COTTON-MOUTON CONSTANTS AND VALENCY OPTICAL SCHEME FOR SALTS OF PYRIDINE, QUINOLINE, AND ISOQUINOLINE

A tensor additive scheme has been devised for the optical polarizabilities of the cations of pyridine, quinoline, and isoquinoline. The additional excess charge in these species leads to a decrease in the vertical component of the optical polarizability while the mobility of the electron cloud in the plane of the aromatic ring is retained. This effect is greater in the N-methyl derivatives than in the protonated forms.