chemical bond

A short essay by Frank Weinhold and Clark R. Landis

http://www.sciencemag.org/cgi/reprint/316/5821/61.pdf

chemical bond concept development:

1. Kekule et al. 19th century;

2. G.N.Lewis, 1916 "shared electron pair";

3. Valence Bond Method/Theory: In the 1930s, Pauling combined Hietler-London's quantum wavefunctions ansatz and Lewis' "pairing and sharing" of electrons ;

4. In the 1970s and after, VB was found to be inferior MO in calculations, localized chemical bonding concept met difficulty.

Two very famous comments:

"The more accurate the calculations become, the more the concepts tend to vanish into thin air”--R. S. Mulliken, J. Chem. Phys. 43, S2 (1965).

“the supercomputerhas dissolved the chemical bond”--B. Sutcliffe, Int. J. Quantum Chem. 58, 645 (1998).

5. In the 1980s, NBO and NRT(natural resonance theory) by Frank Weinhold et al. give Lewis bond a revival.

6. maximum bond order in the foreseeable future =6