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Atom Transfer Radical Polymerization of Functionalized Vinyl Monomers Using Perylene as a Visible Light Photocatalyst
Published on: April 22, 2016
Intramolecular hydrogen migration in alkylperoxy and hydroperoxyalkylperoxy radicals: accurate treatment of hindered
Sandeep Sharma1, Sumathy Raman, William H Green
1Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Abstract:
We have calculated the thermochemistry and rate coefficients for stable molecules and reactions in the title reaction families using CBS-QB3 and B3LYP/CBSB7 methods. The accurate treatment of hindered rotors for molecules having multiple internal rotors with potentials that are not independent of each other can be problematic, and a simplified scheme is suggested to treat them. This is particularly important for hydroperoxyalkylperoxy radicals (HOOQOO). Two new thermochemical group values are suggested in this paper, and with these values, the group additivity method for calculation of enthalpy as implemented in reaction mechanism generator (RMG) gives good agreement with CBS-QB3 predictions. The barrier heights follow the Evans-Polanyi relationship for each type of intramolecular hydrogen migration reaction studied.
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