Effect of electronegativity

Electronegativity The effect of electronegativity on acidity is evident m the following senes involving bonds between hydrogen and the second row elements C N O and F... 

The deshieldmg effects of electronegative substituents are cumulative as the chem ical shifts for various chlorinated derivatives of methane indicate... 

The effect of electronegative modifiers on the activation energy of CO desorption, Ed, and on the corresponding pre-exponential factor, vd, can be quantified by analysis of the TPD spectra at very low CO coverages. The... 

The effect of electronegative additives on the adsorption of ethylene on transition metal surfaces is similar to the effect of S or C adatoms on the adsorption of other unsaturated hydrocarbons.6 For example the addition of C or S atoms on Mo(100) inhibits the complete decomposition (dehydrogenation) of butadiene and butene, which are almost completely decomposed on the clean surface.108 Steric hindrance plays the main role in certain cases, i.e the addition of the electronegative adatoms results in blocking of the sites available for hydrocarbon adsorption. The same effect has been observed for saturated hydrocarbons.108,109 Overall, however, and at least for low coverages where geometric hindrance plays a limited role, electronegative promoters stabilize the adsorption of ethylene and other unsaturated and saturated hydrocarbons on metal surfaces. 

Brenninkmeijer, C. A. and Mook, W. G., The Effect of Electronegative Impurities on C02 Proportional Counting, Ninth International Radiocarbon Conference, University of California, Los Angeles and San Diego, 1976. 

Fig. 42. The effect of electronegativity on the 2py- a interaction. H is assumed to have an artificially greater electronegativity than H. The 2py-H interaction is stronger than the 2py-H interaction...

The structures of some stable stannylenes, such as several amino-, " alkoxy-, and arylthio-substituted intermediates, have been revealed by X-ray crystallography. They are monomeric crystals and the tin atom has the coordination number 2. The divalent tin in such compounds is stabilized by the effects of electronegativity of the ligand atoms and by the donation of the lone-pair electrons to the vacant 5p orbital of the tin. Although the first monomeric dialkyl- and diaryl- stannylenes in... 

The effects of electronegativity differences on the bonding in heteronuclear diatomic molecules... 

Brook and coworkers have studied the effects of electronegative groups on silicon on the reactivities of vinylsilanes115. Unlike the substitution reaction of 1-trimethylsilylprop-1-ene with acetyl chloride (equation 51a) the major product of the reaction of fi-trichlorosilylstyrene with phenylacetyl chloride arises from addition, as shown in equation 51b. 

De Rider, M. L., Wilkens, S. J., Waddell, M. J., Bretcher, L. E., Weinhold, F., Raines, R. T., and Markely, J. L. (2002). Collagen stability Insights from NMR spectroscopic and hybrid density functional computational investigations of the effect of electronegative substituents on prolyl ring conformations. J. Am. Chem. Soc. 124, 2497-2505. 

Figure 3-1 illustrates the effect of electronegativity differences on bond polarity. 

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