title: The role of alkyl substituents in deazaadenine-based diarylethene photoswitches.
abstract: Diarylethenes are an important class of reversible photoswitches and often claimed to require two alkyl substituents at the carbon atoms between which the bond is formed or broken in the electrocyclic rearrangement. Here we probe this claim by the synthesis and characterization of four pairs of deazaadenine-based diarylethene photoswitches with either one or two methyl groups at these positions. Depending on the substitution pattern, diarylethenes with one alkyl group can exhibit significant photochromism, but they generally show poor stability towards extended UV irradiation, low thermal stability, and decreased fatigue resistance. The results obtained provide an important direction for the design of new efficient DNA photoswitches for the application in bionanotechnology and synthetic biology.
authors.affiliation: Institut für Pharmazie und Molekulare Biotechnologie, Universität Heidelberg, 69120 Heidelberg, Germany.
authors.forename: Christopher
authors.initials: C
authors.lastname: Sarter
authors.affiliation: Institut für Pharmazie und Molekulare Biotechnologie, Universität Heidelberg, 69120 Heidelberg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Heimes
authors.affiliation: Institut für Pharmazie und Molekulare Biotechnologie, Universität Heidelberg, 69120 Heidelberg, Germany.
authors.forename: Andres
authors.initials: A
authors.lastname: Jäschke
keywords: diarylethene; electrocyclic rearrangement; nucleoside; photochromism; photoswitch