Highly Selective Detection of H<sup>+</sup> and OH<sup>–</sup> with a Single-Emissive Iridium(III) Complex: A Mild Approach to Conversion of Non-AIEE to AIEE Complex AlamParvej KaurGurpreet SarmahAmrit RoyRam Kinkar ChoudhuryAngshuman Roy LaskarInamur Rahaman 2015 A greenish-blue emissive bis-cyclometalated iridium­(III) complex with octahedral geometry was synthesized in a convenient route where a bulky substituted ligand, <i>N</i><sup>1</sup><b>-</b>tritylethane-1,2-diamine ligand (trityl-based rotating unit) (<b>L</b><sub><b>1</b></sub>), was coordinated to iridium­(III) in nonchelating mode, [Ir­(F<sub>2</sub>ppy)<sub>2</sub>(L<sub>1</sub>)­(Cl)], [F<sub>2</sub>ppy = 2-(2′,4′-difluoro)­phenylpyridine; <b>L</b><sub><b>1</b></sub> = <i>N</i><sup>1</sup>-tritylethane-1,2-diamine], <b>1</b>. The purpose of introducing a rotor in <b>1</b> was anticipated to initiate aggregation-induced emission (AIE) activity in it. The presence of a secondary amine in <b>L</b><sub><b>1</b></sub> has attributed to <b>1</b> the ability to sense acids. The mechanism of this change in <b>1</b> under acidic medium was explored. A bright yellow emissive complex was formed on exposing <b>1</b> to hydroxide ion, which was isolated, characterized, and identified as a new aggregation-induced enhanced emission (AIEE) active complex. The detection limit of hydroxide ion was determined to 126 nM. Ground- and excited-state properties of <b>1</b> were investigated using DFT- and TD-DFT-based calculations, and several important aspects of the experimental facts were validated.