title: Quantum amplified isomerization in polymers based on triplet chain reactions.
abstract: 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 approximately 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.
authors.affiliation: Research Laboratories, Eastman Kodak Company, Rochester, New York 14650-2116, USA.
authors.forename: Lorraine
authors.initials: L
authors.lastname: Ferrar
authors.forename: Mark
authors.initials: M
authors.lastname: Mis
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Dinnocenzo
authors.forename: Samir
authors.initials: S
authors.lastname: Farid
authors.forename: Paul B
authors.initials: PB
authors.lastname: Merkel
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Robello