A study of isomeric retinal triplets by low temperature spectroscopic and kinetic flash photolysis

✍ Scribed by Maciej Grodowski; R.S.H. Liu; William G. Herkstroeter

• Publisher: Elsevier Science
• Year: 1979
• Tongue: English
• Weight: 338 KB
• Volume: 65
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(79)80121-9

✦ Synopsis

Re.zeiucd 24 Aprit 1979; in find furm 29 \Ia)-t979 SpectrtiscopicanlI kineticdata of tripietr of al[-trzms retinal and _w\erat of the cis isomers obtained with frozen samples =t IiquilI nitrogen rcmperature arc reported-They are betiewd due to unisomerized triplets of the corresponding ground state isomers_ intcrcstin$~, der=y of transients from 7-ckretinal xas found to be waelen@h dependent. Since the early work of Livingston et al_ [2 j and Abrikmson et al_ 133 on absorption and decay properties of triplets from ali-trans retina!, many papers on the subject have appeared including several on other geomet,sic isomers I4-6]_ However, all the work reported so far was carried our in fluid solution at room temperrtture, n condition that is bound to 1-d to some f2SteIii of isomerir3tion The matter is further complicated by the fact that the trzmsients derived horn different isomers of retinal show simiIar absorption and decay properties [q--61 _ Therefore, there is ahvays the atsing Joubt whether the tnnsient absorption spectra recorded from isomerically pure retinaIs correspond to those of the original isomers, or are actually contamipzted with signifknt mnounts of the isomedzed trip-Iets [6J _ We have now carried out a study of triplets of &f&rent isomers of retinal at liquid nitrogen temperature in frozen media, P condition that is less IikeIy to Iead to geometric isomerizatiotx Part of the rest&s is reported here_ During the course of this study two additiona: papea on hscr flash photofq'sis studies of retina1 isomers appwred In rhe iirerarurc, descrbing absorption properties of transients immediately after flash excitation * Photochemistry of polenes t.5 For no_ 13 see ref. [ 1 I_