Ellis A B, Schreiner R, Ulkus R A
Proc Natl Acad Sci U S A. 1981 Jul;78(7):3993-7. doi: 10.1073/pnas.78.7.3993.
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.
研究表明，几种视网膜异构体在异辛烷溶液中与镧系β-二酮配合物三（6,6,7,8,8,8-七氟-2,2-二甲基-3,5-辛二酮基）铕（III）[Eu（fod）3]形成加合物。这些加合物的特征是有一个吸收带，其在约420nm处的最大波长（λmax）相对于游离视网膜异构体中最低能量吸收带红移了约60nm。照射该加合物带会导致光异构化。例如，在514.5nm处对1mM全反式视网膜/3mMEu（fod）3异辛烷溶液进行光解，以合理的量子效率（φ≥0.05）产生的异构体混合物与在没有Eu（fod）3的情况下用紫外线激发产生的异构体混合物有很大不同。在非极性溶剂中进行光解时特别值得注意的是，加合物光解产物中存在相当数量的11-顺式视网膜。
