The photophysical properties of the hydrogen bond complexes consisting of low-barrier hydrogen bond (LBHB) depend on their environmental condition. However, the stimuli responsive materials based on LBHB are still a challenging problem. Here, we report a novel material system which has high color response to CO₂ based on the position changes of the proton between the two heavy atoms in the low barrier hydrogen bond. Perylene diimide radical anion/branched polyethyleneimine hydrogen bonding complex (TFPDI-b-PEI) linked by low-barrier hydrogen bond ([O₁-----H₁---N₁]^-1) is obtained and it shows the maximum absorption of 789 nm. Meanwhile, the maximum absorption of TFPDI-b-PEI appears at 561 nm with purple when CO₂ is adsorbed in the branched polyethyleneimine. In essence, the geometry of LBHB in TFPDI-b-PEI can switch between two types of hydrogen bond ([O₁----H₁----N₁]^-1 and [O₁-----H₁---N₁]^-1) via adjusting the interaction between the surrounding molecule and amine groups in LBHB by interaction of CO₂ with TFPDI-b-PEI. Further the TFPDI-b-PEI shows excellent color switching and colorimetric sensing performance for CO₂ aqueous solution and its gas based on this hydrogen bond dynamic characteristic.

由低势垒氢键 (LBHB) 组成的氢键配合物的光物理性质取决于其环境条件。然而，基于LBHB的刺激响应材料仍然是一个具有挑战性的问题。在这里，我们报告了一种基于低势垒氢键中两个重原子之间质子位置变化的对CO ₂具有高颜色响应的新型材料系统。得到了由低势垒氢键（[O ₁ -----H ₁ ---N ₁ ] ^-1）连接的苝二亚胺自由基阴离子/支化聚乙烯亚胺氢键配合物（TFPDI-b-PEI），它显示了最大吸收 789  nm。同时，TFPDI-b-PEI 的最大吸收出现在 561 _{当CO 2}吸附在支化聚乙烯亚胺中时，nm带有紫色。本质上，TFPDI-b-PEI 中 LBHB 的几何结构可以在两种类型的氢键（[O ₁ ----H ₁ ----N ₁ ] ^-1和 [O ₁ -----H ₁ ---N ₁ ] ^{-1 ) 通过CO} ₂与TFPDI-b-PEI的相互作用来调节LBHB中周围分子与胺基之间的相互作用。此外，基于这种氢键动态特性，TFPDI-b-PEI 对 CO _{2水溶液及其气体表现出优异的颜色转换和比色传感性能。}