Intramolecular Complex Formation and Triplet Energy Transfer in Polynorbornenes Incorporating Benzophenone

Abstract

The photophysical properties of homopolymers (2) and block copolymers (3) prepared by ring-opening metathesis polymerization of norbornenes substituted with benzophenone, naphthalene, and phenanthrene groups (1) have been investigated. When benzophenone is attached to this polynorbornene backbone, its excited state behavior differs from that observed for monomeric benzophenone. A new intramolecular excited state complex can be observed in the transient absorption and emission measurements of the benzophenone-substituted homopolymer. In copolymers bearing benzophenone and naphthalene or phenanthrene substituent blocks, triplet energy transfer from the sensitizer (benzophenone) to the arene is observed. This energy transfer dominates over the intramolecular complexation that characterizes group interactions in the homopolymer.

Fundamentals in the Design of Molecular Electronic Devices: Long-Range Charge Carrier Transport and Electronic Coupling

“…With such compounds, we have used fluorescence spectroscopy and laser flash photolysis to show that both energy and electron migration can easily take place, both along one block and across the interface between blocks ,

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Fast transient absorption spectroscopy of the early events in photoexcited chiral benzophenone–naphthalene dyads

“…Since the first report by Terenin and Ermolaev, benzophenone (BP)/naphthalene (NP) systems have been widely used as models to study inter-and intra-molecular singletsinglet and triplet-triplet energy transfer processes [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Thus, Shizuka and coworkers have intensively investigated the sensitization of the NP triplet by BP, the behavior of the triplet-excited states of BP and NP and their interactions.…”

“…The decay of the triplet state of NP was implied to occur by interaction with ground state BP through a loose sandwich-like structure [9][10][11][12]. This type of quenching, claimed different from electron or energy transfer, is inherent to the excited state interactions of BP and NP triplet states [4][5][6][7][8][9][10][11][12].…”

Synthesis and Photophysical Characterization of Group Transfer Polymers with Pendent Aryl Chromophores

“…By characterizing the relevant excited-state interactions in such macromolecules, valuable structural information concerning backbone rigidity and intramolecular interactions between pendent groups is likely to be attained. For example, in several families of norbornene-derived homopolymers, excimer emission can be suppressed when the interacting chromophores are sterically isolated, i.e., separated from the nearest neighbor by more than one monomer residue. 1c,d, …”