Laboratorium für Organische Chemie, ETH Zürich, Hönggerberg, HCI, 8093 Zürich, Switzerland.
Chemistry. 2010 Nov 8;16(42):12590-602. doi: 10.1002/chem.201001625.
A series of borondipyrromethane (BODIPY)-dye-labeled resorcin[4]arene cavitands 1-4 with different lengths of oligo(phenylene-ethynylene) spacers between the dyes and the macrocyclic rim has been synthesized. Their switching behavior from the "vase" to "kite" conformations in bulk solution was examined by both variable-temperature (VT) NMR and fluorescence spectroscopy. Both VT-NMR and VT fluorescence resonance energy transfer (FRET) experiments showed that cavitands 1-4 undergo vase-to-kite switching at low temperatures. Acid-triggered switching to the kite conformation was observed by fluorescence spectroscopy. Quantitative evaluation of the FRET data led to the determination of the Förster radius R(0)=37 Å for the BODIPY-dye FRET pair and an average cavitand opening angle α=16° in the vase conformation.
一系列的硼二吡咯甲烷（BODIPY）-染料标记的间苯二酚[4]芳烃穴醚 1-4 具有不同长度的寡聚（苯乙炔）间隔物在染料和大环边缘之间。通过变温（VT）NMR 和荧光光谱法研究了它们在本体溶液中从“花瓶”到“风筝”构象的开关行为。VT-NMR 和 VT 荧光共振能量转移（FRET）实验均表明，穴醚 1-4 在低温下发生花瓶到风筝的构象转变。荧光光谱法观察到酸触发的风筝构象的开关。FRET 数据的定量评估导致确定 BODIPY-染料 FRET 对的Förster 半径 R(0)=37 Å，以及在花瓶构象中平均穴醚开口角度α=16°。
