Porphyrin-cored dendrimers consisting of novel siloxane-poly (amido amine) dendron-like arms: Synthesis, characterization, and photophysical properties

Different generations of porphyrin-cored dendrimers consisting of novel siloxane- poly(amido amine) dendron-like arms have been synthesized via copper(I)-catalyzed Huisgen 1,3-dipolar cycloaddition reaction of azide-modified 5,10,15,20-tetrakis(4-hydroxyphenyl)-porphyrin with different generations of propargyl focal point novel siloxane-poly(amido amine) typed dendron (Si-PAMAM). The used different generations of Si-PAMAM were obtained by the “arm-first” strategy based on the Michael addition reaction and Amidation reaction, orderly. The structure of porphyrin dendrimers is established by 1 H NMR, 13 C NMR, MALDI-TOF-MS and FT-IR analysis. PP-Si-PAMAM-Dm (m   =   1, 2, and 3), not only gave strong fluorescence emission and the intensity increased significantly as the generation growing, but also showed a remarkable pH-responsive in fluorescence emission. These interesting properties indicate that synthesized porphyrin dendrimers may be able to act as pH-responsive probes suitable for biomedical imaging, diagnosis and treatment.