Molecular dynamics of β-carotene in solution measured by subpicosecond transient optical Kerr effect

✍ Scribed by P. Foggi; R. Righini; R. Torre; V.F. Kamalov

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 652 KB
• Volume: 193
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(92)85677-3

✦ Synopsis

Optical anisotropy was created and detected in diluted solutions of all-trans p-carotene in n-dodecane by femtosecond pump and probe pulses. At low pump intensity the anisotropy is due to photoselection produced by one-photon absorption, and it decays with the lifetime (8 ps) of the lowest electronic excited state of p-carotene. At high pump intensity optical Kerr effect can be detected thanks to the amplification of the solute non-linear susceptibility due to the resonance of the probe beam with the first electronic transition of bcarotene.

Besides the instantaneous electronic response, two relaxation times (250 fs and 2 I5 ps) are observed and attributed to the dynamics of pcarotene molecules in the ground electronic state.