Exploring the conformational space of bridge-substituted dithienylcyclopentenes
Maic Fredersdorf1,2, Robert Göstl3,4, Andreas Kolmer1
1Clemens-Schöpf-Institut für Organische Chemie und Biochemie, Technische Universität Darmstadt, Alarich-Weiss-Strasse 4, 64287 Darmstadt (Germany).
Abstract:
Stimuli responsive compounds and materials are of high interest in synthetic chemistry and materials science, with light being the most intriguing stimulus due to the possibility to remote control the physicochemical properties of a molecule or a material. There is a constant quest to design photoswitches with improved switching efficiency and especially diarylethene-type switches promise photo cyclization quantum yields up to unity. However, only limited attention has been paid towards the influence of the solution conformation on the switching efficiency. Here, we describe a detailed NMR spectroscopic investigation on the conformational distribution of bridge-substituted dithienylcyclopentenes in solution. We could discriminate between several photoactive and photoinactive as well as two diastereomorphous conformations and show that the trends observed in the switching efficiency match the conformer populations obtained from state of the art NMR parameters in solution.
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