A Novel Ratiometric Oxygen Sensor Based On a Sextuple Hydrogen-Bonding Self-Assembly Molecular Heterodimer

A novel sextuple hydrogen-bonding (HB) self-assembly molecular heterodimer bearing an iridium complex as the indicator dye and two carbazoles as the reference dye, namely 6HB-Irbt-Cz, was synthesized, and its molecular structure was confirmed by H-1 NMR, (CNMR)-C-13, TOF-MS and 2D NMR. Because of the inefficient energy transfer process between the carbazole and iridium complex units, 6HB-Irbt-Cz exhibits distinct fluorescence/phosphorescence dual emission in neat film state. More importantly, the neat film sample of 6HB-Irbt-Cz could display linear ratiometric optical response toward oxygen in the full oxygen concentration range from 0 to 100 vol%, together with good stability, reversibility and rapid response-recovery times. Note that this represents the first discovery of neat-film-based oxygen sensor capable of showing strictly linear ratiometric Stern-Volmer behavior in the oxygen concentration of 0-100 vol%.