XAFS studies of Tb or Eu cored dendrimer complexes with various propertiesof luminescence

We studied the extended X-ray absorption fine structure (EXAFS) of Tb or Eu L3-edge of Tb(III) or Eu(III)-cored complexes of different luminescence to which different poly( benzyl ether) dendrons coordinated. The complexes we re prepared via a ligand exchange reaction of dendritic carboxylic acid and acetate. Results show that (a) the Eu complex of the first generation of t he 3,4- or 3,5-dibenzyloxyphenyl type had a coordination structure differen t from that of the 2,4-dibenzyloxyphenyl type; (b) the Eu complex of the fi rst generation of 3,5-dinaphthylmethoxyphenyl type had a Eu-O coordination number higher than the total number of oxygen atoms in the carboxylate grou ps; (c) the Tb complex of the bulky fourth generation had a Tb-O coordinati on number higher than that of the first generation. These results show that the different poly( benzyl ether) dendrons cause the different coordinatio n, which might differently influence the luminescence properties of the com plexes.