Nanostructured Multiporphyrin Dendrimers: Synthesis, Characterization and Their Spectroscopic Properties

A series of resorcinarene-PAMAM-porphyrin dendrimers was synthesized. The nanostructures were characterized by IR, H-1 and C-13 NMR, UV-vis absorption, electrospray ionization and MALDI-TOF mass spectrometry. The morphological properties were characterized by High-Resolution Transmission Electron Microscopy (HRTEM). The distance between the resorcinarene group and the porphyrin group was variable: two different lengths of the dendritic branches were synthesized, which were found to play an important role in influencing the fluorescence properties. It was also possible to observe by HRTEM microscopy that the dendrimers were nearly monodisperse, retained their size and their shape was roughly spherical. Experimental data confirmed that the PAMAM groups favored the intense emission and red shift of the maximum wavelength. It is possible that the fluorescence centers were perturbed by the inner influence between the PAMAM groups. These nanostructures could be used for the conversion of photoenergy.