PHOTOPHYSICS AND PHOTOCHEMISTRY OF BIS-2-(9-ANTHRYL)ETHYL GLUTARATE

Abstract— The photochemistry and photophysics of bis‐(2‐(9‐anthryl)ethyl glutarate 2 and 2‐(9‐anthryl) ethyl pivalate 3 have been examined as monomeric models for poly‐2‐(9‐anthryl)ethyl methacrylate 1. The absorption and excitation spectra of 2 show no ground state interaction, but appreciable monomer (51%) and excimer (49%) emission. Delayed monomer and excimer fluorescence are also observed in fluid solution at room temperature. Photolysis of 2 at low temperature produces a photoproduct (44% yield) which is unstable at room temperature and presumably is the head‐to‐head (H‐H) dimer. Steady state irradiation of 2 at room temperature (Λ 350 nm) cleanly produces a head‐to‐tail (H‐T) dimer (6) derived from the singlet state and an additional unidentified adduct (7). The product distribution is concentration dependent, with 6 predominating at high concentrations (> 10−3M). The fluorescence spectra of the broken dimers derived from 6 and 7 indicate that substantial ir overlap exists in the transition state leading to each product. Copyright © 1990, Wiley Blackwell. All rights reserved