Détermination structurale à 213 K du monomère bis(phénylcarbamate) de hexadiyne-2,4 diyle-1,6, C20H16N2O4

Whuler, A.; Spinat, P.; Brouty, C.

doi:10.1107/s0108270184005357

Cited by 6 publications

(5 citation statements)

References 4 publications

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“…4.2 Å) are considerably larger than the optimal values for butadiyne topochemical polymerization (45° and 3.5 Å, respectively, Scheme ). Although the reasons for this alternating/non-alternating variation between 1g and 1i are unclear, ,, it is evident that the conformational flexibility of the dehydro[24]annulene framework is an important factor in providing the large diversity of packing motifs seen in this work.…”

Section: Resultsmentioning

confidence: 95%

Directing the Crystallization of Dehydro[24]annulenes into Supramolecular Nanotubular Scaffolds

et al. 2016

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The self-assembly of a series of dehydro[24]annulene derivatives into columnar stacks has been examined for its latent ability to form π-conjugated carbon-rich nanotubular structures through topochemical polymerizations. We have studied the parameters affecting self-assembly, including the nature of the substituent and crystallization conditions, using 10 different dehydro[24]annulene derivatives. In particular, hydrogen-bonding interactions through carbamate groups were found to be especially useful at directing the formation of nanotubular supramolecular assemblies. We have also evaluated the electronic coupling between neighboring dehydroannulene molecules within these supramolecular assemblies. Density functional calculations on the stacked supramolecular nanotube assemblies show that transfer integrals vary considerably between the three columnar assemblies, ranging from moderate to high (59-98 meV for the highest occupied molecular orbitals, 63-97 meV for the lowest unoccupied molecular orbitals), depending on the local molecular topology. In addition, the dehydro[24]annulene derivatives afforded distinct architectures in the crystal, including nanochannel arrays, sheets with solvent-filled pores, and lamellae. This work is an essential step toward a controlled formation of covalently linked carbon-rich nanostructures generated from molecular precursors with a latent diacetylene reactivity.

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Section: Resultsmentioning

confidence: 95%

Directing the Crystallization of Dehydro[24]annulenes into Supramolecular Nanotubular Scaffolds

et al. 2016

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“…El compuesto en estudio puede efectivamente polimerizar, vía un mecanismo topoquímico [13,14]. Esta propiedad probablemente se relaciona con la perdida de cristalinidad observada durante la recolección de datos de difracción, acompañada de un cambio de color, de lila a purpura, en un periodo de dos días, fenómenos característicos de una polimerización parcial en el estado sólido [15][16][17][18]. Sin embargo, el conjunto de datos colectados, completo en un 84% hasta la resolución de 0.91 A, fue suficiente para determinar la estructura molecular, aunque a un nivel de refinamiento de baja calidad.…”

Section: Resultados Y Discusiónunclassified

Estructura Molecular y Cristalina de un Derivado Diacetilénico: Octa-3,5-diino-1,8-diil-Bis( Octilcarbamato)

Chavarin¹,

Flouriot

2011

QUIMICAHOY

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La síntesis de un derivado diacetilénico de fórmula C26H44N2O4 se llevó a cabo por medio de una condensación de Glaser, y la caracterización estructural se realizó por difracción de rayos X en monocristal. El compuesto resultó dificil de cristalizar, y solamente un monocristal en forma de lámina con un espesor limitado a 40 m se obtuvo para medir datos. Al ser el poder de difracción débil, la resolución experimental se limitó a 0.91 A, y no fue posible obtener una esfera de difracción completa, debido a la descomposición de la muestra bajo irradiación, probablemente a consecuencia de una polimerización en el estado sólido. Tal comportamiento se había reportado anteriormente para otros derivados diacetilénicos cercanos. La molécula se ubica sobre un centro de inversión, con los sustituyentes n-octil en conformación extendida trans, generando un sistema molecular con una longitud mayor a 36 A. Los grupos uretano forman puentes de hidrógeno intermoleculares N-H ... O a lo largo del eje cristalográfico corto a. La estructura supramolecular resultante, basada en ciclos R22 (30), es bidimensional, y los planos supramoleculares se apilan a una corta distancia de 3.65 A, adecuada para la polimerización en el estado sólido.

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“…A search of crystallographic databases shows that, even if groups forming HBs are often considered to promote the optimal stacking of reactive DAs, the direction of chain propagation in polymerization is not always parallel to the hydrogen bonded chains. , In fact, single crystal elucidations of PDA with HBs parallel to the π-conjugated backbone are scarce. , Furthermore, if HBs are too strong and too close to the DA group, they may inhibit the polymerization. − As a consequence, spacers of various lengths are widely used to bring enough flexibility for the reactive monomers and to increase the solubility of the polymer, or to control the odd/even effect of the alkyl chain side groups . To the best of our knowledge, a clear SCXRD structure determination of a PDA with an HBs network as close (such as the one reported here with 14 membered rings) to the PDA backbone and that coincides with the polymerization direction has not been reported, since these kinds of systems involved DA monomers which are only partially reactive in the solid state. ,− However, noncovalent backbone rigidification strategies, as well as the development of novel HB-constrained conjugated polymers, ,− may have considerable impact on the optoelectronic properties, since it can induce “conformational control and enhanced planarity along a conjugated polymer” …”

Section: Single Crystal Structures Analysismentioning

confidence: 99%

Rapid Access to Polychlorodiacetylene Single Crystals through H-Bond Templating and Computations on Helical PDA Oligomers

Baillargeon

Robidas

Legault

et al. 2020

Crystal Growth & Design

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Until now, only two structures of polyhalogenodiacetylene (PXDA) have been reported in the literature: polydiiododiacetylene (PDIDA) and polydibromodiacetylene (PDBDA). Herein we report the first example of the synthesis and topochemical polymerization of chlorodiacetylene (ClDA) to afford the single crystal X-ray diffraction (SCXRD) structure determination of polychlorodiacetylene (PClDA). A unique Hbonded network was exploited to achieve polymerization. The latter is parallel and close to the conjugated backbone, which constitutes the first clear single crystal example of this kind of system. Comparative DFT computational studies between the torsional potential on a model oligoClDA with the parent nonhalogenated compound were also performed. Finally, the capacity of the H-bonded network to induce helicity in the PDA chains was evaluated using semiempirical tight-binding calculations. The present work should contribute to the understanding of the exceptional optoelectronic properties of PDA associated with the presence of delocalized p-electrons in their backbone, with multiple possible sensing applications and electronic device conception, among many other possibilities.

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Détermination structurale à 213 K du monomère bis(phénylcarbamate) de hexadiyne-2,4 diyle-1,6, C20H16N2O4

Cited by 6 publications

References 4 publications

Directing the Crystallization of Dehydro[24]annulenes into Supramolecular Nanotubular Scaffolds

Directing the Crystallization of Dehydro[24]annulenes into Supramolecular Nanotubular Scaffolds

Estructura Molecular y Cristalina de un Derivado Diacetilénico: Octa-3,5-diino-1,8-diil-Bis( Octilcarbamato)

Rapid Access to Polychlorodiacetylene Single Crystals through H-Bond Templating and Computations on Helical PDA Oligomers

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