The crystal structure of deuterated benzene

Jeffrey, G. A.; Ruble, J. R.; McMullan, R. K.; Pople, John A.

doi:10.1098/rspa.1987.0132

Cited by 155 publications

(91 citation statements)

References 9 publications

(6 reference statements)

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“…A comparison of selected gij(r)s of the EPSR model of the benzene-methanol azeotrope with characteristic distances of the pure crystals 63,64 and pure liquid methanol 37 are given in Figure 5(a). In contrast to acetone-chloroform, the gij(r)s of the benzene-methanol azeotrope indicate that the strength of the interactions between the components is substantially more unbalanced.…”

Section: Local Structure Of the Benzene-methanol Azeotropementioning

confidence: 99%

“…Consistent with similar data presented for pure methanol, 37 the OM atoms of neighbouring molecules are most likely found along the direction of the OM-H1M bond, when the central molecule acts as a hydrogen bond donor, as well as below the OM atom of the central molecule as it accepts hydrogen bonds from neighbouring molecules. 65 , pure crystalline benzene (magenta), 64 and liquid methanol (blue). 37 (b) OM-OM tij(r) separated into contributions from 1 st , 2 nd , 3 rd and 4 th closest neighbours using the ANGULA software.…”

Section: Local Structure Of the Benzene-methanol Azeotropementioning

confidence: 99%

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Microstructures of negative and positive azeotropes

Shephard

Callear

Imberti

et al. 2016

Phys. Chem. Chem. Phys.

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The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Azeotropes famously impose fundamental restrictions on distillation processes, yet their special thermodynamic properties make them highly desirable for a diverse range of industrial and technological applications. Using neutron diffraction, we investigate the structures of two prototypical azeotropes, the negative acetone-chloroform and the positive benzenemethanol azeotrope. C-H···O hydrogen bonding is the dominating interaction in the negative azeotrope but C-Cl···O halogen bonding contributes as well. Hydrogen-bonded chains of methanol molecules, which are on average longer than in pure methanol, are the defining structural feature of the positive azeotrope illustrating the fundamentally different local mixing in the two kinds of azeotropes. The emerging trend for both azeotropes is that the more volatile components experience the more pronounced structural changes in their local environments as the azeotropes form. The mixing of the acetonechloroform azeotrope is essentially random above 20 Å where the running Kirkwood-Buff integrals of our structural model converge closely to the ones expected from thermodynamic data. The benzene-methanol azeotrope on the other hand displays extended methanol-rich regions and consequently, the running Kirkwood-Buff integrals oscillate up to at least 60 Å. Our study provides first insights into the microstructures of azeotropes and a direct link with their thermodynamic properties. Ultimately, this will provide a route for creating tailored molecular environments in azeotropes to improve and fine-tune their performances.

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Section: Local Structure Of the Benzene-methanol Azeotropementioning

confidence: 99%

Section: Local Structure Of the Benzene-methanol Azeotropementioning

confidence: 99%

Microstructures of negative and positive azeotropes

Shephard

Callear

Imberti

et al. 2016

Phys. Chem. Chem. Phys.

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“…35 The crystal structures chosen for the compounds studied are derived from x-ray and neutron diffraction experiments at various temperatures. The structures derived from neutron diffraction data are acetylene at a temperature of 110 K, 36 urea at 123 K, 32 and benzene at 123 K, 37 and the structure of 2-methyl-4-nitroaniline ͑MNA͒ is taken from the data measured at 100 K, the details of which will be reported in a forthcoming publication. 38 The 90 K structure of formamide 39 and the 23 K structure of glycine 40 have been taken from the charge density analysis of accurate x-ray diffraction data, and the structure of hydrogen cyanide at 180 K was taken from the unpublished x-ray diffraction data, as described by Platts and Howard.…”

Section: Examples and Conclusionmentioning

confidence: 99%

Dipole and quadrupole moments of molecules in crystals: A novel approach based on integration over Hirshfeld surfaces

Whitten

Radford

McKinnon

et al. 2006

The Journal of Chemical Physics

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Interaction-induced dipoles of hydrogen molecules colliding with helium atoms: A new ab initio dipole surface for high-temperature applications J. Chem. Phys. 136, 044320 (2012) Elegant expressions are derived for the computation of dipole and quadrupole moments of molecules using the electrostatic potential and electric field evaluated on an oriented molecular surface. These expressions are implemented for Hirshfeld surfaces, applied to various molecular crystals, and compared with the results from the quantum theory of atoms in molecules. The effect of intermolecular interactions is also explored by examining the differences between electrostatic moments derived from a periodic Hartree-Fock electron density and an electron density resulting from a superposition of noninteracting molecules. The enhancement of the dipole moment for hydrogen bonded molecular crystals is typically 30%-40% and shown to be largely independent of the partitioning scheme. Dipole moments calculated from Hirshfeld surfaces systematically underestimate those from zero-flux surfaces, a result attributed to the translation of the Hirshfeld surface relative to the zero-flux surfaces for these molecules. For acetylene and benzene, the differences between a crystal calculation and the sum of noninteracting molecules are small, and both partitioning schemes yield quadrupole and second moment results in close agreement.

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“…l.ti, #,j, Oij, V E,, Stewart & Jensen (1967) Kvick & Popelier (1992); (e) Jeffrey, Ruble, McMullan & Pople (1987); (f) Coppens (1967); (g) Jeffrey, Ruble, McMullan, DeFrees, Binkley & Pople (1980); (h) Savariault & Lehmann (1980); (i) Swaminathan, Craven & McMullan (1984); (j) Boese, Maulitz & Stellberg (1994); (k) Nijveldt & Vos (1988); (/) Kampermann, Ruble & Craven (1994).…”

Section: Compute Molecular Propertiesmentioning

confidence: 99%

Molecular electric moments and electric field gradients from X-ray diffraction data: model studies

Spackman¹,

Byrom²

1996

Acta Crystallogr Sect B

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Model X-ray data sets, with and without the inclusion of experimental thermal motion parameters, have been computed via Fourier transformation of ab initio molecular electron densities for 12 different molecular crystals. These datasets were then analysed with three different multipole models of varying sophistication and, from the multipole functions, molecular dipole and second moments, as well as electric field gradients (EFG's), at each nuclear site were computed and compared with results obtained from the original ab initio wavefunctions. The results provide valuable insight into the reliability of these properties, extracted in the same way from experimental X-ray data. Not all molecular systems display identical trends, but a general pattern is discernible. Specifically, dipole moments are typically underestimated by a small but significant amount (~ 10-15%), the trace of the second moment tensor is well determined but overestimated by a few per cent and electric field gradients at protons are confirmed to be well within reach of a careful charge density analysis of X-ray diffraction data.

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The crystal structure of deuterated benzene

Cited by 155 publications

References 9 publications

Microstructures of negative and positive azeotropes

Microstructures of negative and positive azeotropes

Dipole and quadrupole moments of molecules in crystals: A novel approach based on integration over Hirshfeld surfaces

Molecular electric moments and electric field gradients from X-ray diffraction data: model studies

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