Electronegativity differences

Bond Properties. Bond strengths, bond lengths, and atom electronegativity differences of various phosphoms—atom linkages are given in... 

Table 4. Properties and Electronegativity Differences of Phosphorus—Atom Bonds ...

Pauling s electronegativity difference, where represents the electronegativity of atom X. 

Styrene readily copolymerizes with many other monomers spontaneously. The styrene double bond is electronegative on account of the donating effect of the phenyl ring. Monomers that have electron-withdrawiag substituents, eg, acrylonitrile and maleic anhydride, tend to copolymerize most readily with styrene because their electropositive double bonds are attached to the electronegative styrene double bond. Spontaneous copolymerization experiments of many different monomer pair combiaations iadicate that the mechanism of initiation changes with the relative electronegativity difference between the monomer pairs (185). 

A guide to tire stabilities of inter-metallic compounds can be obtained from the semi-empirical model of Miedema et al. (loc. cit.), in which the heat of interaction between two elements is determined by a contribution arising from the difference in work functions, A0, of tire elements, which leads to an exothermic contribution, and tire difference in the electron concentration at tire periphery of the atoms, A w, which leads to an endothermic contribution. The latter term is referred to in metal physics as the concentration of electrons at the periphery of the Wigner-Seitz cell which contains the nucleus and elecUonic structure of each metal atom within the atomic volume in the metallic state. This term is also closely related to tire bulk modulus of each element. The work function difference is very similar to the electronegativity difference. The equation which is used in tire Miedema treatment to... 

Why do free-radical reactions involving neutral reactants and intermediates respond to substituent changes that modify electron distribution One explanation has been based on the idea that there would be some polar character in the transition state because of the electronegativity differences of the reacting atoms ... 

All three elements combine readily with most metals and many non-metals to form binary chalcogenides. Indeed, selenides and tellurides are the most common mineral forms of these elements (p. 748). Nonstoichiometry abounds, particularly for compounds with the transition elements (where electronegativity differences are minimal and variable valency is favoured), and many of the chalcogenides can be considered... 

What electronegativity difference, large or small, creates a more polar bond A more covalent bond ... 

Hydrocarbons normally have very small dipole momen Why (Hint Consider the relationship betwe electronegativity differences and dipole momer established above for hydrogen halides.) Does sing methylene possess a small dipole moment Explain. W1 direction do you expect singlet methylene s dipole point Explain. In what direction does it point ... 

SOLUTION The data in Fig. 2.12 show that electronegativity differences decrease from 1 HC1 to HI, and so the dipole moments decrease as well. Therefore, dipole-dipole forces decrease, too, a trend suggesting that the boiling points should decrease from HQ to HI. This prediction conflicts with the data so we examine the London forces. The number of electrons in a molecule increases from HQ to HI, and so the strength of the London interaction increases, too. Therefore, the boiling points should increase from HCl to HI, in accord with the data. This analysis suggests that London forces dominate dipole-dipole interactions for these molecules. 

A number of years ago an equation was proposed13 for calculating the partial ionic character of a a bond between two atoms A and B from their electronegativity difference sa — b... 

Partial Ionic Character op Bonds in Relation to Electronegativity Difference... 

The discussion of interatomic distances in salts of oxygen acids of the second-row elements is presented in Table IV. In the first row of this table, below the names of the salts, there are given values of the electronegativity difference xa — xb, in the second row the sum of the single-bond radii, in the third row the Schomaker-Stevenson correction, and in the fourth row the single-bond interatomic distance. The next row contains the fractional amount of ionic character of the a bond, as given by the electronegativity difference with use of Table... 

Nevertheless, Murrell, Kettle, and Tedder conclude in their book on valence theory57 that there is no correlation between the electric dipole moment of a bond and the electronegativity difference. They have plotted the values of the electric dipole moments of eight bonds against the difference in the values of the Mulliken electronegativity (see Figure 1-2). (The bond moments for OH, NH, PH, NF, and PF are calculated from the... 

Increasing content of the large M E(MRE)-metals as well as increasing electronegativity differences reduce the formation of boron-boron aggregates, with... 

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