Zhao Jianjian, Liu Yaqing, Hao Aiyou, Xing Pengyao
School of Chemistry and Chemical Engineering , Shandong University , Jinan 250100 , People's Republic of China.
ACS Nano. 2020 Feb 25;14(2):2522-2532. doi: 10.1021/acsnano.0c00352. Epub 2020 Feb 10.
The emergence, amplification, and manipulation of chiroptical activity in self-assembled nanostructures, including circularly polarized absorbance and luminescence (CPL), remain considerable challenges. Here, we report the high-throughput synthesis of nanostructures with finely tailored chiroptical activities. Two fully π-conjugated benzimidazoles formed H-bonded complexes with natural hydroxyl acids (tartaric acid and mandelic acid), which self-assembled into diversified macroscopically chiral nanostructures. Synergistic coassembly allows for the emergence of Cotton effects and CPL with high dissymmetry -factors ( up to 8 × 10, up to 3 × 10). The tartaric acid coassembled system exhibits enantiomer-independent left-handed CPL, which transforms into a cooperative ternary coassembly appended with enantiomer-resolved CPL with extended emission wavelength upon selective transition metal ion chelation. This H-boned coassembly system provides a vast number of chiral nanostructures with flexibly tuned Cotton effects and CPL, which also behaves as a selective chiroptical sensor to metal ions.
在自组装纳米结构中实现手性光学活性（包括圆偏振吸收和发光，即CPL）的产生、放大和调控仍然是巨大的挑战。在此，我们报道了具有精细调控手性光学活性的纳米结构的高通量合成。两种完全π共轭的苯并咪唑与天然羟基酸（酒石酸和扁桃酸）形成氢键复合物，它们自组装成多种宏观手性纳米结构。协同共组装使得能够出现具有高不对称因子（高达8×10，高达3×10）的科顿效应和CPL。酒石酸共组装体系表现出与对映体无关的左旋CPL，在选择性过渡金属离子螯合后，它转变为具有对映体分辨CPL且发射波长延长的协同三元共组装。这种氢键共组装体系提供了大量具有灵活调控的科顿效应和CPL的手性纳米结构，其还可作为金属离子选择性手性光学传感器。
