Tuning Emission Color and Efficiency of 1,2,5-Triaryl-3,4-cycloalka[c]arsoles

Abstract

Abstract A variety of 1,2,5-triaryl-3,4-cycloalka[c]arsoles were synthesized in this study to control emission color and efficiency. The torsion between the arsole center and the aryl groups at the 2,5-positions was dependent on the size of the fused cycloalkane, resulting in different absorption maxima. In addition, structural relaxation was affected by the fused cycloalkane, which changed the emission color and efficiency. Notably, the cyclopentane-fused arsole showed aggregation-caused quenching (ACQ) in the solid state, while cyclohexane and cycloheptane offered aggregation-induced emission enhancement (AIEE). This trend was also seen in heterocycle-fused arsoles; five- and six-membered rings offered ACQ and AIEE, respectively. The p-(dimethylamino)phenyl and p-(dimesitylboryl)phenyl groups at the 2,5-positions exhibited red-shifted emission owing to the charge transfer character, and they could detect ions such as protons and fluoride anions, respectively.