本工作以羧基为末端基团的芳醚树枝形聚合物Gn(n=1—4)和核心为十二烷基链的聚酰胺-胺树枝形聚合物PGm(m=1—3)作为光化学微反应器,研究了1-苯基-3-对甲苯基丙酮在水溶液中的α-光解反应,并计算了笼效应.研究结果表明,芳醚树枝形聚合物Gn的笼效应随代数增加而增大,高代数树枝形聚合物表现出对底物分子更强的限制性作用,增加树枝形聚合物的浓度可以提高笼效应;聚酰胺-胺树枝形聚合物PGm对CH3-DBK的限制作用远低于芳醚树枝形聚合物Gn.
The α-cleavage photoreactionof 1-phenyl-3-p-tolyl-propan-2-one(CH3-DBK) hasbeen conductedin aqueoussolutions of water-soluble poly(aryl ether) dendrimers Gn(n=1-4) and PAMAM dendrimers PGm(m=1-3).The product distributionreveals that dendrimers can provide a more constrained microenvironment than the homogenous solutions.The cage effect increases with the generation of Gn,indicative of a better confined microenvironment of higher generation Gn.The cage effect can also be enhanced by increasing the concentration of dendrimer.PGm(m=1-3) have much less constrained microenvironment,consequently exhibit low cage effect.