Novel synthesis of surface-block dendrimer using [4+4] photocycloaddition of anthryl dendrons

Novel surface-block dendrimer was synthesized via a divergent/convergent approach using [4+4] photocycloaddition of two different anthracenes bearing a newly designed dendritic substituent, of which terminal groups are long alkyl chains for one hemisphere and oligo(ethylene oxide) chains for the other hemisphere. A solution of the two different anthryl dendrons was irradiated with a high-pressure mercury lamp to afford a hetero-dimer, which consists of the two different dendrons. The surface-block dendrimer was isolated by the use of size exclusion chromatography (SEC) and well characterized by NMR spectrum, SEC, and MALDI-TOF-Mass spectrum. Furthermore, this paper describes a ratio of the photoproducts (the hetero-dimer and two homo-dimers) that were obtained from the photocycloaddition reactions carried out in neat and an emulsion condition, along with the solution.