Electrostatic potential ethane

Electrostatic potential maps for ethyne, ethene, and ethane ... 

An electrostatic potential map for ethane The electron pair of the n bond is shows the higher density of negative distributed throughout both lobes... 

We have pointed out earlier that the C-C bonds in strained hydrocarbons have negative electrostatic potentials near their midpoints [39,53]. (This is not observed for more typical C-C bonds, such as those in ethane and propane.) In general, these potentials are more negative, and the calculated strain in the individual bonds is greater, in three-membered rings than in four-membered rings [53-58]. (We measure bond strain by the extent to which the actual bond path differs from a reference path [53,54,57].)... 

The effect of hybridization and effective electronegativity on acidity is borne out in the calculated electrostatic potential maps for ethyne, ethene, and ethane shown in Fig. 3.4. Some positive charge (indicated by blue color) is clearly evident on the hydrogens of ethyne pK = 25), but almost no positive charge is present on the hydrogens of ethene and ethane (both having pK values more than 20 units greater than ethyne). 

The effect of hybridization on acidity is borne out in the calculated electrostatic potential maps for ethyne, ethene, and ethane shown in Fig. 3.4. Some positive charge (indicated... 

Figure 15 (a) 3D modelof DDT (l,l,l-trichloro-2,2-bis(4-chlorphenyl)ethane). The dots color indicates the electrostatic potential, (b) The... 

Electrostatic potential maps for the staggered and eclipsed conformations of ethane are shown in the margin. In the staggered conformation, the hydrogen atoms (in the blue regions) are as far apart from one another as possible, and in the eclipsed conformation, they are as close as possible. 

We studied, by GCMC simulation [1], the adsorption of ethane and carbon dioxide on pure-silica MCM-41 and on MCM-41 with surface phenyl and aminopropyl groups. The fluid-fluid and fluid-solid potentials took into account dispersion and, where appropriate, electrostatic interactions. The surface groups - phenyl and aminopropyl - are modelled as flexible chain molecules. The solid-fluid potentials are transferable that is, they are applicable to all the oxide materials we have studied, and are not optimised for particular materials this is an indicator of the consistency of the approach. The silicon atoms are ignored in the simulation of adsorption. Further details of the kMC and GCMC simulation methods are given in reference [2]. 

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