 871–976.
34.
CoxS. F. J., and SiviaD. S.Spin-lattice relaxation in hyperfine-coupled systems: applications to interstitial diffusion and molecular dynamics. Appl. Magn. Reson., 1997, 12, 213–226.
35.
JayasooriyaU. A., StrideJ. A., AstonG. M., HopkinsG. A., CoxS. F. J., CottrellS. P., and ScottC. A.Muon spin relaxation as a probe of molecular dynamics of organometallic compounds. Hyperfine Interact., 1997, 106, 27–32.
36.
JayasooriyaU. A., AstonG. M., and StrideJ. A.Molecular dynamics of organometallic compounds using ΛSR. Appl. Magn. Reson., 1997, 13, 165–171.
37.
CarringtonA., and McLachlanA. D.Introduction to Magnetic Resonance.Chapman and Hall, London, 1979.
38.
HarrisR. K.Nuclear Magnetic Resonance Spectroscopy.Pitman, Melbourne, 1983.
39.
BarrerR. M.Zeolites and Clay Minerals as Sorbents and Molecular Sieves.Academic Press, London, 1978.