Domino-like thermal phase transition of 2,3-bis(phenylethenyl)-5,6-dicyanopyrazine crystal

Ahn, Kwang–Soon; Lee, Do Kyung; Kim, Jae Hong; Kim, Sung Hoon

doi:10.1016/j.dyepig.2010.08.016

Cited by 9 publications

(6 citation statements)

References 18 publications

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“…[1][2][3] The present study is concerned with the design, synthesis and characterisation of dicyanopyrazine-related heterocycles. [4][5][6] Specifically, the solubility of a cyanoheterocyclic compound has been improved by the introduction of a t-butylphenyl unit. The spectral properties of these compounds are affected by molecular aggregation and their functionalities are correlated with their chemical structures.…”

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confidence: 99%

Synthesis and Spectral Characterisation of Dicyanopyrazine-related Cyanoheterocycles

Song

Jang

Wang

et al. 2013

Journal of Chemical Research

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Four dicyanopyrazine-related cyanoheterocycles have been synthesised and characterised; they show different absorption maxima values and molar absorptivity in absorption spectra. HOMO and LUMO energy levels have been obtained by electrochemical measurements and DMol3 calculation and show little difference in HOMO values but big differences in LUMO values. Their UV-Vis absorbance and fluorescence spectra have been investigated in chloroform and toluene and their aggregation decreases as the concentration decreases in toluene.

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confidence: 99%

Synthesis and Spectral Characterisation of Dicyanopyrazine-related Cyanoheterocycles

Song

Jang

Wang

et al. 2013

Journal of Chemical Research

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“…S4 ). The G-form showed a very small but clear endothermic peak at 178.6 °C, due to a crystal-to-crystal transition of lattice contraction in addition to a sharp endothermic peak at 253.3 °C due to melting, while the O-form showed only a sharp endothermic peak at 258.2 °C 24 . As shown in Fig.…”

Section: Resultsmentioning

confidence: 97%

“…These 1 H-NMR spectra indicate that the O- and G-crystals have same chemical structure in isolated solution state, even though they exhibit different FL emission spectra in solid state. This resulted from the polymorphism of DSP, which is induced by a slight difference (~ 0.11 Å) in the interlayer c -axis distance between two crystals 23 , 24 . Since the O- and G-form have same crystal structure (monoclinic) and lattice parameters except for slight difference in the interlayer c -axis distance, therefore, it is expected that diffraction peaks in O-form will be similar as those of G-form in the XRD experiment.…”

Section: Resultsmentioning

confidence: 99%

“…In this study, we report a unique PCFL-active metachromatic material, which recover its original FL emission by UV irradiation unlike the restoration of original color by thermal annealing or recrystallization. Recently, Kim, one among the authors, synthesized a polymorphic crystal compound of 2,3-diisocyano-5,6-distyrylpyrazine (DSP in Scheme 1 ) 23 , 24 . This compound exhibited two different types of crystal morphology.…”

Section: Introductionmentioning

confidence: 99%

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Unusual piezochromic fluorescence of a distyrylpyrazine derivative crystals: phase transition through [2 + 2] photocycloaddition under UV irradiation

Jin

Park

Moon

et al. 2021

Sci Rep

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The piezochromic fluorescence (FL) of a distyrylpyrazine derivative, 2,3-diisocyano-5,6-distyrylpyrazine (DSP), was investigated in this study. Depending on the recrystallization method, DSP afforded two different crystals with green and orange FL emission. The orange color FL emission crystal (O-form) was easily converted to the green color FL emission one (G-form) by manual grinding. The G-form was also converted to a slightly different orange color FL emission crystal (RO-form) by a weak UV irradiation. When the RO-form was ground again, the G-form was regenerated. The FL colors changed between the G- and RO-forms over several ten times by repeated mechanical grinding and UV irradiation. The FL, UV–visible, 1H-NMR and XRD results showed that the O (or RO)-to-G transformation induced by mechanical stress results from the change of degree of molecular stacking from dense molecular stacking structure to relatively loose molecular stacking structure, whereas the G-to-RO reconversion by UV irradiation results from return to dense molecular stacking structure again due to lattice movement (lattice slipping) allowed by photocycloaddition in solid-state.

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“…The transformation began at a single starting point in the yellow crystal and then spread out into the whole crystal like a domino at 174.5°C. [18] We expected that phase transition of organic crystals in small size, i.e. in nanoparticles, can occur much easily.…”

Section: Introductionmentioning

confidence: 99%

Preparation of nanoparticles of a violanthrone derivative with properties of J-like aggregates

Masaki

Kasatani

Morita

2012

Trans. Mat. Res. Soc. Japan

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Organic nanoparticles of violanthrone 78, a violanthrone derivative, were prepared by a reprecipitation method. The nanoparticles were annealed at 60°C and the nanoparticles were changed to J-aggregates. UV/visible spectra, fluorescence spectra, and fluorescence lifetimes of the nanoparticles prepared were measured. UV/visible spectra shows that the wavelength of main absorption band shifted from 610 nm to 630 nm after annealing, and the absorbance of the band increased by more than twice, and sharpening of the main band was also observed. Nanoparticles without annealing were not fluorescent. After annealing, fluorescence of the nanoparticles with a small Stokes shift was observed at 650 nm. From these results, it was suggested that the J-aggregates phase transition occurred by annealing. Fluorescence lifetime of the annealed nanoparticles was as short as 20 ps.

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Domino-like thermal phase transition of 2,3-bis(phenylethenyl)-5,6-dicyanopyrazine crystal

Cited by 9 publications

References 18 publications

Synthesis and Spectral Characterisation of Dicyanopyrazine-related Cyanoheterocycles

Synthesis and Spectral Characterisation of Dicyanopyrazine-related Cyanoheterocycles

Unusual piezochromic fluorescence of a distyrylpyrazine derivative crystals: phase transition through [2 + 2] photocycloaddition under UV irradiation

Preparation of nanoparticles of a violanthrone derivative with properties of J-like aggregates

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