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Research is done on photoexcited 7-hydroxy-8-(N-morpholinomethyl)quinoline (HMMQ) which has previously been shown to transform from the excited enol form E* into the excited keto form K* in a number of consecutive elementary processes involving formation of an excited zwitterionic form Z* and rotational Brownian motion of the morpholino group which acts as a proton carrier and gets into motion only if its initial intramolecular H-bond is broken thermally. more...

The predictive reliability of calculations of the excitation energies, geometries, and vibration frequencies for the lower singlet states of NCCCCN is tested. Their performance encourages confidence in the predictions for the so far unanalyzed first singlet transition of NCCCCN. more...

The rate constant curves k(E) for the formation of C(sub 7)H(sub 7)(super +) ions by methyl loss from energy selected ethylbenzene and o-xylene ions were determined over a range from 10(super 3) s (super -1) to 5 x 10(super 6)s(super -1). The C(sub 7)H(sub 7)(super +1) ions formed at the threshold have the structure of benzylium ions for ethylbenzene and that of tropylium ions for the o-xylene. more...

The results of classical trajectory calculations on the sticking of hyperthermal CO to the basal plane (0001) face of ice I(sub h) are presented. The molecular dynamics calculations predict that the average binding energy of the absorbed CO is 4.33 kJ/mol with a maximum value of 10.4 kJ/mol. more...

The long-timescale behavior of adsorbed carbon monoxide on the surface of amorphous water ice is studied under dense cloud conditions by means of off-lattice, on-the-fly, kinetic Monte Carlo simulations. It is found that the CO mobility is strongly influenced by the morphology of the ice substrate. Nanopores on the surface provide strong binding sites, which can effectively immobilize the adsorbates at low coverage. As the coverage increases, these strong binding sites are gradually occupied leaving a number of admolecules with the ability to diffuse over the surface. Binding energies and the energy barrier for diffusion are extracted for various coverages. Additionally, the mobility of CO is determined from isothermal desorption experiments. Reasonable agreement on the diffusivity of CO is found with the simulations. Analysis of the 2152 cm–1 polar CO band supports the computational findings that the pores in the water ice provide the strongest binding sites and dominate diffusion at low temperatures. [ABSTRACT FROM AUTHOR] more...