scholarly journals Chiral recognition by fullerenes: CHFClBr enantiomers in the C82cage

2016 ◽  
Vol 18 (37) ◽  
pp. 26057-26068 ◽  
Author(s):  
Helena Dodziuk ◽  
Kenneth Ruud ◽  
Tatiana Korona ◽  
Taye B. Demissie
Keyword(s):  
Electrostatic Interactions ◽  
Chiral Recognition ◽  
Theoretical Studies ◽  
Stretching Vibration

Theoretical studies of complexes of the enantiomers of CHFClBr with C82-3 show that the too large guests are stabilized in the C82cage by electrostatic interactions. The sign of v(CH) stretching vibration of S-CHFClBr@C82-3 in the VCD spectrum is reversed as compared to that of the free guest. Spectra of the complexes exhibit differences.

Theoretical Study of the Physisorption of CO on Metal Oxide Surfaces Using the KSCED-DFT Approach

1998 ◽  
Vol 63 (9) ◽  
pp. 1447-1459 ◽  
Author(s):  
Nathalie Vulliermet ◽  
Tomasz A. Wesolowski ◽  
Jacques Weber
Keyword(s):  
Metal Oxide ◽  
Frequency Shift ◽  
Electron Density ◽  
Effective Potential ◽  
Theoretical Study ◽  
Adsorbed Molecule ◽  
Theoretical Studies ◽  
Metal Oxide Surfaces ◽  
Stretching Vibration ◽  
Good Agreement

Theoretical studies on structure and stretching frequency of the CO molecule physisorbed on the MgO(100) or ZnO(1010) surfaces are reported. The properties of the adsorbed molecule were investigated by means of the recently developed formalism of Kohn-Sham equations with constrained electron density (KSCED). The KSCED method makes it possible to divide a large system into two subsystems and to study one of them using Kohn-Sham-like equations with an effective potential which takes into account the interactions between subsystems. This method (KSCED) was shown to be adequate to study the properties of the CO molecule adsorbed on the MgO(100) surface as reported in a previous paper (Wesolowski et. al.: J. Mol. Struct., THEOCHEM, in press). The effect of the interactions with the surface on the CO stretching frequency and geometry was analyzed for vertically bound (C-down) CO at the Zn-site of the ZnO(1010) surface. The ZnO(1010) surface was represented using several cluster models: Zn2+, (ZnO3)4-, or Zn9O9 embedded in a matrix of point charges. The KSCED frequency shift of the CO stretching vibration is blue-shifted and in good agreement with experiment.

Template mediated crystal engineering

1994 ◽  
Vol 52 ◽  
pp. 480-481
Author(s):  
Brigid R. Heywood ◽  
S. Champ
Keyword(s):  
Crystal Engineering ◽  
Electrostatic Interactions ◽  
Alkyl Chain ◽  
Crystallographic Axis ◽  
Two Dimensional ◽  
Engineering Process ◽  
Solution Interface ◽  
Extensive Program ◽  
Geometric Homology ◽  
Long Alkyl Chain

Recent work on the crystallisation of inorganic crystals under compressed monomolecular surfactant films has shown that two dimensional templates can be used to promote the oriented nucleation of solids. When a suitable long alkyl chain surfactant is cast on the crystallisation media a monodispersied population of crystals forms exclusively at the monolayer/solution interface. Each crystal is aligned with a specific crystallographic axis perpendicular to the plane of the monolayer suggesting that nucleation is facilitated by recognition events between the nascent inorganic solid and the organic template.For example, monolayers of the long alkyl chain surfactant, stearic acid will promote the oriented nucleation of the calcium carbonate polymorph, calcite, on the (100) face, whereas compressed monolayers of n-eicosyl sulphate will induce calcite nucleation on the (001) face, (Figure 1 & 2). An extensive program of research has confirmed the general principle that molecular recognition events at the interface (including electrostatic interactions, geometric homology, stereochemical complementarity) can be used to promote the crystal engineering process.

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