Hostname: page-component-586b7cd67f-rdxmf Total loading time: 0 Render date: 2024-11-25T17:35:17.789Z Has data issue: false hasContentIssue false

Electronic Properties of a Novel Class of Conjugated Systems: Transition Metal Substituted Oligothiophenes

Published online by Cambridge University Press:  10 February 2011

L. Lancellotti
Affiliation:
Dipartimento di Scienza dei Materiali e INFM, Universita' di Milano, Milano, Italy
R. Tubino
Affiliation:
Dipartimento di Scienza dei Materiali e INFM, Universita' di Milano, Milano, Italy
S. Luzzati
Affiliation:
Istituto di Chimica delle Macromolecole e INIMITER, CNR, Milano
E. Licandro
Affiliation:
Dipartimento di Chimica Organica e Industriale, Universita' di Milano, Milano
S. Maiorana
Affiliation:
Dipartimento di Chimica Organica e Industriale, Universita' di Milano, Milano
A. Papagni
Affiliation:
Dipartimento di Chimica Organica e Industriale, Universita' di Milano, Milano
Get access

Abstract

We report on a spectroscopical study of a novel class of push-pull molecules containing a Chromium or Tungsten atom connected to an oligothiophene through a carbenic bond. The electronic coupling between the π electrons of the conjugated system and the π electrons of the transition metal has been monitored through absorption and Raman spectra.

This interaction between d and π electrons leads to a red shift of the thienylene π-π* absorption band and to the appearance of a new strong metal to ligand charge transfer band at lower energies. In this latter transition the electrical dipole reverses its direction upon photoexcitation from the ground to the first excited state, thus accounting for the enhanced non linear optical response of these molecules. Solvatochromic effect has been used to estimate the second order molecular hyperpolarizability.

Type
Research Article
Copyright
Copyright © Materials Research Society 1998

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Bosshard, Ch., Sutter, K., Pretre, Ph., Hulliger, J., Florshemeier, M., Kaatz, P. Gunter, e P. in Advances in nonlinear optics-Vol. 1. Organic nonlinear optical materials Gordon and Breach Publishers, 1995.Google Scholar
2. Yoshimura, T., App. Phys. Lett. 55, 534 (1989).Google Scholar
3. Long, N., Angew. Chem. Int. Ed. Engl. 34, 21 (1995).Google Scholar
4. Fischer, E.O. et al., Transition Metal Carbene Complexes, Seyferth, P. Ed., 1983.Google Scholar
5. Maiorana, S., Papagni, A., Licandro, E., Parsoons, A., Clay, K., Houbrechts, S. and Porzio, W. Gazz. Chim. It. 125, 377 (1995).Google Scholar
6. Louam, G., Buisson, J.P., Lefrant, S. Fichou, e D., J. Phys. Chem. 99, 11399 (1995).Google Scholar
7. Adams, D. M., Metal-Ligand and related vibrations, Edward Arnold Ltd., London, 1967.Google Scholar
8. Furukawa, Y., Akimoto, M. and Harada, I., Synth. Met. 18, 151 (1987).Google Scholar
9. Guggenheim, E.A., Trans.Faraday Soc. 45, 714 (1949).Google Scholar
10. Cheng, L., Tam, W., Stevenson, S. H., Meredith, G. R., Rikken, G. and Marder, S.R., J. Phys. Chem. 95, 10631 (1991).Google Scholar
11. Paley, M.S., Harris, J.M., Looser, H.,Baumert, J.C., Bjorklund, G.C., Jundt, D. and Twieg, R.J., J.Org. Chem. 54, 3374 (1989).Google Scholar
12. McRae, E.G., J. Phys. Chem. 61,562 (1957).Google Scholar