title: Direct Visualization of the Two-step Nucleation Model by Fluorescence Color Changes during Evaporative Crystallization from Solution.
abstract: The two-step nucleation model for crystal nuclei formation explains several experimental and theoretical results better than the classical nucleation theory. We report here direct visualization of the two-step nucleation model for organic molecular crystallization. Evaporative crystallization from a solution of a dibenzoylmethane boron complex that displays mechanofluorochromism, a fluorescence color change induced by mechanical perturbation, was probed by fluorescence change. The dependence of fluorescence change on dispersion concentration of the complex in a polymer matrix was also investigated. We detected transitional emission from the amorphous cluster state prior to crystallization. This is the first demonstration of the two-step nucleation model based on fluorescence color changes.
authors.affiliation: Department of Chemistry, Institute of Education, Shinshu University, 6-ro Nishinagano, Nagano 380-8544, Japan.
authors.forename: Fuyuki
authors.initials: F
authors.lastname: Ito
authors.affiliation: Department of Chemistry, Institute of Education, Shinshu University, 6-ro Nishinagano, Nagano 380-8544, Japan.
authors.forename: Yukino
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: Department of Chemistry, Institute of Education, Shinshu University, 6-ro Nishinagano, Nagano 380-8544, Japan.
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Fujimori
authors.affiliation: Department of Chemistry, Institute of Education, Shinshu University, 6-ro Nishinagano, Nagano 380-8544, Japan.
authors.forename: Takehiro
authors.initials: T
authors.lastname: Sagawa
authors.affiliation: Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8603, Japan.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Hara
authors.affiliation: Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8603, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Seki
authors.affiliation: Université Paris 13, Sorbonne Paris Cité, Laboratoire CSPBAT, CNRS, (UMR 7244), 74 rue Marcel Cachin, F-93017 Bobigny, France.
authors.forename: Ryohei
authors.initials: R
authors.lastname: Yasukuni
authors.affiliation: Université Paris 13, Sorbonne Paris Cité, Laboratoire CSPBAT, CNRS, (UMR 7244), 74 rue Marcel Cachin, F-93017 Bobigny, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Lamy de la Chapelle