title: Enhanced Triplet-Triplet Energy Transfer and Upconversion Fluorescence through Host-Guest Complexation.
abstract: Perylene-tethered pillar[5]arenes and C60-boron-dipyrromethene (BODIPY) dyads were synthesized acting as emitters and organic triplet photosensitizers, respectively, for the purpose of improving the efficiency of triplet-triplet annihilation upconversion (TTA-UC). The photophysical properties of the sensitizers (guests) and the emitters (hosts) were not greatly influenced by the chemical modifications except for a notable decrease in the fluorescence quantum yields of the perlyene emitters due to the high local concentration. The perylene-tethered pillar[5]arenes form stable 1:1 complexes with a nitrile-bearing C60-BODIPY dyad, showing association constants as high as 4.0 × 104M-1. Through host-guest complexation, the efficiencies of both triplet-triplet energy transfer and TTA were significantly enhanced, which overcompensated for the loss of the fluorescence quantum yield of the emitters (hosts). Thus, an improved TTA-UC efficiency of 3.2% was observed even at a diluted concentration of 6 × 10-5M, demonstrating for the first time the effectiveness of the supramolecular motif for enhancing TTA-UC without varying the inherent photophysical properties of sensitizers and emitters.
authors: Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry and State Key Laboratory of Biotherapy, West China Medical School, Sichuan University , 29 Wangjiang Road, Chengdu 610064, China.
authors: Chunying
authors: C
authors: Fan
authors: Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry and State Key Laboratory of Biotherapy, West China Medical School, Sichuan University , 29 Wangjiang Road, Chengdu 610064, China.|State Key Laboratory of Fine Chemicals, Dalian University of Technology , Dalian 116024, China.
authors: Wanhua
authors: W
authors: Wu
authors: Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry and State Key Laboratory of Biotherapy, West China Medical School, Sichuan University , 29 Wangjiang Road, Chengdu 610064, China.|Sino-British Materials Research Institute, College of Physical Science and Technology, Sichuan University , Chengdu 610064, China.
authors: Jason J
authors: JJ
authors: Chruma
authors: State Key Laboratory of Fine Chemicals, Dalian University of Technology , Dalian 116024, China.
authors: Jianzhang
authors: J
authors: Zhao
authors: Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry and State Key Laboratory of Biotherapy, West China Medical School, Sichuan University , 29 Wangjiang Road, Chengdu 610064, China.
authors: Cheng
authors: C
authors: Yang