| 초록 |
We have synthesized Er(III)-complexes based on π-extended anthracene ligands bearing G3-aryl-ether dendron ([G3-AnX]-CO2H), which retain different π-bridging systems, such as single(X= S), double(X= D) and triple(X= T) bonds. They have similar structures with a higher rotation barrier caused by a steric hindrance between π-extended phenyl group and anthracene. All Er(III)-encapsulated dendrimer complexes exhibit strong near infrared emission bands. The intensity of Er(III) ion emission is decreased as the following order: Er3+-[G3-AnD]3(terpy) ＞ Er3+-[G3-AnS]3(terpy) Er3+-[G3-AnT]3(terpy). It is due to the higher relative spectral overlap J value between the emission of ligand and the absorption of Er(III) ion in Er3+-[G3-AnD]3(terpy). Also, no detectable phosphorescence and no significant spectral dependence of the π-extended anthracene moieties on the solvent polarity support the energy transfer from their singlet state taking place in Er3+-[G3-AnX]3(terpy). |
