Upon homolysis the photoinduced alkyl and cob(II)alamin radicals may recombine or escape the solvent cage to form solvent separated radical pairs which do not recombine in the bulk by the 9ns time limit of these experiments. Recombination can be monitored directly via the oxidation state of the cobalt atom. The neutral alkyl radical is a paradigm for small particle escape and diffusive motion in a liquid. The escape behavior is similar for adenosyl, ethyl, and propyl radicals indicating that hydrogen bonding with the solvent is not a major influence. The methyl radical appears to dissociate from the cobalamin with excess kinetic energy. Preliminary analysis is presented suggesting the escape is not adequately modeled by the steady state diffusive hydrodynamic theory. To explain the discrepancy of escape in different environments an outline of planned analysis is presented.Siegman, A.E., Lasers. 1986, Sausalito, California: University Science Books. 27. Instruction Manual for Model TS Ti:Sapphire laser kit. 2002, Kapteyn-Murnane Laboraties L.L.C.: Boulder, CO. 28. Palmer, C, Diffraction Grating Handbook. 5 ed .
|Title||:||Ultrafast Transient Absorption Studies of Environment Influence on the Photolysis of B12 Complexes and the Subsequent Recombination and Escape of Caged Radicals|
|Author||:||Andrew B. Stickrath|
|Publisher||:||ProQuest - 2008|