A Cu I ‐Phosphonotriazolate Coordination Polymer Based on [Cu I 4 Cl] Cluster for Fluorescent Sensing of O 2

A novel cuprous coordination polymer built of [Cu4ICl] cluster and 4-(1,2,4-triazol-4-yl)phenylphosphonate acid (H2ptz) ligand has been hydrothermally synthesized, in which the CuI is in-situ generated by the reduction reaction from CuII precursors. This compound shows a green fluorescent emission with a maximum peak at 510 nm under N2 flow in solid state, which can be turned off by 21 % O2 flow in minutes. Interestingly, it can be turned on again by switching to N2 flow. A possible mechanism has also been proposed.