title: Trifluoromethyl groups in crystal design of 1,4-diphenyl-1,3-butadienes for topochemical [2 + 2] photodimerization.
abstract: [structure: see text] UV irradiation of the powdered crystalline sample of each of three (E,E)-1,4-di(trifluoromethyl-substituted)phenyl-1,3-butadienes (1-3) was found to yield a single [2 + 2] cycloaddition product in the solid state. Moreover, upon irradiation, the crystalline samples of two (E,E)-1,4-di(trifluoromethyl- and fluorine-substituted)phenyl-1,3-butadienes (4, 5) undergo a similar conversion to afford a [2 + 2] cycloaddition product, respectively. Our observations suggest that trifluoromethyl groups can be used to direct 1,4-diphenyl-1,3-butadiene molecules to form a parallel, offset-stacked orientation suitable for topochemical [2 + 2] cycloaddition.
authors.affiliation: Department of Chemistry, Murray State University, Murray, Kentucky 42071, USA. jin.liu@murraystate.edu
authors.forename: Jin
authors.initials: J
authors.lastname: Liu
authors.forename: Natalie L
authors.initials: NL
authors.lastname: Wendt
authors.forename: Kelly J
authors.initials: KJ
authors.lastname: Boarman