Whatever happened to Linnett double-quartet (LDQ) theory?

Resumen

This paper discuss one recent episode in the history of chemistry which currently has received little attention in the scientific realism debate: the rise and ‘‘apparent’’ fall of an approximate model of the chemical bond known as Linnett double-quartet theory. In 1961 Linnett published a paper in the Journal of the American Chemical Society entitled ‘‘A Modification of the Lewis-Langmuir Octet Rule’’ in which he suggested certain changes in G. N. Lewis’s original views on the role of the electron pair in covalent bond formation based on an explicit consideration of the effects of electron spin --- a property of the electron unknown to Lewis in 1916. Although his theory produced outstanding predictions, it is now forgotten.