Highly Sensitive Thianthrene Covalent Trimer Room‐Temperature Phosphorescent Materials for Low‐Concentration Oxygen Detection

Oxygen is ubiquitous and vital to life, industry, and environmental safety, so accurate and reliable oxygen sensing and detection is of great significance, especially for oxygen in the low concentration range. Herein, two pure organic metal‐free room‐temperature phosphorescence (RTP) materials were developed using a covalent trimerization strategy of thianthrene (TA), which exhibit high oxygen sensitivity and fluorescence‐RTP separated dual emission due to the moderate spin–orbit coupling (SOC). Compared with traditional metal‐organic complexes, the oxygen sensitivity of RTP is improved by about two orders of magnitude, especially facilitating accurate quantitative detection of low concentration oxygen. Leveraging oxygen quenching‐induced changes in emission color and intensity, coupled with computer‐assisted image processing, a simple oxygen monitoring device was established to realize real‐time and accurate detection of low‐concentration oxygen, promoting the industrial practical application in many related fields.