Reasoning and Representation: the Sketching of Organic Chemical Reaction Mechanisms

For nearly a century organic chemists have developed a method of sketching chemical reaction mechanisms in order to reason-out the structural transformations that convert one set of molecules into another. Known informally as pushing electrons (or curly arrows), it is a form of chemical illustration in which a sequence of structures is drawn to represent the movement of electrons and nuclei from starting materials to final products. By pushing electrons, organic chemists use illustrations as a way of phrasing an idea or to argue what-if scenarios for chemical events.