CYCLIC FULGENATES - ENLARGEMENT OF QUANTUM YIELD OF COLORING REACTIONOF PHOTOCHROMIC FULGENATES

Four cyclic indolylfulgenates, derivatives of fulgenates with 1,4-buta ne-, 1,5-pentane-, and 1,10-decanediols and 1,2-bis(hydroxymethyl)benz ene, were synthesized and their photochromic properties were compared with those of dimethyl indolylfulgenate. The most notable feature of c yclic fulgenates with relatively short alkyl chains is that the colori ng quantum yield of UV-light irradiation is much larger than that of t he acyclic fulgenate and that of the cyclic fulgenate with a long alky l chain.