Novel poly(aryl ether) type dendrimers having photo-cross-linking and thermal de-cross-linking properties were synthesized by a convergent method. A protected A(2)B monomer, 1-allyloxy-3,5-bis(bromomethyl)benzene, was newly prepared for the dendrimer synthesis. Palladium-catalyzed deprotection of an allyl group proceeded in high yields. The films of dendrimers containing a photoacid generator (PAG) became insoluble in solvents on irradiation. The irradiated films became soluble in solvents after baking at 120-200 degrees C. The insolubilization and redissolution profiles were strongly affected by irradiation and baking conditions and the generation of the dendrimers. A reaction pathway was studied by TGA and DTA analysis and FT-IR spectroscopy. (C) 2010 Elsevier Ltd. All rights reserved.