Single-Crystal-to-Single-Crystal Transformation of Diolefin Derivatives in Nanocrystals

Abstract

Topochemical [2 + 2] cycloaddition polymerization of methyl p-phenylenediacrylate and 2,5-distyrylpyridine in nanocrystals, prepared by the reprecipitation method, were investigated in comparison with those in bulk crystals. The bulk single crystals, larger than 1 mum in size, broke into microcrystals with variety of size and shape in the course of polymerization. Interestingly, however, these nanocrystals show single-crystal-to-single-crystal transformation.

Hybridized Organic Nanocrystals for Optically Functional Materials

“…PDA is one of the most promising organic nonlinear optical (NLO) materials, 63 which means large third-order NLO susceptibility » (3) (½) with very fast optical response. 6466 Organic NCs have been also investigated in detail after developing the reprecipitation methods: i.e., nanocrystallization processes to further control crystal size and shape 42,67,68 the size dependence of linear optical properties and reactivity in solid-state polymerization, 23,49,50,52,69 the enhanced NLO properties in layered thin films of PDA NCs prepared by layer-by-layer technique, 23,7072 and applied electric-or magnetic-field-induced orientation of "liquid and crystal" systems consisting of DAST NCs dispersion liquids. 51,7375 It goes without saying that more creative research fields concerning highly optical functional organic NCs, that is to say, "New Creation of Hybridized Organic NCs," 7685 should be advanced intensively toward next-generation organic optoelectronic and photonic device applications.…”

Functional Organic Nanocrystals

“…A -conjugate polymer, polydiacetylene (PDA), is one of the promising compounds having high carrier mobility. PDA is a unique material, which combine the properties of an essentially one-dimensional, fully conjugated polymer with the ability of single crystalline monomers to polymerize without disruption of the crystallinity (Takahashi, et al, 2002). PDA has the optical properties of large non-linear optical susceptibility and ultra-fast response time as well as a PDA been predicted to present very high charge carrier mobility, up to 10 3 -10 5 cm 2 /V s. However the real mobility of PDA crystals measured using time-of-flight technique was found to be 1-10 cm 2 /V s, and that is comparable to those measured on polyacene molecular crystals such as anthracene or naphthalene.…”

“…Nanoparticles were prepared from -carotene and observed the influence of both supramolecular structure and particle size on the absorption spectra. The size dependence of the luminescence and the enhanced emission of the nanoparticles prepared with this method were studied in Yao's group (Fu & Yao, 2001) and Park's group (An, et al, 2002). One of the interesting feature occurred in nanocrystals, recently Park' group reported a phenomenon named aggregation induced enhanced emission (AIEE).…”

Molekülkristalle in Bewegung: von topotaktischen Photoreaktionen zu molekularen Maschinen

“…Aus der Volumen-und Konzentrationsabhängigkeit der Stufenbildung an der Oberfläche von 1 c sowie aus den Ergebnissen kürzlicher Studien, die darauf hindeuten, dass topotaktische Reaktionen am ehesten bei nanokristallinen Kristallexemplaren auftreten, [14,15] …”