One-Dimensional Cu(I) coordination polymers with multi-stimuli-responsive luminescence

Luminescent coordination polymers (CPs) with one-dimensional (1D) closely-packed structures usually display poor performances in stimuli-responsive luminescence due to the low porosity and high rigidity. Here, we reported a multi-stimuli-responsive 1D luminescent [Cu2I2]-cluster-based CP (CuIP-OPY) with piezochromic, thermochromic and oxygen sensing properties. Attributing to the flexibility of the OPY ligand, which twists under external forces and heating, respectively, CuIP-OPY shows obvious piezochromic and thermochromic luminescence. Moreover, although its porosity is only 1.1%, oxygen can still quench its luminescence intensity by 57.53%. To further confirm the related mechanism, we also synthesized a [Cu2Cl2]-cluster-based CP with similar structure, namely CuClP-OPY, that displays higher rigidity, and compared the differences between these two CuXP-OPY (X = I, Cl) in the multi-stimuli-responsive behavior.