title: Manipulation of an intramolecular NH...O hydrogen bond by photoswitching between stable E/Z isomers of the cinnamate framework.
abstract: Novel carboxylic acid derivatives were synthesized, which allowed switching of the intramolecular distance between amide group and carboxylic oxygen atoms using E to Z photoisomerization of the cinnamate framework. An intramolecular NH...O hydrogen bond was formed in the Z carboxylate compound not only in solution but also in the solid state. The pK(a) value of the carboxylic acid was lowered as a consequence of the E/Z photoisomerization.
authors.affiliation: Department of Macromolecular Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Matsuhira
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Taka-Aki
authors.initials: TA
authors.lastname: Okamura
authors.forename: Norikazu
authors.initials: N
authors.lastname: Ueyama
mesh_terms: D002934:Cinnamates / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D010777:Photochemistry; D013056:Spectrophotometry, Ultraviolet
chemical_list: D002934:Cinnamates; C029010:cinnamic acid