Abstract: The microenvironment of carboxylic acid terminated dendrimers (Gn, n=1-4) was studied by using pyrene and anthracene as probes. The results of fluorescence spectra of pyrene indicated that dendrimers G1-G3 adopted an open structure, and G4 took a more close spherical shape which showed better encapsulation capability. The results of fluorescence spectra of (9-anthrymethyl) trimethylammonium(An) in G2 potassiumaqueous solution indicated that G2 could encapsulate more than two An molecules, and the hydrophobic anthracene moiety and the hydrophilic cation portion of An encapsulated within G2 were located in the interior and the periphery of the dendrimer, respectively.

Key words: Dendrimer, Microenvironment polarity, Fluorescence, Pyrene, Anthracene