Decalin, activation energy

While the mobilities of electrons were invariably found to be thermally activated in hydrocarbon solvents, those for the holes in cyclohexane and trans decalin were found, if anything, to have a slightly negative activation energy. This had the interesting consequence that for sub-ambient temperatures in trans-decalin, the hole was found to be even more mobile than the electron. 

However, the activation energy drops considerably when at least two phenyl substituents on the cyclopropyl radical provide strong resonance stabilization to the allylic radical resulting from ring opening. Therefore, diphenylcyclopropane peresters or peranhydrides undergo cyclopropyl radical to allyl radical rearrangement, followed by dimerization, in the liquid phase (benzene, ethylbenzene, mesitylene, decaline, benzonitrile etc.) " at 80-... 

Figure 6. Activation energy of the JG relaxation in the glassy state for different isobaric measurements plotted versus the related Tg(P). QN in tristyrene (5% and 10% wt. are indicated by open circles and solid squares, respectively), 5% wt. QN in PS800 (solid triangles), PPGE (solid stars), 5% wt CNBz in tristyrene (open stars), 17% ClBz in decalin from reff ] (solid down triangles). Dashed lines are the predictions according toEq. (3).

If there are two solid phases, the action of carriers should be mentioned first. The carriers, as distinct from the second component of the mixed catalyst, usually do not change the activation energy e. Thus, it was found that on dehydrogenation of decalin on Pt on charcoal e =... 

Activation Energies of Dehydrogenation of Piperidine, Cyclohexane and Decalin Metals of Various Atomic Radii Atomic radius Piperidine Cyclohexane Decalin ... 

Fig. 18 Activation energy of p-relaxation in (a) low-molecular weight glasses and (b) linear polymers vs the cohesion energy or cohesion energy of Kuhn statistical segment, respectively [86, 88,103]. (a) (1) Pentanol (2) isopropylbenzene (3) 5-methyl-3-heptanol (4) decalin (5) 1,1-diphenylpropane (6) diethyl phthalate (7) glycerol (8) 6>-terphenyl (9) hexamethyl disolox-ane (10) tetra-a-methylstyrene (11) pentastyrene. (b) (1) Polyethylene (2) polyisoprene (3) poly(dimethylsiloxane) (4) poly(diethylsiloxane) (5) poly(phenylene oxide) (6) poly(ethylene terephthalate) (7) polytetrafluoroethylene (8) polycarbonate (9) polyamide (10) polypropylene (11) polymethacrylate (12) poly(vinyl fluoride) (13) poly(vinyl acetate) (14) poly(vinyl chloride) (15) poly(vinyl alcohol) (16) poly(methyl methacrylate) (17) poly(diphenyl oxypheny-lene) (18) poly(butyl methacrylate) (19) polystyrene (20) polyacrylonitrile (21) poly(a-methylstyrene) (22) poly(cyclohexyl methacrylate) (23) polyimide I (24) polyimide II (25) poly(metaphenylene isophthalamide) (26) polyisobutylene...

The enthalpy of the H-bonds among the majority of the organic compounds is relatively low (usually within the range of about 20 kJ per one mol of hydrogen bonds) and therefore they can easily be disrupted. In order to demonstrate the presence of lateral interactions in chromatographic system, low-activity adsorbents are most advisable (i.e., those having relatively low specific surface area, low density of active sites on its surface, and low energy of intermolecular analyte-adsorbent interactions, which obviously compete with lateral interactions). For the same reason, the most convenient experimental demonstration of lateral interactions can be achieved in presence of the low-polar solvents (basically those from the class N e.g., n-hexane, decalin, 1,4-dioxane, etc.) as mobile phases. 

The first experimental determination of the inversion barrier of a tertiary arsine was reported in 1971 ". The kinetics of racemization of (/ )-(—)- and (S)-( + )-ll, resolved by the metal complexation method, at 217.6 +0.3 °C in decalin (sealed tube) was determined polarimetrically in the 310-350 nm region. From the kinetic data, by substitution into the Eyring equation, the free energy of activation, AG was calculated to be 175 + 2kJmol at 217.6°C. This energy value corresponds to a half-life for racemization of the arsine of ca 740 h at 200 °C. It had been reported previously that resolved ethylmethylphenylarsine and methyl(n-propyl)phenylarsine showed no detectable loss of optical activity over 10 h at 200 On the basis of photoracemization studies... 

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