Abstract
Photoresponsive dendrimer with multiple chromophores is an interesting subject of research due to its unusual photophysical and photochemical properties based on interactions between the chromophores. In our previous work, we have synthesized poly(benzyl ether) stilbene dendrimers with no surface functional groups and those tethering one ester surface functional group on the para position of the dendron and have reported that their fluorescence properties as well as their photoisomerization behavior is affected by interactions between the stilbene core and dendrons. In this work, we have synthesized new poly(benzyl ether) stilbene dendrimers bearing two ester surface functional groups on the meta position of the dendron. Through optical spectroscopic measurements, we have investigated the photophysical and photochemical properties of the dendrimers and revealed that a unique isomerization mechanism, in which photoisomerization of the stilbene core is induced by triplet formation via intramolecular exciplex formation between the core and dendrons, may play an important role. The extent of quenching of the excited singlet state of the stilbene core by the surrounding dendrons depended on the number of ester groups and the generation of dendrimers.
