# Combining Functional Units to Design Organic Materials with Dynamic Room-Temperature Phosphorescence under Continuous Ultraviolet Irradiation

## TL;DR

This paper introduces new organic materials that show dynamic phosphorescence at room temperature under UV light, enabling new detection techniques for polymer properties.

## Contribution

A novel strategy for designing organic materials with dynamic room-temperature phosphorescence by combining functional units.

## Key findings

- TASO and TA2O molecules exhibit enhanced dynamic room-temperature phosphorescence under continuous UV irradiation.
- The developed materials show improved absorption and oxygen-sensitive phosphorescence properties.
- A new time-resolved detection technique for polymer phase separation was demonstrated using these materials.

## Abstract

Developing materials with dynamic room-temperature phosphorescence (RTP) properties is crucial for expanding the applications of organic light-emitting materials. In this study, we designed and synthesized two novel RTP molecules by combining functional units, incorporating the folded unit thianthrene into the classic luminescent cores thioxanthone or anthraquinone to construct TASO and TA2O. In this combination, the TA unit contributes to the enhancement of spin–orbit coupling (SOC), while the luminescent core governs the triplet energy level. After the strategic manipulation of SOC using the thianthrene unit, the target molecules exhibited a remarkable enhancement in RTP performance. This strategy led to the successful development of TASO and TA2O molecules with outstanding dynamic RTP properties when exposed to continuous ultraviolet irradiation, a result that can be ascribed to their efficient RTP, improved absorption ability, and oxygen-sensitive RTP properties. Leveraging the oxygen-mediated ultraviolet-radiation-induced RTP enhancement in TASO-doped polymer films, we developed a novel time-resolved detection technique for identifying phase separation in polymers with varying oxygen permeability. This research offers a promising approach for constructing materials with dynamic RTP properties.