Open AccessMediation of retinal photoisomerization by adduct formation with tris(6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionato)-europium(II).
Author(s) -
Arthur B. Ellis,
Rodney Schreiner,
Richard A. Ulkus
Publication year - 1981
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.78.7.3993
Subject(s) - photoisomerization , adduct , chemistry , photochemistry , europium , photodissociation , solvent , absorption band , absorption (acoustics) , retinal , isomerization , organic chemistry , materials science , optics , catalysis , ion , physics , composite material , biochemistry
Several retinal isomers are shown to form adducts in isooctane solution with a lanthanide beta-diketonate complex, tris(6,6,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionato)europium(III) [Eu(fod)3]. The adducts are characterized by an absorption band whose lambda max at approximately 420 nm is red-shifted by approximately 60 nm from the lowest-energy absorption band in the free retinal isomers. Irradiation into this adduct band leads to photoisomerization. For example, photolysis of a 1 mM all-trans-retinal/3 mM Eu(fod)3 isooctane solution at 514.5 nm leads, with reasonable quantum efficiency (phi greater than or equal to 0.05), to isomeric mixtures that are considerably different from these produced with UV excitation in the absence of Eu(fod)3. Particularly noteworthy for a photolysis conducted in a nonpolar solvent is the presence of an appreciable quantity of 11-cis-retinal in the adduct photolysate.