Violently Twisted and Strained Organic Molecules: A Descriptor System for Simple Coronoid Aromatics with a Moebius Half-Twist and Semiempirical Calculations on the Moebius Analogs of Coronene

1994 ◽  
Vol 34 (2) ◽  
pp. 252-258 ◽  
Author(s):  
Robert W. Zoellner ◽  
John F. Krebs ◽  
David M. Browne
Keyword(s):  
Organic Molecules ◽  
Semiempirical Calculations ◽  
Descriptor System ◽  
Half Twist

QSPR Models for Predicting of the Melting Points and Refractive Indices for Inorganic Substances

2020 ◽  
Vol 5 (1) ◽  
pp. 1-21
Author(s):  
Victor E. Kuz'min ◽  
Liudmila N. Ognichenko ◽  
Viktor F. Zinchenko ◽  
Anatoly G. Artemenko ◽  
Angela O. Shyrykalova ◽  
...  
Keyword(s):  
Organic Molecules ◽  
Inorganic Compounds ◽  
Descriptor Systems ◽  
Descriptor System ◽  
Refractive Indices ◽  
Melting Points ◽  
Optical Film ◽  
Inorganic Substances ◽  
Film Forming ◽  
The Mean

The QSPR methodology is very promising for the creation of new materials, including materials based on inorganic compounds. However, the majority of QSPR descriptor systems are applicable only for organic molecules. In this work the 1D - QSPR descriptor system is proposed for analysis of the properties of various inorganic compounds. These descriptors are easily accessible, as they describe the most fundamental atom properties. The combinatorial schemes for computing these descriptors provide for their wide variety. The effectiveness of the proposed approach has been demonstrated to study the refractive indices and melting points of various inorganic compounds - components of potential optical film-forming materials. The developed QSPR models are suitable for the evaluative virtual screening of inorganic compounds; the mean relative error of prediction is 6 - 15%. The interpretation of the developed models reflects the nature of interatomic interactions in compounds with ionic structure.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

Direct phase determination in electron crystallography: small organic molecules

1992 ◽  
Vol 50 (2) ◽  
pp. 1166-1167
Author(s):  
Douglas L. Dorset
Keyword(s):  
Organic Molecules ◽  
Data Sets ◽  
Temperature Structure ◽  
3D Analysis ◽  
Intensity Data ◽  
Electron Crystallography ◽  
Phase Determination ◽  
Measured Intensity ◽  
3D Data

The quantitative use of electron diffraction intensity data for the determination of crystal structures represents the pioneering achievement in the electron crystallography of organic molecules, an effort largely begun by B. K. Vainshtein and his co-workers. However, despite numerous representative structure analyses yielding results consistent with X-ray determination, this entire effort was viewed with considerable mistrust by many crystallographers. This was no doubt due to the rather high crystallographic R-factors reported for some structures and, more importantly, the failure to convince many skeptics that the measured intensity data were adequate for ab initio structure determinations.We have recently demonstrated the utility of these data sets for structure analyses by direct phase determination based on the probabilistic estimate of three- and four-phase structure invariant sums. Examples include the structure of diketopiperazine using Vainshtein's 3D data, a similar 3D analysis of the room temperature structure of thiourea, and a zonal determination of the urea structure, the latter also based on data collected by the Moscow group.

A MOLECULAR DYNAMICS STUDY OF ELECTRONIC SPUTTERING OF LARGE ORGANIC MOLECULES

1989 ◽  
Vol 50 (C2) ◽  
pp. C2-33-C2-35 ◽  
Author(s):  
D. FENYÖ ◽  
B. U.R. SUNDQVIST ◽  
B. KARLSSON ◽  
R. E. JOHNSON
Keyword(s):  
Molecular Dynamics ◽  
Organic Molecules
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