Electron crystal structure analysis of small organic molecules

1985 ◽  
Vol 2 (2) ◽  
pp. 89-128 ◽  
Author(s):  
Douglas L. Dorset
Keyword(s):  
Crystal Structure ◽  
Structure Analysis ◽  
Organic Molecules ◽  
Crystal Structure Analysis ◽  
Small Organic Molecules ◽  
Electron Crystal

Synthesis of New 7,8-Dioxa[6]helicenes with Triazole Rings as Potential Molecular Tweezers

Synlett ◽  
2019 ◽  
Vol 30 (13) ◽  
pp. 1546-1550 ◽  
Author(s):  
Nilay Kasabali ◽  
Hande Gunduz ◽  
Kerem Kaya ◽  
Volkan Kumbaraci ◽  
Naciye Talinli
Keyword(s):  
Crystal Structure ◽  
Metal Ions ◽  
Structure Analysis ◽  
Organic Molecules ◽  
Crystal Structure Analysis ◽  
Molecular Tweezers ◽  
Dimeric Structure

This study introduces new triazole-linked host compounds, which have been synthesized from 7,8-dioxa-bisnaphthalene and 7,8-dioxa[6]helicenes. These compounds have different cavities depending on being ‘v’-shaped or helicene structures. The dimeric structure of 7,8-dioxa-bisnaphthalene has also been obtained and crystal structure analysis confirmed that it contains an unusual seven-membered dihydrooxepine ring. All synthesized compounds can act as molecular tweezers for organic molecules and also metal ions.

Quantitative Crystal Structure Analysis In The Electron Microscope

1987 ◽  
Vol 45 ◽  
pp. 434-437
Author(s):  
Douglas L. Dorset
Keyword(s):  
Electron Microscope ◽  
Structure Analysis ◽  
Organic Molecules ◽  
Analytical Techniques ◽  
Crystal Structure Analysis ◽  
Linear Polymers ◽  
X Ray Diffraction ◽  
Electron Crystallography ◽  
Small Organic Molecules ◽  
X Ray

Electron crystallography is a term which has emerged in the past few years to describe the quantitative structure analysis of microcrystalline preparations in the electron microscope. The field represents the confluence of two techniques, i.e. the ultramicroscopic capabilities of the electron microscope coupled with analytical techniques long in use by X-ray crystallographers. In the area of organic materials, the most visible success of the technique to date has been in the structure analysis of thin protein microcrystals typically to ca20 Å resolution but sometimes out to e.g. 7 Å and, in this field, there has been considerable effort by an increasing number of laboratories.Although the electron crystallography of small organic molecules and linear polymers has a much longer history than the application to globular proteins, one cannot cite an overwhelming enthusiasm for this technique, despite its promise as a probe for molecules which are not easily crystallized to sample sizes useful for single crystal X-ray diffraction measurements.

Electron crystal structure analysis of biomembrane lipids

1983 ◽  
Vol 41 ◽  
pp. 632-633
Author(s):  
Douglas L. Dorset
Keyword(s):  
Crystal Structure ◽  
Electron Diffraction ◽  
Structure Analysis ◽  
Diffraction Theory ◽  
Crystal Structure Analysis ◽  
Cell Axis ◽  
X Ray ◽  
Alkyl Chains ◽  
Phospholipid Structure ◽  
Electron Crystal

Because of the well-known sample crystallization difficulties which often hinder the X-ray crystal structure analysis of many long-chain lipids, Parsons and Nyburg were the first to attempt the crystallographic elucidation of a phospholipid structure using electron diffraction intensity data from more readily-available microcrystals. Subsequent electron diffraction studies of various lipids in this laboratory over the past decade have revealed a number of peculiar features of such data-particularly if these are expected to resemble X-ray data. These observations have led to a physically reasonable overview of the problem based on well-established diffraction theory and have permitted the derivation of useful analytical procedures for electron crystal structure determination. It is interesting to note that the appropriate procedure is dependent on the method used for specimen crystallization.Lipid crystals grown from solution are typically plate-like with long alkyl chains packing with axes more or less perpendicular to the best developed crystal face ; an incident electron beam thus parallels the longest unit cell axis.

Electron crystal structure analysis of phospholipids and their solid solutions

1986 ◽  
Vol 44 ◽  
pp. 76-77
Author(s):  
Douglas L. Dorset ◽  
Andrew K. Massalski ◽  
John R. Fryer
Keyword(s):  
Crystal Structure ◽  
Structure Analysis ◽  
Molecular Conformation ◽  
Crystal Structure Analysis ◽  
Electron Diffraction Data ◽  
Head Group ◽  
Polar Head Group ◽  
X Ray ◽  
Structure Determinations ◽  
Electron Crystal

Epitaxially crystallized phosphatidylethanolamines produce (Fig. 1) (001) electron diffraction data similar in resolution to X-ray data from oriented multilamellae. An attemped crystal structure analysis with such data based on a rigid body translation of the molecular conformation found in the X-ray crystal structure of the racemic dilauroyl homolog yielded a structural solution unlike that found in our re-analysis of the low angle X-ray data. The X-ray analysis, like other phospholipid crystal structure determinations, indicate that the z-component of the polar head group packing must place phosphorus atoms 4 to 5Å apart in the absence of solvent. The Patterson functions computed from electron or X-ray data are also consistent with this thesis.

Crystal structure analysis of 4-R-phenyl-2,6-dimethyl-3,5-N-(dimethylcarbamoyl)-1,4-dihydropyridines [R=2-nitro (1), 4-methoxy (2) and 3,4-dichloro (3)]

1998 ◽  
Vol 213 (3) ◽  
Author(s):  
M. Bidya Sagar ◽  
K. Ravikumar ◽  
Y. S. Sadanandam
Keyword(s):  
Crystal Structure ◽  
Calcium Channel ◽  
Structure Analysis ◽  
Crystal Structure Analysis ◽  
Calcium Channel Antagonists

AbstractThe crystallographic characterization of the following three calcium channel antagonists is reported here: 2,6-dimethyl-3,5-dicarbamoyl-4-[2-nitro]-1,4-dihydropyridine (

scholarly journals Combined Use of Structure Analysis, Studies of Molecular Association in Solution, and Molecular Modelling to Understand the Different Propensities of Dihydroxybenzoic Acids to Form Solid Phases

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 734
Author(s):  
Aija Trimdale ◽  
Anatoly Mishnev ◽  
Agris Bērziņš
Keyword(s):  
Crystal Structure ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Structure Analysis ◽  
Crystal Structure Analysis ◽  
Molecular Association ◽  
Hydroxyl Groups ◽  
Solid Phases ◽  
Solvent Molecules ◽  
Dynamics Simulations

The arrangement of hydroxyl groups in the benzene ring has a significant effect on the propensity of dihydroxybenzoic acids (diOHBAs) to form different solid phases when crystallized from solution. All six diOHBAs were categorized into distinctive groups according to the solid phases obtained when crystallized from selected solvents. A combined study using crystal structure and molecule electrostatic potential surface analysis, as well as an exploration of molecular association in solution using spectroscopic methods and molecular dynamics simulations were used to determine the possible mechanism of how the location of the phenolic hydroxyl groups affect the diversity of solid phases formed by the diOHBAs. The crystal structure analysis showed that classical carboxylic acid homodimers and ring-like hydrogen bond motifs consisting of six diOHBA molecules are prominently present in almost all analyzed crystal structures. Both experimental spectroscopic investigations and molecular dynamics simulations indicated that the extent of intramolecular bonding between carboxyl and hydroxyl groups in solution has the most significant impact on the solid phases formed by the diOHBAs. Additionally, the extent of hydrogen bonding with solvent molecules and the mean lifetime of solute–solvent associates formed by diOHBAs and 2-propanol were also investigated.

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