183. The crystalline structure of the sugars. Part IV. Pentaerythritol and the hydroxyl bond

Llewellyn, F. J.; Cox, Ε. G.; Goodwin, T. H.

doi:10.1039/jr9370000883

Cited by 54 publications

(22 citation statements)

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“…Crystal structure analysis with X-ray (LLEWELLYN et al;NITTA, WATANABE 1937;SHIONO et al;LADD;EILERMAN, RUDMAN) and neutron scattering (HVOSLEF) did not contradict the assumption, that there is a molecular arrangement in the space group 13. The latest papers date from 1979.…”

Section: Pentaerythritementioning

confidence: 75%

Twinning of crystals as a result of differences between symmetrical and energetical most favourable structure arrangements

Krafczyk¹,

Jacobi²,

Follner³

1994

Cryst. Res. Technol.

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It is thought that the building units of crystal structures always tend to the highest possible symmetrical arrangements. These arrangements have not to correspond in every case to the energetical most favourable structure. Structures that show this distinct misfit tend to twinning. The examination of pentaerythrite and 1,2,4,5-tetrabromobenzene, two substances usually existing as twins, leads to the finding of structures -by lattice-energy calculations -with a better energy balance, but are not known yet as autonomous phases. Both cases showed arrangements with lower symmetry explaining the transition between the twin individuals. Following this theory the development of crystal twins is based on a structural instability caused by the conflict between the more favourable energetical arrangement and the highest available symmetry.Es wird davon ausgegangen, daR die Bausteine in den Kristahtrukturen stets eine hochstmogliche symmetrische Anordnung anstreben. Diese Anordnung muR nicht immer mit der energetisch gunstigsten Struktur iibereinstimmen. Strukturen, bei denen diese Diskrepanz ausgeprdgt ist, neigen zur Verzwillingung. Anhand von Pentaerythrit und 1,2,4,5-Tetrabrombenzol, die praktisch nur als Zwillinge bekannt sind, wurden durch Gitterenergieberechnungen Strukturen gefunden, die energetisch gunstiger sind, aber als eigenstandige Phasen bisher nicht bekannt sind. In beiden Fallen ergaben sich Anordnungcn geringerer Symmetrie. Mit Hilfe dieser Strukturen ist der Ubergang zwischen den Zwillingsindividuen erkllrbar. Nach dieser Theorie beruht die Bildung von Kristallzwillingen auf struktureller Instabilitat hervorgerufen durch den Konflikt zwischen energetisch giinstigster Anordnung und hochstmoglicher Symmetrie.

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Section: Pentaerythritementioning

confidence: 75%

Twinning of crystals as a result of differences between symmetrical and energetical most favourable structure arrangements

Krafczyk¹,

Jacobi²,

Follner³

1994

Cryst. Res. Technol.

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“…The symmetry of pentaerythritol has been a point of discussion for a long time, but was established as being tetragonal with space group I4 by Llewellyn, Cox & Goodwin (1937). The external symmetry of the crystals suggests the existence of a fourfold rotation axis, which is, however, not compatible with the internal structure.…”

Section: Introductionmentioning

confidence: 99%

“…The atomic positions were derived by, among others, Llewellyn, Cox & Goodwin (1937) and Shiono, Cruickshank & Cox (1958) from X-ray measurements, while Hvoslef (1958) has performed a neutron-diffraction study. The central carbon atoms are situated at the corners and in the centre of the tetragonal unit cell (Fig.…”

Section: Introductionmentioning

confidence: 99%

Structural investigation of hydrogen bonds in deuterated pentaerythritol by nuclear magnetic resonance

Lugt¹,

Smit²,

Perdok³

1968

Acta Cryst Sect A

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“…The structure of the low-temperature ordered form of PE (body-centered tetragonal, /4 with Z = 2) has been the subject of many reports (Llewellyn, Cox & Goodwin, 1937;Hvoslef, 1958;Eilerman & Rudman, 1979;Ladd, 1979;Semmingsen, 1988). This form is stable up to T~ = 460.7 (10) K (Barrio et al, 1990).…”

Section: Introductionmentioning

confidence: 99%

Thermal-expansion tensors of pentaerythritol (PE) and pentaglycerin (PG) and compositional deformation tensor of PG1−xPEx molecular alloys

Font¹,

López²,

Muntasell³

et al. 1994

J Appl Cryst

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The anisotropy of the molecular interactions in the low-temperature phase (body-centered tetragonal) of pentaerythritol [PE, 2,2-bis(hydroxymethyl)-1,3-propanediol, C(CH2OH), ] and pentaglycerin [PG, 2-hydroxymethyl-2-methyl-1,3-propanediol, (CH3)C(CH2OH)3 ] has been made evident by means of the thermal-expansion tensor calculated from room temperature to 433 K for PE and from room temperature to 353 K for PG. The weakest expansion has been found in the (00/) planes, where the molecules are linked by hydrogen bonds; the strongest has been found in the [001] direction, where van der Waals interactions play a dominant part. In addition, the compositional deformation tensor as a function of the composition in PGI_xPEx molecular alloys has been calculated at two temperatures (293 and 348 K). On the basis of the structural characteristics of the constituent pure substances, the directions of the strongest and weakest deformations -compression in the [001] direction and expansion in the (00/) planes, respectively -have been explained in terms of the substitution of PE guest molecules in the PG host structure.

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183. The crystalline structure of the sugars. Part IV. Pentaerythritol and the hydroxyl bond

Cited by 54 publications

References 0 publications

Twinning of crystals as a result of differences between symmetrical and energetical most favourable structure arrangements

Twinning of crystals as a result of differences between symmetrical and energetical most favourable structure arrangements

Structural investigation of hydrogen bonds in deuterated pentaerythritol by nuclear magnetic resonance

Thermal-expansion tensors of pentaerythritol (PE) and pentaglycerin (PG) and compositional deformation tensor of PG1−xPEx molecular alloys

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