Twisted Intramolecular Charge Transfer and Aggregation-Induced Emission of BODIPY Derivatives

作者：Rongrong Hu, Erik Lager, Angélica Aguilar‐Aguilar, Jianzhao Liu, Jacky W. Y. Lam, Herman H. Y. Sung, Ian Duncan Williams, Yongchun Zhong, Kam Sing Wong, Eduardo Peña‐Cabrera, Ben Zhong Tang · 发表于：The Journal of Physical Chemistry C · 年份：2009 · DOI：10.1021/jp902962h · 被引用次数：1033 · 研究领域：Luminescence and Fluorescent Materials、Porphyrin and Phthalocyanine Chemistry、Molecular Sensors and Ion Detection

Boron dipyrromethene (BODIPY) derivatives 1 and 2 consisting of donor and acceptor units with dual photoresponses to solvent polarity and luminogen aggregation are developed through taking advantage of twisted intramolecular charge transfer (TICT) and aggregation-induced emission (AIE) processes. In nonpolar solvents, the locally excited (LE) states of the BODIPY luminogens emit intense green lights. Increasing solvent polarity brings the luminogens from the LE state to the TICT state, causing a large bathochromic shift in the emission color but a dramatic decrease in the emission efficiency. The red emission is greatly boosted by aggregate formation or AIE effect: addition of large amounts of water into the solutions of 1 and 2 in the polar solvents causes the luminogens to aggregate supramolecularly and to emit efficiently. The emission can be enhanced by increasing solvent viscosity and decreasing solution temperature, indicating that the AIE effect is caused by the restriction of the intramolecular rotations in the aggregates of the luminogens.