72642-30-9Relevant articles and documents
Quantum amplified isomerization in polymers based on triplet chain reactions
Ferrar, Lorraine,Mis, Mark,Dinnocenzo, Joseph P.,Farid, Samir,Merkel, Paul B.,Robello, Douglas R.
, p. 5683 - 5692 (2008)
(Graph Presented) Photoinitiated triplet quantum amplified isomerizations (QAI) of substituted Dewar benzene derivatives in polymeric media are reported. The quantum efficiencies and the ultimate extents of reactant-to-product conversions increase significantly with the incorporation of appropriate co-sensitizers; compounds whose triplet energies are similar to or lower than that of the sensitizer and close to that of the reactant. These co-sensitizers serve to promote chain-propagating energy transfer processes and thereby increase the action sphere of photosensitization. Isomerization quantum yields increase, as predicted, with increasing concentrations of the reactants and the co-sensitizers. Chain amplifications as large as ~16 and extents of conversion that approach 100% have been achieved. Mechanistic schemes are proposed to account for the dynamics of the inherent energy transfer processes and provide a predictively useful model for the design of a new class of photoresponsive polymers based on changes in the refractive index of the materials.