Solid-solid phase transitions in phenalkylammonium salts

Oort, Michiel J. M. Van; White, Mary Anne

doi:10.1016/0040-6031(89)87023-6

Cited by 4 publications

(4 citation statements)

References 30 publications

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“…The angle between the molecular axis and the C para -C ipso axis is estimated to be 25°. Rotation around the molecular axis was also found to affect the 2 H line shape of the -ND 3 Using a T 1Z relaxation experiment, the rotation angle of the C-2 H bond was determined to be approximately 72°. This experiment also showed that C 3 jumps of the ion around the molecular axis do indeed provide a reasonable description of this reorientational process.…”

Section: Discussionmentioning

confidence: 97%

“…Thus in solid II the alkyl chain of the phenpropylammonium ion undergoes large amplitude motion with a temperature dependent jump angle. The onset of this motion could trigger the solid III-solid II phase transition [3].…”

Section: Discussionmentioning

confidence: 99%

“…Recently the phase transitions in the phenethyl-and phenpropyl-ammonium halides have been identified using differential scanning calorimetry (DSC) [3]. Although reasonably accurate transition temperatures and enthalpy changes can be obtained from such measurements, it is difficult to deduce microscopic and/or dynamic information using DSC.…”

Section: Introductionmentioning

confidence: 99%

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Molecular Motion in Phenpropylammonium Chloride Studied by Deuterium NMR

Gruwel

Wasylishen

1992

Zeitschrift Für Naturforschung A

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Cation dynamics in phenpropylammonium chloride, C 6 H 5 (CH 2 ) 3 NH 3 Cr, were studied in three different solid phases by means of 2 H nmr. Both 2 H nmr line shapes and spin-lattice relaxation studies were performed on the ammonium head group, the adjacent methylene group and the phenyl-ring. In the low temperature phase, solid III, the -ND 3 group dynamics were dominated by C 3 jumps about the C-N axis. From the observed minima in T 1Z and T 1Q a quadrupole coupling constant of 165 ± 5 kHz was obtained. The 2 H nmr line shapes of the methylene group indicate that this group does not execute any large amplitude motion in the low temperature phase. In contrast, the phenyl ring deuterium nuclei give rise to line shapes characteristic of C 2 ring flips about the Cpara~C ipso aX * S "In the solid II phase the 2 H nmr line shapes of both the -ND ? and -CD 2 -groups are characterized by asymmetric Pake powder patterns. Since one of the principal components of the electric field gradient tensor remains temperature independent for both groups, it was concluded that these groups perform planar large-amplitude motions between two sites.Axially symmetric spectra were obtained for all three groups in the high temperature phase, solid I. The 2 H nmr line shapes indicate the presence of whole ion reorientation about a molecular axis. In addition, the -ND 3 groups perform C 3 jumps about the C-N axis and the -C 6 D 5 group display line shapes characteristic for rotational diffusion about the C para -C ipso axis.

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Section: Discussionmentioning

confidence: 97%

Section: Discussionmentioning

confidence: 99%

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Molecular Motion in Phenpropylammonium Chloride Studied by Deuterium NMR

Gruwel

Wasylishen

1992

Zeitschrift Für Naturforschung A

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“…There are many examples of the isoenthalpic phase transformations (which do not include chemical reactions) described in literature. [15,45] Observation of this isoenthalpic phase transformation, as well as the finding that the dissociation of 3 requires unusually high entropy of activation of 1064 J K -1 mol -1 , could be an indication that the phase in which the solid-state chemical reaction occurs could resemble to a sort of intermediate liquid. This tentative assumption is in line with the very recent already mentioned findings that the solid-solid transformation involves a quasi-liquid state as an intermediate between the starting and the product solid phases.…”

Section: Irreversible Dissociationsmentioning

confidence: 98%

Thermally‐Induced Reactions of Aromatic Crystalline Nitroso Compounds

et al. 2019

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Three types of organic solid‐state reactions, dimerizations, dissociations, and Z‐E isomerizations were investigated by using the transformations of aromatic C‐nitroso compounds in crystalline solids as a convenient molecular model. Here we propose a conceptual frame for solid‐state organic reaction mechanisms by examining activation parameters obtained from kinetic measurements under specific experimental conditions. The possibility of the appearance of a sort of short‐lived intermediate liquid phase that constitutes a critical condition for initiating chemical reaction in crystalline solids, similarly to the mechanism for the thermal solid‐state reactions proposed by Paul and Curtin is discussed. The analogy of the proposed concept with the recent hypothesis about the variable rigidity/softness of the reaction cavity in the enzyme reactions, and with the newest molecular dynamic simulation studies of solid phase transformations was considered.

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Polymorphism of phenethylammonium bromide: the effect of particle properties on the thermodynamics

Oort

Cotton

1993

Thermochimica Acta

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Solid-solid phase transitions in phenalkylammonium salts

Cited by 4 publications

References 30 publications

Molecular Motion in Phenpropylammonium Chloride Studied by Deuterium NMR

Molecular Motion in Phenpropylammonium Chloride Studied by Deuterium NMR

Thermally‐Induced Reactions of Aromatic Crystalline Nitroso Compounds

Polymorphism of phenethylammonium bromide: the effect of particle properties on the thermodynamics

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