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Triplet-Triplet Energy Transfer in Photocrosslinkable Dendrimers

Published online by Cambridge University Press:  01 February 2011

Seiichi Furumi
Affiliation:
Nanotechnology group, Kansai Advanced Research Center, Communications Research Laboratory
Akira Otomo
Affiliation:
Nanotechnology group, Kansai Advanced Research Center, Communications Research Laboratory
Shiyoshi Yokoyama
Affiliation:
Nanotechnology group, Kansai Advanced Research Center, Communications Research Laboratory PRESTO, Japan Science and Technology Corporation (JST), 588-2 Iwaoka, Nishi-ku, Kobe 651-2492, JAPAN.
Shinro Mashiko
Affiliation:
Nanotechnology group, Kansai Advanced Research Center, Communications Research Laboratory
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Abstract

This report describes the synthesis of photocrosslinkable dendrimers with peripheral cinnamamide residues, which exhibit both photoisomerization and photodimerization, and their photochemical and photophysical properties in dilute solutions and polymer matrices. Photoirradiation with 313 nm gave rise to monotonous decrease in the absorbance of trans-cinnamamide at 270 nm as a result of the photochemical reactions of the cinnamamide residues. Spectral analysis revealed the changes in the photoproduct distribution of trans- and cis-photoisomerized and photodimerized cinnamamide groups to be a function of the exposure energy. In dilute solutions, the first-generation dendrimer displayed preferential formation of cis-isomer of the cinnamamide, whereas the photodimerization took place more favorably for the third- and fifth-generation dendrimers. The photochemical behavior was strongly dependent on the dendrimer generation rather than the concentration, probably due to the extent of steric crowding among the cinnamamide residues at terminal positions. Furthermore, the third- and fifth-generation dendrimers showed capturability of a benzophenone derivative into the macromolecules and triplet-triplet energy transfer in the photocrosslinkable dendrimers. This novel phenomenon of the triplet-triplet energy transfer in the dendritic cavities suggests potential applicability to design and fabricate novel optical and electrical molecular devices.

Type
Research Article
Copyright
Copyright © Materials Research Society 2002

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References

1. Birks, J. B. “Energy migration and transfer”, Photophysics of Aromatic Molecules, (Wiley-Interscience, 1970) pp.518624.Google Scholar
2. Turro, N. J.Energy Transfer”, Modern Molecular Photochemistry, (University Science Books, 1991) pp.296361.Google Scholar
3. Klessinger, M. and Michl, J. “Photophysical Processes”, Excited States and Photochemistry of Organic Molecules, (VCH, 1995) pp.243308.Google Scholar
4. Kuhlbrandt, W. Nature 374, 497 (1995).Google Scholar
5. Baldo, M. A. Thompson, M. E. Forrest, S. R. Nature 403, 750 (2000).Google Scholar
6. Wilson, J. S. Dhoot, A. S. Seeley, A. J. A. B. Khan, M. S. Köhler, A., Friend, R. H. Nature 413, 828 (2001).Google Scholar
7. Förster, T., Disc. Faraday Soc. 27, 7 (1959).Google Scholar
8. Dexter, D. L. J. Chem. Phys. 21, 836 (1953).Google Scholar
9. Adronov, A. and Fréchet, J. M. J., Chem. Comm., 1701 (2000) and references therein.Google Scholar
10. Cohen, M. D. and Schmidt, G. M. J. J. Chem. Soc., 1969 (1964).Google Scholar
11. Egerton, P. L. Pitts, E. Reiser, A. Macromolecules 12, 95 (1981).Google Scholar
12. Jansen, J. F. G. A. Berg, E. M. M. de Brabander-van, Meijer, E. W. Science 266, 1226 (1994).Google Scholar
13. Cooper, A. I. Londono, J. D. Wignall, G. McClain, J. B. Samulski, E. T. Lin, J. S. Dobrynin, A., Rubinstein, M. Burke, A. L. C. Fréchet, J. M. J., DeSimone, J. M. Nature 389, 368 (1997).Google Scholar
14. Zhao, M. Sun, L. Crooks, R. M. J. Am. Chem. Soc. 120, 4877 (1998).Google Scholar
15. Balogh, L. and Tomalia, D. A. J. Am. Chem. Soc. 120, 7355 (1998).Google Scholar
16.Michler's ketone was employed here as a triplet photosensitizer, because its triplet energy (260 kJ mol-1) is closed to that of a trans-cinnamoyl derivative (230 kJ mol-1).Google Scholar
17. Stevelmans, S. Hest, J. C. M. van, Jansen, J. F. G. A. Boxtel, D. A. F. J. van, Berg, E. M. M. de Brabander-van, Meijer, E. W. J. Am. Chem. Soc. 118, 7398 (1996).Google Scholar
18. Minsk, L. M. Smith, J. G. Deusen, W. P. Van, Wright, J. F. J. Appl. Polym. Sci. 2, 302 (1959).Google Scholar