title: Heterocyclic quinol-type fluorophores: synthesis, X-ray crystal structures, and solid-state photophysical properties of novel 5-hydroxy-5-substituent-benzo[b]naphtho[1,2-d]furan-6-one and 3-hydroxy-3-substituent-benzo[kl]xanthen-2-one derivatives.
abstract: Novel heterocyclic quinol-type fluorophores (4 a-c) and (5 a-c) that contain substituents (R = Me, Bu, Ph) with nonconjugated linkages to the chromophore skeleton have been synthesized and their photophysical properties have been investigated in solution and in the solid state. Considerable differences in the absorption and fluorescence spectra were observed between the two states. Quinols 4 a-c and 5 a-c exhibited almost the same absorption and fluorescence spectra in solution; however, their solid-state fluorescence excitation and emission spectra in the crystalline state were quite different. We performed X-ray crystallographic analyses to elucidate the dramatic effect of the substituents of the nonconjugated linkage on the solid-state fluorescence excitation and emission spectra. The relationships between the solid-state photophysical properties and the chemical and crystal structures of 4 a-c and 5 a-c are discussed on the basis of the X-ray crystal structures.
authors.affiliation: Department of Material Science, Faculty of Science Kochi University, Kochi 780-8520, Japan.
authors.forename: Yousuke
authors.initials: Y
authors.lastname: Ooyama
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Okamoto
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Suzuki
authors.forename: Akiko
authors.initials: A
authors.lastname: Hayashi
authors.forename: Katsuhira
authors.initials: K
authors.lastname: Yoshida