title: Comparative Evaluation of Substituent Effect on the Photochromic Properties of Spiropyrans and Spirooxazines.
abstract: Spiropyrans and spirooxazines represent an important class of photochromic compounds with a wide variety of applications. In order to effectively utilize and design these photoswitches it is desirable to understand how the substituents affect photochromic properties, and how the different structural motifs compare under identical conditions. In this work a small library of photoswitches was synthesized in order to comparatively evaluate the effect of substituent modifications and structure on photochromism. The library was designed to modify positions that were believed to have the greatest effect on C-O bond lability and therefore the photochromic properties. Herein we report a comparative analysis of the UV and visible light responses of 30 spiropyrans, spiroindolinonaphthopyrans, and spirooxazines. The influence of gadolinium(III) binding was also investigated on the library of compounds to determine its effect on photoswitching. Both assays demonstrated different trends in substituent and structural requirements for optimal photochromism.
authors.affiliation: Department of Chemistry, University of California at Davis , One Shields Avenue, Davis, California 95616, United States.
authors.forename: Edward I
authors.initials: EI
authors.lastname: Balmond
authors.affiliation: Department of Chemistry, University of California at Davis , One Shields Avenue, Davis, California 95616, United States.
authors.forename: Brandon K
authors.initials: BK
authors.lastname: Tautges
authors.affiliation: Department of Chemistry, University of California at Davis , One Shields Avenue, Davis, California 95616, United States.
authors.forename: Andrea L
authors.initials: AL
authors.lastname: Faulkner
authors.affiliation: Department of Chemistry, University of California at Davis , One Shields Avenue, Davis, California 95616, United States.
authors.forename: Victor W
authors.initials: VW
authors.lastname: Or
authors.affiliation: Department of Chemistry, University of California at Davis , One Shields Avenue, Davis, California 95616, United States.
authors.forename: Blanka M
authors.initials: BM
authors.lastname: Hodur
authors.affiliation: Department of Chemistry, University of California at Davis , One Shields Avenue, Davis, California 95616, United States.
authors.forename: Jared T
authors.initials: JT
authors.lastname: Shaw
authors.affiliation: Department of Biomedical Engineering and Chemistry Graduate Group, University of California at Davis , One Shields Avenue, Davis, California 95616, United States.
authors.forename: Angelique Y
authors.initials: AY
authors.lastname: Louie