Phenylacetylene Dendrimers Containing a Fluorene Core: Synthesis and Spectroscopic Studies

Phenylacetylene dendrimers 9-11 containing fluorene as the core with a larger HOMO-LUMO energy gap were synthesized and characterized. Their structure and properties were studied by UV, FL, H-1 NMR, MS etc. These novel phenylacetylene dendrimers exhibit unique photophysical properties. They exist a new absorption band around 340 nm whose molar coefficient decreases with increasing generation. The band-gaps of 9-11 are 3.54, 3.43 and 3.02 respectively. The fluorescence quantum yield of 10 is as high as 0.61.