A. J. DOHENY and A. C. ALBRECHT. Can. J. Chem. 55,2065Chem. 55, (1977. Isothermoluminescence (ITL) and electrophotoluminescence (EPL) resulting from electroncation recombination are measured in a 2-methylpentane-methylcyclohexane glass. The ITL is more characteristic of quantum-mechanical tunnelling and the EPL signal is markedly stronger in this new glass than previous measurements in 3-methylpentane. Quantum-mechanical tunnelling theory is used to predict recombination rates of electrons in the potential field of a cation plus an applied field. Numerical integration of the nonhomogeneous kinetic equations resulting from a distribution of cation-electron separations leads to qualitative and quantitative predictions of the EPL signal that are observed experimentally. Fitting of the theory to experiment supports the conclusions that the angular distribution of the photoelectrons about the cations is close to isotropic, that the electrons active in ITL and EPL on the time scale of minutes are separated about 50 A from their parent cation, and that the trap ionization potential in this nonpolar hydrocarbon glass is in the range of 0.5 to 0.7 eV.A. 3. DOHEYY et A. C. ALBRECHT. Can. J. Chem. 55.2065Chem. 55. (1977. On a mesur6 l'isothermolun~inescence (ITL) et I'tlectrophotoluminescence (EPL) qui se produit a partir de recombinaisons electron-cation dans des verres de methyl-2 pentane et de mCthylcyclohexane. L'ITL est plus caractkristique d'un tunnel de n~ecanique quantique et le signal EPL est beaucoup plus fort dans ce nouveau verre que ceux mesurCs anterieurement dans le methyl-3 pentane. On utilise la theorie des tunnels de mecanique quantique pour predire les vitesses de recombinaison des electrons dans le champ potentiel d'un cation plus un champ appliqui. L'inlCgration numerique des equations cinetiques non-homogenes resultant des distributions des separations cation-electron conduit a des predictions qualitatives et quantitatives du signal EPL qui sont observees exptrimentalement. L'ajustement de la theorie avec les experiences supporte les conclusions voulant que la distribution angulaire des photoClectrons autours de cations est pres de l'isotropique, que les electrons actifs dans 1'ITL et 1'EPL sur une echelle de temps de minutes sont sCparts par environ 50 8, de leur cation parent et finalement que le potentiel d'ionisation de piege dans ce verre hydrocarbone non-polaire est d'environ 0.5 a 0.7 eV.[Traduit par le journal]~.

A variant of the referenced demonstration using crown ethers.

The effect of alkyl free radical stability on the rate of free radical halogenation of hydrocarbons can be convincingly demonstrated by the comparative photobromination of the arenes toluene, ethylbenzene, and cumene.