Rigid Enhanced Electrochemiluminescence of 1,2,3-Triaryl Indenes as an Ultrasensitive Sensor for D 2 O in H 2 O.

The intriguing aggregation-induced emission has recently been applied in the electrochemiluminescence, called aggregation-induced electrochemiluminescence (AIE-ECL), which is conducive to solving the water insolubility and aggregation-caused quenching for most organic luminescence probes. However, AIE-ECL still has the problems of low luminous efficiency and limited practical application. In this work, we disclosed the AIE-ECL properties of 1,2,3-triaryl-substituted indenes containing rigid structures. Experimental and theoretical investigations demonstrated that such a rigid structure could significantly enhance the aromaticity and stability and thereby the luminescence performance of these indenes. Moreover, according to the finding of hydrogen/deuterium exchange for active hydrogen in indene under electrical excitation, ultrasensitive detection for D 2 O in H 2 O was realized by such an indene-based AIE-ECL system. Our research not only provided an attractive strategy to enhance the luminescence property for an AIE-active luminophore but also established a superior sensor toward D 2 O.