LASER PHOTOLYSIS OF NAPHTHOQUINONE DIAZIDE IN CYCLOHEXANE - 2-LASER CHEMISTRY

The laser photochemistry of 1,2-naphthoquinone-diazide-(2)-5-sulfonic acid phenylester in cyclohexane has been investigated. The photolysis experiments have been done using a KrF laser pulse (generation pulse) and a nitrogen laser pulse (transformation pulse) with various time de lay from 40 ns up to 1 s. At a time delay between the two laser pulses in the mus-region, the formation of indene and cyclohexyl-indene deri vatives has been observed, additional to the corresponding indenecarbo xylic acid. The laserspecific formation of these compounds is the resu lt of the electronic excitation of the intermediately formed ketene an d its reaction by decarbonylation. The time delay for getting a high y ield of the indene and the cyclohexyl-indene derivatives correlates cl osely with the rise time and the life time of the ketene.