1
|
Dorset DL, Baugh LS, Luo J, Shea KJ. Rectangular Chain Packing of Methyl-Branched Paraffins: Persistence of an Interchain Interaction and Forms of Disorder. J Phys Chem B 2011; 115:8858-63. [DOI: 10.1021/jp202495p] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Douglas L. Dorset
- ExxonMobil Research and Engineering, Corporate Strategic Research Laboratory, 1545 Route 22 East, Annandale, New Jersey 08801, United States
| | - Lisa Saunders Baugh
- ExxonMobil Research and Engineering, Corporate Strategic Research Laboratory, 1545 Route 22 East, Annandale, New Jersey 08801, United States
| | - Jun Luo
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Kenneth J. Shea
- Department of Chemistry, University of California, Irvine, California 92697, United States
| |
Collapse
|
3
|
Lord TD, Hobbs JK, Terry AE, Kvick Å, Hanna S. Variation of Lattice Parameters with Fold State in the Ultralong n-Alkanes. Macromolecules 2010. [DOI: 10.1021/ma902584z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Timothy D. Lord
- H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, U.K
- Beamline ID11, ESRF, 6 rue Jules Horowitz, BP220, 38043 Grenoble Cedex, France
| | - Jamie K. Hobbs
- Departments of Physics & Astronomy and Chemistry, University of Sheffield, Western Bank, Sheffield S10 2TN, U.K
| | - Ann E. Terry
- ISIS Science Diffraction & Muon Division, CCLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, U.K
| | - Åke Kvick
- Beamline ID11, ESRF, 6 rue Jules Horowitz, BP220, 38043 Grenoble Cedex, France
| | - Simon Hanna
- H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, U.K
| |
Collapse
|
4
|
Dorset DL. Electron crystallography of the polymethylene chain. 5. Three-dimensional structure of a Fischer-Tropsch wax. ACTA ACUST UNITED AC 2009. [DOI: 10.1524/zkri.216.4.234.23258] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
The crystal structure of a Fischer-Tropsch wax, Shell Callista 158, has bee determined in three dimensions from electron diffractio intensity data. Although there is an orthorhombic layer arrangement with apparent dimensions, a = 7.42, b = 4.96, c = 94.50 Å, true lamellae cannot form, due to a ‘nematocrystalline’ arrangement of very long chain components,generating a continuous chain direction through adjacent chain layer clusters. The structure is actually a superlattice of the Pnam cell observed for high molecular weight polyethylene.
Collapse
|
5
|
Fu J, Urquhart SG. Linear dichroism in the X-ray absorption spectra of linear n-alkanes. J Phys Chem A 2006; 109:11724-32. [PMID: 16366622 DOI: 10.1021/jp053016q] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The nature of the linear dichroism in the near-edge X-ray absorption fine structure (NEXAFS) spectra of linear n-alkanes is a matter of long-standing controversy. Linear dichroism in the carbon 1s --> sigma*(C-C) transition has been interpreted within a building block model and a molecular orbital model, leading to two different descriptions for the angular dependence of this feature. When used for measurement of molecular orientation, the application of these two different models will lead to different results. We have explored the linear dichroism in the carbon 1s NEXAFS spectra of single crystals of the linear n-alkane hexacontane (n-C60H122). An analysis of the angular dependence in this spectrum shows that the transition dipole moment associated with the carbon 1s --> sigma*(C-C) transition is oriented along the macromolecular chain axis, contradicting the predictions of the building block model. However, other transitions are observed in the sigma*(C-H) and the sigma*(C-C) bands that are orthogonal to the dominant transitions for each band. We also observe that radiation damage can be manifest in the form of molecular reorientation in highly ordered organic thin films.
Collapse
Affiliation(s)
- Juxia Fu
- Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewan, Canada S7N 5C9
| | | |
Collapse
|
7
|
Tashiro K, Tanaka I, Oohara T, Niimura N, Fujiwara S, Kamae T. Extraction of Hydrogen-Atom Positions in Polyethylene Crystal Lattice from Wide-Angle Neutron Diffraction Data Collected by a Two-Dimensional Imaging Plate System: Comparison with the X-ray and Electron Diffraction Results. Macromolecules 2004. [DOI: 10.1021/ma036003o] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kohji Tashiro
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan, Advanced Science Research Center, Japan Atomic Energy Institute, Tokai-mura, Ibaraki 319-1195, Japan, Institute of Materials Structure Science, High Energy Accelerator Research Organization, Oho 1-1, Tsukuba, Ibaraki 305-0801, Japan, and Department of Technology, Ibaraki University, Hitachi, Ibaraki 316-8511, Japan
| | - Ichiro Tanaka
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan, Advanced Science Research Center, Japan Atomic Energy Institute, Tokai-mura, Ibaraki 319-1195, Japan, Institute of Materials Structure Science, High Energy Accelerator Research Organization, Oho 1-1, Tsukuba, Ibaraki 305-0801, Japan, and Department of Technology, Ibaraki University, Hitachi, Ibaraki 316-8511, Japan
| | - Takashi Oohara
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan, Advanced Science Research Center, Japan Atomic Energy Institute, Tokai-mura, Ibaraki 319-1195, Japan, Institute of Materials Structure Science, High Energy Accelerator Research Organization, Oho 1-1, Tsukuba, Ibaraki 305-0801, Japan, and Department of Technology, Ibaraki University, Hitachi, Ibaraki 316-8511, Japan
| | - Nobuo Niimura
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan, Advanced Science Research Center, Japan Atomic Energy Institute, Tokai-mura, Ibaraki 319-1195, Japan, Institute of Materials Structure Science, High Energy Accelerator Research Organization, Oho 1-1, Tsukuba, Ibaraki 305-0801, Japan, and Department of Technology, Ibaraki University, Hitachi, Ibaraki 316-8511, Japan
| | - Satoru Fujiwara
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan, Advanced Science Research Center, Japan Atomic Energy Institute, Tokai-mura, Ibaraki 319-1195, Japan, Institute of Materials Structure Science, High Energy Accelerator Research Organization, Oho 1-1, Tsukuba, Ibaraki 305-0801, Japan, and Department of Technology, Ibaraki University, Hitachi, Ibaraki 316-8511, Japan
| | - Toshiya Kamae
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan, Advanced Science Research Center, Japan Atomic Energy Institute, Tokai-mura, Ibaraki 319-1195, Japan, Institute of Materials Structure Science, High Energy Accelerator Research Organization, Oho 1-1, Tsukuba, Ibaraki 305-0801, Japan, and Department of Technology, Ibaraki University, Hitachi, Ibaraki 316-8511, Japan
| |
Collapse
|
13
|
Dorset DL. Electron crystallography of organic and biological molecules--techniques and comparison to X-ray crystallographic results. Micron 1994; 25:423-30. [PMID: 7850349 DOI: 10.1016/0968-4328(94)00022-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In this review, it is shown how ab initio analyses of molecular crystal structures can be carried out with electron diffraction intensities and high-resolution, low-dose, electron micrographs, dispelling the long-held myth that such determinations are not possible. The results for small organics, polymethylene compounds, various polymers, and even intregral membrane proteins, are in good agreement with independent X-ray crystal structure determinations, which, however, were not needed to solve the crystallographic phase problem from the electron scattering data. The concept of electron crystallography benefits from the utility of electron micrographs for providing phase information, in addition to the standard 'direct' methods used nowadays by all crystallographers.
Collapse
Affiliation(s)
- D L Dorset
- Electron Diffraction Department, Medical Foundation of Buffalo, NY 14203
| |
Collapse
|
16
|
Dorset DL, Zhang WP. Lamellar packing of a chiral N,N-dimethylphosphatidylethanolamine: electron diffraction. Evidence for a lecithin-type headgroup conformation. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1028:299-303. [PMID: 2223801 DOI: 10.1016/0005-2736(90)90179-r] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Lamellar electron diffraction intensity data from epitaxially crystallized 1,2-dipalmitoyl-sn-glycerophospho-N,N-dimethylethanolamine were used to determine the layer packing in order to compare the chiral structure to the crystal structure of a racemic homologue. After finding the chain orientation, the structure was determined by interpretation of the Patterson function, followed by independent crystallographic phase assignments with conventional direct methods (use of three phase structure invariants). The phase determination was verified by a translational search with a molecular model based on a similar lecithin structure. The final R-value is 0.29, and this is lowered to 0.18 after a correction is made for incoherent multiple electron scattering. The layer packing is found to be very much like that of a diacyl phosphatidylcholine with the N,N-dimethylethanolamine moiety parallel to the bilayer surface rather than the perpendicular arrangement of headgroups involved in an interdigitated layer, as seen for racemic homolog.
Collapse
Affiliation(s)
- D L Dorset
- Electron Diffraction Department, Medical Foundation of Buffalo, Inc., NY 14203
| | | |
Collapse
|