Electronegativity equation

Hz, Vp jj = 2430 cm-l) ( 1) and other equatorial hydridophos-phoranes (3). These observations are reconciled with an apical P-H disposition for in solution on the basis of a correlation between Jpjj and ligand electronegativity (Equation 1). This was developed using data for a large number of hydridophosphoranes... 

Ehomo Elumo EN HD Descriptors Based on Molecular Orbital Energies (Section IV.A and B) Energy of the highest occupied molecular orbital (Equation 6.42) Energy of the lowest unoccupied molecular orbital (Equation 6.43) Molecular electronegativity (Equation 6.45) Molecular hardness (Equation 6.46)... 

Matsunaga, N. Rogers, D. W. Zavitsas, A. A. Pauling s electronegativity equation and a new corollary accurately predict bond dissociation enthalpies and enhance current understanding of the nature of the chemical bond, J. Org. Chem. 2003, 68, 3158-3172. 

Figure 3.2. Correlation between Gibbs energy and differences of sum of average electronegativities (equation 3.5) for the synthesis of complex oxides. a - alkaline earth silicates (common anion), b - calcium compounds (common cation)...

It is clear from this formulation that if we read electronegativity equation starting with the right hand of it we get the consistency of the present picture when the competition between the density and its gradient approaches the atomic radius limit (the HOMO radius) then the equivalent potential of the evolved electrons identifies the Mulliken electronegativity... 

The problem appears when we like to solve above electronegativity equations respecting the atomic radii R, because the appearance of the... 

Standard heat of formation per bond of hydrides (g) of nonmetallic elements, compared with values calculated by the electronegativity equation. 

Chemical potential is correlated with ionization energy and electron affinity, and as a result, also with Mulliken electronegativity (Equation [3.7]). 

Electronegativity Equation and a New Corollary Accurately Predict Bond Dissociation Enthalpies and Enhance Current Understanding of the Nature of the Chemical Bond. 

Understand the relationship between bond enthalpy terms and electronegativity differences embodied in Pauling s electronegativity equation, and calculate one from the other. (Question 4.4)... 

Schomaker-StevensoD equation The equation a B = a + fl 0 09 (Xa - X ) relating the bond length to the individual radii rp and Tb of the two atoms concerned and the electronegativities Xp and X of the two atoms concerned in the bond. This relation is only empirical and is not very accurate. 

In this equation, the electronegativity of an atom is related to its ionization potential, 1, and its electron affinity, E. Mulhken already pointed out that in this definition the ionization potential, and the electron affinity, E, of valence states have to be used. This idea was further elaborated by Hinze et al. [30, 31], who introduced the concept of orbital electronegativity. 

As the atom (A) to which H is bonded becomes more electronegative the polarization H—A becomes more pronounced and H is more easily lost as H An alternative approach to the same conclusion is based on the equation for proton transfer especially with regard to the flow of electrons as shown by curved arrows... 

The basic equations of ZINDO/1 are the same as those in INDO, except for Uj y. Instead of using the electronegativity in INDO, ZINDO/1 uses the ionization potential for computing Uj y. 

Later methods, especially that of Gordy (1955), and later Allred and Rochow (1958) make use of screening constants of the electron strucmre for the nuclear charge of each atom. This determines die attraction between the nucleus of the atom and an electron outside the normal electron complement, and is die effective nuclear charge. The empirical equation for the values of electronegativity obtained in this manner by Allred and Rochow is... 

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... 

In general, the dissection of substituertt effects need not be limited to resonance and polar components, vdiich are of special prominence in reactions of aromatic compounds.. ny type of substituent interaction with a reaction center could be characterized by a substituent constant characteristic of the particular type of interaction and a reaction parameter indicating the sensitivity of the reaction series to that particular type of interactioa For example, it has been suggested that electronegativity and polarizability can be treated as substituent effects separate from polar and resonance effects. This gives rise to the equation... 

Electronegatively substituted acetylenes, such as dimethyl acetylenedicar-boxylate, do not react under normal conditions but will add the elements of hydrogen fluoride by reaction with fluoride ion (e g, CsF or tetraalkylammonium dihydrogen trifluoride) and a proton source under phase-transfer conditions [49, 50] (equation 8)... 

In contrast to hydrogen-type ethers, a-haloethers, both linear and cyclic, are relatively easily cleaved by anhydrous hydrogen fluoride. Bis( 1,1 -difluoroalkyl) ethers are converted to 1,1,1 -trifluoroalkanes and alkanoyl fluorides The cleavage temperature depends on the substituents present ethers having no electronegative substituents other than a-fluorines are readily cleaved below 20 °C, 3-halo-1,1-di fluoroethers require approximately 70 °C, but 2-halo-1,1-difluoroethers are prac tically resistant toward hydrogen fluoride [/I (equation 1)... 

The elimination of water from a fluorinated compound generally follows a reaction path similar to that of its nonfluorinated counterpart, although the presence of the highly electronegative fluorine atoms may have unexpected effects Various monofluoro alcohols can be dehydrated via their tosyl esters at 75 C by using potassium rert-butoxide [80] (equation 50)... 

Edwards two-parameter equation 549 Electrochemical oxidation of sulphides 76, 252, 253 of sulphoxides 968, 987, 1043 Electrochemical reduction of sulphones 962, 963, 1002-1041 of sulphoxides 933, 1041, 1042 Electronegativity, of the sulphur atom 584 Electronic effects 390, 484-535 Electron scavengers 892, 896 Electron spin resonance spectroscopy 874, 890-895, 1050-1055, 1082, 1083, 1090-1093... 

Electropositive adsorbates cause a decrease in the work function, of surfaces while electronegative adsorbates increase O. The variation in with the coverage, 0j, of an adsorbate is described by the Helmholtz equation ... 

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