Étude comparée des mouvements de réorientation moléculaire de benzènes penta et hexasubstitués à l’état solide :

Balcou, Y.; Meinnel, J.

doi:10.1051/jcp/1966630114

Cited by 14 publications

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“…In the seventies, the structures of several other HSB were studied, all of them were found to be disordered [3][4][5][6] within the space group P2 1 /n. At the same time, two European groups have systematically studied HSB by proton nuclear magnetic resonance and dielectric susceptibility in the 70-320 K temperature range [6][7][8][9][10]. They established that what Kitaigorodski called the "rotational crystalline state" was widespread [11].…”

Section: Previous Work On Halogenomethylbenzenesmentioning

confidence: 99%

Competing stacking modes in crystals of trihalogeno-trimethyl-benzene: Theory meets experiment

Meinnel

Amar

Boucekkine

et al. 2019

Journal of Crystal Growth

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The special case of the stacking of trihalogeno mesitylene (TXM) molecules has been investigated. Below 300 K, these molecules lead to needle shaped crystals in a triclinic arrangement. Thanks to DFT computations and an empirical atom-atom interaction model this packing mode has been rationalized. Aggregates of TXM molecules differently packed have been considered, namely dimers and trimers of type A, the molecules being piled one over the other along the axis a, and dimers B and trimers B, the molecules lying in the same bc plane. From the computations, it appears that the stabilizing energy of formation of a dimer of two molecules piled along a is several times larger than the energy gain obtained from the formation of a dimer of two neighbors in the bc plane. It has also been found that the energy of formation of a trimer of type A is approximately twice the energy of formation of a dimer A, so that an additive rule occurs. These conclusions are in perfect agreement with the experimental observations of the shape of the crystals obtained by crystallization from a super-saturated solution of TXM in an organic solvent: long needles with TXM molecules stacked along the axis a have always been obtained and never thin plate-like crystals.

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Section: Previous Work On Halogenomethylbenzenesmentioning

confidence: 99%

Competing stacking modes in crystals of trihalogeno-trimethyl-benzene: Theory meets experiment

Meinnel

Amar

Boucekkine

et al. 2019

Journal of Crystal Growth

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Molecular Motions in a Molecular Crystal: Tetrachloro‐m‐Xylene

Ramos¹,

Sousa²,

Correia³

et al. 1996

Ber Bunsenges Phys Chem

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In the present work we report a study of the molecular relaxation processes in tetrachloro‐m‐xylene in the solid state. The techniques of dielectric relaxation spectroscopy and thermally stimulated discharge currents were used in order to identify and characterise the different relaxation processes and it was found that a solid rotator phase appears on heating at a temperature of ∼−125°C. It was also observed by thermally stimulated currents that a higher temperature relaxation occurs above ∼−15°C. The attribution, at the molecular level, of this relaxation is not straightforward and it was suggested that it probably corresponds to the onset of the self‐diffusional motions in the solid.

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Order-disorder, polymorphism, and phase transformation in halogenobenzenes

Weiß

1982

Journal of Molecular Structure

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Étude comparée des mouvements de réorientation moléculaire de benzènes penta et hexasubstitués à l’état solide :

Cited by 14 publications

References 0 publications

Competing stacking modes in crystals of trihalogeno-trimethyl-benzene: Theory meets experiment

Competing stacking modes in crystals of trihalogeno-trimethyl-benzene: Theory meets experiment

Molecular Motions in a Molecular Crystal: Tetrachloro‐m‐Xylene

Order-disorder, polymorphism, and phase transformation in halogenobenzenes

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