Photocyclization of [2.2]Metacyclophane at 2537 Å

概要

論文の詳細を見る
The photochemical reaction of [2.2]metacyclophane at 2537 Å has been studied spectrophotometrically. Photocyclization took place to give 4,5,9,10-tetrahydropyrene not only in aerated but also in degassed solutions. The quantum yields for the reaction were independent of the irradiation time, concentration of starting material, light intensity, and addition of piperylene. However, the reaction quantum yields increased with temperature rise. The quantum yields in the aerated system were somewhat larger than those in the degassed system. Radiationless deactivation in S1(ππ*) was very efficient, whose quantum yield was assumed to be ∼0.99, judging from the small reaction quantum yield (less than 0.01) and the lack of fluorescence and phosphorescence. It is proposed that the photocyclization of the molecule originates from S1(ππ*) to give intermediate M which is subsequently convreted into the product or the starting material. Activation energies in these processes were estimated.
公益社団法人日本化学会の論文