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Photodimerization Processes in Self‐Assembled Chiral Oligo( p ‐phenylenevinylene) Bolaamphiphiles
Author(s) -
George Subi J.,
de Greef Tom F. A.,
Bovee Ralf,
van Dongen Joost L. J.,
Schenning Albertus P. H. J.,
Meijer E. W.
Publication year - 2009
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.200900031
Subject(s) - chemistry , materials science , crystallography
Highly discriminating cycloaddition : An unexpected [2+2] cycloaddition in self‐assembled cation OPV‐monolayered vesicles is described. Remarkably, the photochemical reaction is chemo‐, regio‐, and stereoselective, which is most likely the result of the well‐controlled supramolecular organization of the OPV units in the monolayer.An oligo( p ‐phenylene vinylene) (OPV) amphiphile has been synthesized with a positively charged head group on one end and a hydrophilic ethyleneglycol wedge on the other. In water, this bolaamphiphile forms vesicles consisting of a monolayer in which the OPV surfactants are organized in a helical head‐to‐tail fashion. Mass spectrometry analysis and reversed‐phase high performance liquid chromatography (RP‐HPLC) reveals that because of the presence of two double bonds in the OPV units, photo‐induced [2+2] cycloaddition takes place resulting in polymerization of the surfactants. Performing RP‐HPLC allowed the OPV dimer to be isolated in a sufficient amount to perform a variety of one‐ and two‐dimensional NMR experiments. These experiments show a highly stereoselective photochemical cycloaddition process resulting in a regioselective head‐to‐tail dimerization with a stereoselective syn arrangement.