Isomerization reaction dynamics and equilibrium at the liquid-vapor interface of water.  A molecular-dynamics study.
The gauche-trans isomerization reaction of 1,2-dichloroethane at the liquid-vapor interface of water is studied using molecular-dynamics computer simulations.  The solvent bulk and surface effects on the torsional potential of mean force and on barrier recrossing dynamics are computed.  The isomerization reaction involves a large change in the electric dipole moment, and as a result the trans/gauche ratio is considerably affected by the transition from the bulk solvent to the surface.  Reactive flux correlation function calculations of the reaction rate reveal that deviation from the transition-state theory due to barrier recrossing is greater at the surface than in the bulk water.  This suggests that the system exhibits non-Rice-Ramsperger-Kassel-Marcus behavior due to the weak solvent-solute coupling at the water liquid-vapor interface.
Benjamin
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Department of Chemistry, University of California, Santa Cruz 95064, USA.
Pohorille
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D002244:Carbon / Q000737:chemistry; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002713:Chlorine / Q000737:chemistry; D005025:Ethylene Dichlorides / Q000737:chemistry*; D007536:Isomerism; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D012997:Solvents / Q000737:chemistry*; D055672:Static Electricity; D014867:Water / Q000737:chemistry*
D005025:Ethylene Dichlorides; D012997:Solvents; D014867:Water; D002713:Chlorine; C024565:ethylene dichloride; D002244:Carbon