Oxygen sensing behavior modulation of tetranuclear copper iodide hybrid materials using ligand engineering

Copper iodide hybrid materials (CIHMs) are receiving great attention as promising luminescent materials. Their structural diversity can be enriched by design and selection of organic ligands, associated with corresponding photophysical properties. However, the role of ligands in modulating sensing performance of CIHMs stays rarely revealed. Here, we demonstrate the O2 sensing capability of four tetranuclear CIHMs and reveal the impact of ligands on their different triplet quenching process. Oxygen sensing films were prepared using the selected CIHMs. The study results reveal their oxygen sensing behaviors with wide linear photoluminescence (PL) responses in the range from 0% to 100% for gaseous oxygen, and the corresponding PL quenching ratios of 12.14, 11.30, 2.90 and 2.26 (0–100% O2), respectively. In addition, all the CIHMs showed rapid and reversible response to oxygen within 10 s. Through investigating the time-resolved luminescence spectra, 1H NMR and corresponding crystal structures of the CIHMs in N2 and O2 environments, we highlight that specific crystal stacking patterns caused by different ligands play a major role in their distinct oxygen sensing behaviors. It indicates that the sensing performance of the CIHMs can be regulated through functionalization of the ligands which inspires new insights into their more extensive application.