A flash photolysis study of all-trans-retinal in langmuir-blodgett films and in liposomes

✍ Scribed by Marjo Ikonen; Helge Lemmetyinen; Aleksander Alekseev; B.I. Mitsner; Valery Savransky; Aleksander Prokhorov

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 418 KB
• Volume: 164
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(89)85009-2

✦ Synopsis

The triplet-triplet absorption decay and changes in the ground-state absorption spectra of all-trans-retinal (ATR) has been studied in Langmuir-Blodgett films (LB films), in liposomes and in hexane solution. In addition all-trans.retinal acid (ATRA) has been studied in LB films and in hexane. In LB films the decay of the triplet absorption of ATR is bi-exponential. When the number of excitation pulses increases, the relative fraction of one decay component decreases and the decay of the triplet state changes to mono-exponential. In liposomes and hexane the decay of the triplet state is independent of the number of excitation pulses and 1s bi-exponential for liposomes but mono-exponential in hexane solution. The changes are due to a photopolymerization reaction via the triplet state. For ATR the polymerization can also take place by thermal processes. The triplet absorption of ATRA cannot be observed in LB films or in hexane. but the polymerization takes place in LB films under the influence of light.