Pauling’s, definition

The question is, therefore, should the C-H 0=C interaction be referred to as a hydrogen bond, even though there is every reason to suspect that the carbon atom is not electronegative and may even carry a net positive charge By Pauling s definition, the answer is no. By Pimental and McClellan s definition, the answer is yes. ... 

Pauling s definition has not been improved upon The power of an atom in a... 

To justify such a description within quantum mechanics we are led into a consideration of ionic and covEilent contributions to an approximate wave function. If covalent contributions are minor, the bond is said to be ionic in character, and the electrostatic model is considered to be applicable. Unfortunately, the terms ionic character and covalent character are used with various meanings. This is so, in part, because the rapid development of chemical bond theory has caused a drift of the meanings of these terms over the past two decades. Pauling s definitions, as presented in his book (1585, p. 48), no doubt represent the intent of most workers as of 1940. He concluded that there is a covalent bond between two atoms X and Y if the dissociation energy of X—is the mean of the dissociation energies of X— X and Y— Y. If the dissociation energy of X— Y exceeds this mean, the excess is attributed to additional ionic character of the bond. This criterion furnishes the basis for his scale of electronegativity, and ionic character is inter-... 

This definition takes us naturally to the following question are all attractive interactions bonds which can be rewritten as where do we put the bonds This issue is faced in complex molecules and intermolecular aggregates, and originates in the fact that Pauling s definition (except for the trivial case of a diatomic molecule) only allows to identify the existence of a bond, but not the atoms involved in it. We can illustrate the problem in two examples, selected as prototypes of intramolecular and intermolecular bonds where do we plot the bonds in benzene and in water dimer ... 

Pauling s definition is exhaustive only for interactions between two atoms for instance, the van der Waals bond in the Ar Ar interaction, or the bond in the H2 molecule. However, for more complex systems, it only recognizes the existence of a bond, but not the atoms involved in such a bond, or how many bonds are present. For instance, Pauling s definition recognizes that benzene is an entity with bonds, but does not determine their number or the atoms involved. The same is true for intermolecular bonds, where it cannot determine how many bonds can be found in... 

Gibbs GV, Rosso KM, Cox DF, Boisen MBP Jr (2003) A physical basis for Pauling s definition of bond strength. Phys Chtan Miner 30 317—320... 

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