title: Structural properties of a series of photochromic fluorinated indolylfulgides.
abstract: Fluorinated indolylfulgides are a class of photochromic organic compounds that meet many of the requirements for use as optical memory media and optical switches. The X-ray crystal structures of a series of five photochromic fluorinated indolylfulgides have been determined, namely (3Z)-3-[1-(1,2-dimethyl-1H-indol-3-yl)-2,2,2-trifluoroethylidene]-4-(1-methylethylidene)dihydrofuran-2,5-dione (trifluoromethylisopropylideneindolylfulgide), C(19)H(16)F(3)NO(3), (I), (3Z)-3-[1-(1,2-dimethyl-1H-indol-3-yl)-2,2,3,3,3-pentafluoropropylidene]-4-(1-methylethylidene)dihydrofuran-2,5-dione (pentafluoroethylisopropylideneindolylfulgide), C(20)H(16)F(5)NO(3), (II), (3Z)-3-[1-(1,2-dimethyl-1H-indol-3-yl)-2,2,3,3,4,4,4-heptafluorobutylidene]-4-(1-methylethylidene)dihydrofuran-2,5-dione (heptafluoropropylisopropylideneindolylfulgide), C(21)H(16)F(7)NO(3), (III), (3Z)-3-[1-(1,2-dimethyl-1H-indol-3-yl)-2,2,2-trifluoroethylidene]-4-(tricyclo[3.3.1.1(3,7)]decylidene)dihydrofuran-2,5-dione (trifluoromethyladamantylideneindolylfulgide), C(26)H(24)F(3)NO(3), (IV), and (3Z)-3-[1-(1,2-dimethyl-1H-indol-3-yl)-2,2,3,3,4,4,4-heptafluorobutylidene]-4-(tricyclo[3.3.1.1(3,7)]decylidene)dihydrofuran-2,5-dione (heptafluoropropyladamantylideneindolylfulgide), C(28)H(24)F(7)NO(3), (V). The photochromic property of fulgides is based on the photochemically allowed electrocyclic ring closure of a hexatriene system to form a cyclohexadiene. For each fulgide examined, the bond lengths within the hexatriene system alternate between short and long, as expected. Comparing the structures of the five fulgides with each other demonstrates no significant difference in bond lengths, bond angles or dihedral angles within the hexatriene systems. The distance between the bond-forming C atoms at each end of the hexatriene system does vary. Correlations of structural properties with optical properties are addressed.
authors.affiliation: Department of Chemistry and W. M. Keck Center for Molecular Electronics, Syracuse University, Syracuse, NY 13244, USA.
authors.forename: Mason A
authors.initials: MA
authors.lastname: Wolak
authors.forename: Robert C
authors.initials: RC
authors.lastname: Finn
authors.forename: Randy S
authors.initials: RS
authors.lastname: Rarig
authors.forename: Craig J
authors.initials: CJ
authors.lastname: Thomas
authors.forename: Robert P
authors.initials: RP
authors.lastname: Hammond
authors.forename: Robert R
authors.initials: RR
authors.lastname: Birge
authors.forename: Jon
authors.initials: J
authors.lastname: Zubieta
authors.forename: Watson J
authors.initials: WJ
authors.lastname: Lees
mesh_terms: D000218:Adamantane / Q000737:chemistry*; D000475:Alkenes / Q000737:chemistry*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D017611:Fluorine Compounds / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry*; D008027:Light; D008958:Models, Molecular; D015394:Molecular Structure; D010777:Photochemistry
chemical_list: D000475:Alkenes; D017611:Fluorine Compounds; D007211:Indoles; C020855:adamantylidene; C013658:propylene; D000218:Adamantane