Possible influence of a low-lying “covalent” excited state on the absorption spectrum and photoisomerization of 11-cis retinal

✍ Scribed by Robert R. Birge; Klaus Schulten; Martin Karplus

• Publisher: Elsevier Science
• Year: 1975
• Tongue: English
• Weight: 487 KB
• Volume: 31
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(75)85062-7

✦ Synopsis

The anomalous temperature dependence of the absorption spectrum and photochemical isomerktion efficiency of 1 Isis rctind is snalyzcd in terms of an equilibrium mixture of distorted 12-s-cir; and distorted lZs-;rrrzs conformers with the latter increasingly populated at lower temperature and/or greater solvent polarity. inclusion of ti possible sing ly and doubly excited configurations in the PFP formalism predicts a conformationally variant Ievcl orderins in thnt BL: 12-s&s conformations have a lowest excited 'il B,"-like singlet state whereas the majority of the 12-s-:mrrr cotiorma- tions have a 1oyes.t excited "'Ag"-like singlet state.

and "covalent" type