The Crystal Structure of Lower Paraffins. IV. Refinement of the Crystal Structures of Pentane and Octane.

Mathisen, H.; Norman, Nico; Pedersen, Berit F.; Haug, Arne; Theorell, Hugo; Blinc, R.; Paušak, S.; Ehrenberg, L.; Dumanović, J.

doi:10.3891/acta.chem.scand.21-0127

Cited by 103 publications

(60 citation statements)

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“…8,9,11 This n-odd/n-even alternation of physical properties and INS pattern should be related to a distinct packing arrangement of the linear amines, which is expected to be tighter for even-membered molecules and less dense for n ) odd, similarly to that was previously recognized for n-alkanes. 31,32 Therefore, the TAM dispersion curves for the two sets of polyamines display only subtle differences.…”

Section: Mass (Frequencies) and Scattering Cross Section (Ins Intensimentioning

confidence: 99%

Transverse Acoustic Modes of Biogenic and α,ω-Polyamines: A Study by Inelastic Neutron Scattering and Raman Spectroscopies Coupled to DFT Calculations

2006

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A complete analysis of the transverse acoustic modes (TAMs) for the homologous series of R,ω-diamines (H 2 N(CH 2 ) n NH 2 ) (n ) 2-10, n ) 12) as well as for the biogenic polyamines spermidine and spermine was undertaken, by Raman and inelastic neutron scattering (INS) spectroscopies combined with density functional theory (DFT) calculations. A complete assignment of the whole set of TAMs was carried out, for both the undeuterated and N-deuterated species. 1,2-Diaminoethane was found to display exceptional behavior, probably due to the formation of dimers in the solid state. An n-even/n-odd dependence of the low frequency INS pattern was observed for these polyamines. The very good accordance between their INS experimental TAMs and the ones previously reported for the corresponding n-alkanes suggest a close conformational similarity between these systems.

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Section: Mass (Frequencies) and Scattering Cross Section (Ins Intensimentioning

confidence: 99%

Transverse Acoustic Modes of Biogenic and α,ω-Polyamines: A Study by Inelastic Neutron Scattering and Raman Spectroscopies Coupled to DFT Calculations

2006

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“…The experimental structures for pentane and octane were taken from the work of Mathisen, Norman & Pedersen (1967), and the structure of hexane from Norman & Mathisen (1961). The hydrogen-atom coordinates are not fully determined for hexane, so the tetrahedral axes were defined using dummy sites.…”

Section: Anisotropic Carbon Site-site Potentials For Saturated Hydrocmentioning

confidence: 99%

Model anisotropic intermolecular potentials for saturated hydrocarbons

Price¹

1986

Acta Crystallogr Sect B

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The use of explicit orientation-dependent functions, to represent the effects of non-spherical features in the molecular charge distribution, in model intermolecular pair potentials is developed in order to produce more accurate transferable anisotropic sitesite potentials for organic molecules. An isotropic atom-atom intermolecular potential-energy surface for methane is analysed using the orientation-dependent expansion functions appropriate to a pair of tetrahedral molecules, to determine the ability of a wide variety of one-centred anisotropic model potentials to reproduce the surface. The analysis is used to develop a simple anisotropic carbon potential scheme for CH3 and CH2 groups, which can predict the crystal structures of pentane, hexane and octane as accurately as the widely used isotropic atom-atom potential, and has the advantage of being more computationally efficient and more flexible for future development. The derivation of the appropriate orientationdependent functions for tetrahedral molecules, using angular momentum theory, in a form which is very convenient for crystal structure analysis is given. These functions are also used to examine the use of van der Waals radii to predict molecular packing.

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“…Even nalkane crystal series (6 ≤ n ≤ 26) have a triclinic structure [1][2][3][4][5][6], in which the lattice constants a, b, and the angle γ slightly depend on n; the lattice constant c and the angles α and β strongly depend on n, and interactions between molecules along a and b axes are strong and proportional to n, and those along c axis are very weak and independent of n ( Fig. 1).…”

Section: Introductionmentioning

confidence: 99%