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Photoactive cyclophanes, I. Synthesis, photophysical and photochemical properties of cinnamophanes
Author(s) -
Greiving Helmut,
Hopf Henning,
Jones Peter G.,
Bubenitschek Peter,
Desvergne JeanPierre,
BouasLaurent Henri
Publication year - 1995
Publication title -
liebigs annalen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0947-3440
DOI - 10.1002/jlac.1995199511274
Subject(s) - chemistry , photochemistry , cycloaddition , singlet oxygen , quantum yield , singlet state , fluorescence , derivative (finance) , structural isomer , yield (engineering) , absorption (acoustics) , oxygen , stereochemistry , organic chemistry , excited state , catalysis , physics , materials science , financial economics , economics , metallurgy , acoustics , quantum mechanics , nuclear physics
In order to transfer the so‐called topochemical control established by Schmidt and coworkers to fluid solutions, the [2.2]paracyclophane framework was substituted with two acryloyl substituents, one on each of the two decks. The 4 products thus formed are termed cinnamophanes. The pseudo‐gem derivative, 1 , was shown to undergo a very efficient stereospecific [2 + 2] photocycloaddition to form 5 with the highest quantum yield (0.8) ever observed for such a reaction. Whereas 2, 3 and 4 , the regioisomers of 1 , undergo a trans‐cis photoisomerisation, compound 1 leads to the photocycloadduct as the sole photoproduct. This unusually fast cycloaddition reaction is not sensitive to oxygen and is largely unaffected by temperature variations. It is believed to be a singlet state reaction. The synthesis and a spectroscopic (absorption and fluorescence emission) study of 1–4 and 5 are described.