Reversible photoregulation of the electrical conductivity of spiropyran-doped polyaniline for information recording and nondestructive processing

Diarylethene derivatives with two chiral substituents (see Figure) undergo reversible diastereoselective photocyclization reactions in a bulk amorphous state. An enrichment of one of the diastereomers (25% d.e.) has been found to exist below the glass transition temperature. The diastereoselection clearly indicates that short distance regularity exists in the glassy state.