Map of electrostatic potential

Fig. 8 The maps of electrostatic potential A - 1,3,5-trinitrobenzene B - siloxane site of clay minerals. Red color - area of negative electrostatic potential blue color - area of positive electrostatic potential.

Fig. 21.3 Two views of the optimized structure and maps of electrostatic potential of thymine adsorbed on hydrated tetrahedral and octahedral surface of kaolinite mineral (a — K(3t)NaW-TH, b - K(3o)NaW-TH) obtained at the B3LYP/6-31G(d) level of theory...

The characteristics of adsorption binding of thymine and uracil were confirmed by the maps of electrostatic potential drawn for all complexes. The isomorphic substitution and the presence of the cation in both fragments affect the electron redistribution and this influence varies based on the surface type. 

There are two contributing resonance structures for an anion called acetaldehyde enolate, whose condensed molecular formula is CH2CHO . Draw the two resonance contributors and the resonance hybrid, then consider the map of electrostatic potential (MEP) shown below for this anion. Comment on whether the MEP is consistent or not with predominance of the resonance contributor you would have predicted to be represented most strongly in the hybrid. 

FIGURE 2.4 (a) The dipole moment of chloromethane arises mainly from the highly polar carbon-chlorine bond. (t>) A map of electrostatic potential illustrates the polarity of chloromethane. 

FIGURE 3.10 Maps of electrostatic potential at approximately the bond density surface for acetic acid and ethanol. The positive charge at the carbonyl carbon of acetic acid is evident in the blue color of the electrostatic potential map at that position, as compared to the hydroxyl carbon of ethanol. The inductive electron-withdrawing effect of the carbonyl group in carboxylic acids contributes to the acidity of this functional group. 

Formamide (HCONH2) has a pA of approximately 25. Predict, based on the map of electrostatic potential for formamide shown here, which hydrogen atom(s) has this pA value. Support your conclusion with arguments having to do with the electronic structure of formamide. 

FIGURE 6.8 Maps of electrostatic potential for (a) fert-butyl (S"). (b) isopropyl (2°), (c) ethyl (1°), and (cf) methyl carbocations show the trend from greater to lesser delocalization (stabilization) of the positive charge in these structures. Less blue color indicates greater delocalization of the positive charge. (The structures are mapped on the same scale of electrostatic potential to allow direct comparison.)... 

Draw all of the contributing resonance structures and the resonance hybrid for the carbocation that would result from ionization of bromine from 5-bromo-1,3-pentadiene. Open the computer molecular model at the book s website depicting a map of electrostatic potential for the pentadienyl carbocation. Based on the model, which is the most important contributing resonance structure for this cation Is this consistent with what you would have predicted based on your knowledge of relative carbocation stabilities ... 

A map of electrostatic potential for acetone shows the polarity of the carbonyl C=0 bond. 

Enamines are good nucleophiles. Examination of the resonance structures that follow show that we should expect enamines to have both a nucleophilic nitrogen and a nucleophilic carbon. A map of electrostatic potential highlights the nucleophilic region of an enamine. 

The well documented PCILO method [9], modified to do local and relaxed minimizations, was employed in all the conformation studies. The maps of electrostatic potentials were obtained from deorthogonalized INDO molecular orbitals from a procedure described elsewhere [10]. 

Figure 2.1 A calculated map of electrostatic potential for hydrogen chloride showing regions of relatively more negative charge in red and more positive charge in blue. Negative charge is clearly localized near the chlorine, resulting in a strong dipole moment for the molecule.

Calculated Molecular Models Maps of Electrostatic Potential... 

Figure 3.2 The effect of increasing electronegativity among elements from left to right in the first row of the periodic table is evident in these maps of electrostatic potential for methane, ammonia, water, and hydrogen fluoride.

Halogen atom size increases as we go down the periodic table fluorine atoms are the smallest and iodine atoms the largest. Consequently, the carbon-halogen bond length increases and carbon-halogen bond strength decreases as we go down the periodic table (Table 6.1). Maps of electrostatic potential (see Table 6.1) at the van der Waals surface for the four methyl... 

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