We report the design, synthesis, and spectroscopic characterization of polyphenylene-type polymers that can be used to sensitize europium complexes. Although benzophenone is widely studied and characterized, polybenzophenones have not been widely used in photophysical studies. The properties of poly(4'-methyl-2,4-benzophenone) (MB), poly(4'-methyl-2,5-benzophenone) (PB) and poly[2,2'-bipyridine-5,5'-diyl(2,5-didecoxy-1,4-phenylene)] (PBP) are described in this paper. All three polymers have backbones that are similar to polyphenylene. PBP has a bipyridine unit that alternates with a phenyl ring. Benzophenone rings are polymerized with para or meta linkages in PB and MB, respectively. All three polymers have similar emission maxima at 430 nm, but PBP has a higher quantum efficiency of emission. The polymers studied in this paper proved to be of lower energy than what is needed to sensitize many europium complexes. In almost all of the lanthanide complexes the ligands played a major role in the emission properties. This was elaborated in studies done previously. Europium chelates of the two different ligands: di(2-thienoyl)methane (DTM) and di(2-naphthoyl)methane (DNM) proved to be of comparable energies with the polymers studied. Results showed that energy transfer did occur between the polymers and the europium chelates, but the energy transfer was not 100% because residual emission from the polymers was detected.

A series of photon harvesting lanthanide complexes have been synthesized by chelating dendritic â-diketone ligands to Eu+3. The ligands are modified benzoyltrifluoroacetone units (BTFA) with poly(aryl ether) dendron attachments. These ligands impose a very large asymmetric nature to the first coordination sphere of europium compared to previous dendritic compounds. These complexes exhibit europium emission with no residual emission from the ligands as the dendritic subunits increase from G-0 to G-3. This is due to both antenna and site isolation effects. These complexes mimic light harvesting organisms seen in Nature. When these intensities are compared throughout the series, an increase in intensity is seen where [(G2)BTFA]3Eu is the brightest, with [(G3)BTFA]3Eu being less intense than the G-2 complex. However, the lifetime data indicates that the G-3 complex is the longest lived species.