Abstract

Summary Linus Pauling played a key role in creating valence-bond theory, one of two competing theories of the chemical bond that appeared in the first half of the 20th century. While the chemical community preferred his theory over molecular-orbital theory for a number of years, valence-bond theory began to fall into disuse during the 1950s. This shift in the chemical community's perception of Pauling's theory motivated Pauling to defend the theory, and he did so in a peculiar way. Rather than publishing a defence of the full theory in leading journals of the day, Pauling published a defence of a particular model of the double bond predicted by the theory in a revised edition of his famous textbook, The Nature of the Chemical Bond. This paper explores that peculiar choice by considering both the circumstances that brought about the defence and the mathematical apparatus Pauling employed, using new discoveries from the Ava Helen and Linus Pauling Papers archive.