4,5-Dimethylthio-4‘-[2-(9-anthryloxy)ethylthio]tetrathiafulvalene, a Highly Selective and Sensitive Chemiluminescence Probe for Singlet Oxygen

Abstract

4,5-Dimethylthio-4'-[2-(9-anthryloxy)ethylthio]tetrathiafulvalene has been designed and synthesized as a highly selective and sensitive chemiluminescence (CL) probe for singlet oxygen ((1)O(2)). The design strategy for the probe is directed by the idea of photoinduced electron-transfer process and carried out through the incorporation of electron-rich tetrathiafulvalene unit into a reactive luminophore of anthracene specific for (1)O(2). Upon reaction with reactive oxygen species (ROS), such as hydrogen peroxide, hypochlorite, superoxide, hydroxyl radical, or (1)O(2), the probe exhibits both strong CL response to and high selectivity for (1)O(2) only, rather than the other ROS. This remarkable CL property permits (1)O(2) to be distinguished easily from the other ROS and makes the probe possible to be used widely for (1)O(2) detection in many chemical and biological systems and even in light water (H(2)O) environments. This applicability has been demonstrated by monitoring the (1)O(2) generation in a metal-catalyzed decomposition system of tert-butyl hydroperoxide. Moreover, the CL reaction mechanism of the present system is also discussed, clearly confirming that the introduction of electron-rich tetrathiafulvalene into the 9-position of anthracene can greatly activate its reactivity toward (1)O(2).