PHOTOCHROMISM OF N-SALICYLIDENEANILINE SINGLE-CRYSTAL

Photochromic and thermochromic properties in a large single crystal of N-salicylideneaniline are studied. The electric transition dipoles of the enol and trans-keto forms are nearly in the direction of the b ax is of the crystal. The activation energy of photo-induced transformati on from the enol to trans-keto form is estimated to be 24 meV and from the trans-keto to enol form to be 17 meV, and that of thermal transfo rmation from the trans-keto to enol form to be 200 meV.