Jump to main content
Jump to site search

Issue 4, 1997
Previous Article Next Article

Effect of media polarity on the photoisomerisation of substitutedstilbene, azobenzene and imine chromophores


The influence of substituents and media polarity on the photoinducedE→Z geometrical isomerisation of the stilbene, azobenzene and N-benzylideneaniline chromophores has been compared and assessed. The efficiency of the process in all three systems is markedly dependent on the presence and characteristics of electron-donor and electron-acceptor substituents at the 4- and 4′-positions. The results are discussed in terms of relaxation of the E-excited singlet state. In the absence of a nitro substituent, relaxation to the S 1 orthogonal state competes effectively with non-productive intramolecular electron transfer; in the presence of a nitro substituent, the T 1 orthogonal state is formed from inter-system crossing. For systems with a 4-nitro and a 4′-electron-donor substituent, access to the triplet state is inhibited by polar solvents promoting formation of the inactive charge-transfer state from the S 1 state, and no isomerisation is observed. Similar effects are observed in both solution and polymer films. Such variations in behaviour have important implications for the utilisation of the chromophores in nonlinear optical phenomena including photorefractivity.

Back to tab navigation

Article type: Paper
DOI: 10.1039/A607980F
Citation: J. Mater. Chem., 1997,7, 625-630
  •   Request permissions

    Effect of media polarity on the photoisomerisation of substituted stilbene, azobenzene and imine chromophores

    N. R. King, E. A. Whale, Fred J. Davis, A. Gilbert and Geoffrey R. Mitchell, J. Mater. Chem., 1997, 7, 625
    DOI: 10.1039/A607980F

Search articles by author