Remarks on the Theory of Aromatic Free Radicals

Abstract

In the quantum-mechanical treatment of the benzene molecule (and of other aromatic molecules) the approximation is usually made of neglecting the pairs of electrons which are considered to form bonds in the plane of the ring. The problem then becomes one of discussing the wave function which can be constructed for the remaining electrons by use of the p, orbitals, one for each carbon atom. This discussion can be made either by the molecular orbital method or by the valence bond method, the results being in general agreement. The treatment of a free radical such as phenylmethyl is closely similar, seven p, orbitals and seven electrons being considered for this molecule. It is found convenient in applying the valence bond method' to introduce a "phantom orbital" and an additional electron, a procedure which simplifies the treatment without changing the results.