Room temperature phosphorescence (RTP) materials have become a hot topic in fields of organic light-emitting dioes, biological sensing and imaging. The present work reports firstly that 1,3,5-trifluoro-2,4,6-triiodobenzene (TITFB) can act as a simple pure organic NIR phosphor due to its novel function in promoting n-π∗ transition. Also, TITFB crystal has longer phosphorescence lifetime than other ordinary multiiodoluminophors and TITFB powder. Based on the TITFB crystal structure, σ-hole and π-hole capture mechanism of n-electron is proposed, i.e., the excited state energy is decreased and n-electrons are stabilized to cause slower radiative decay rate due to the restriction of σ-hole and π-hole bond. Both computational and experimental studies support the mechanism. The new electron-capture mode is more conducive to understanding pure organic ultralong lifetime RTP.

室温磷光（RTP）材料已成为有机发光二极管，生物传感和成像领域的热门话题。本工作首先报道了1,3,5-三氟-2,4,6-三碘代苯（TITFB）由于其促进n-π*跃迁的新功能而可以用作简单的纯有机NIR磷光体。而且，TITFB晶体具有比其他普通的多碘发光体和TITFB粉末更长的磷光寿命。基于TITFB晶体结构，提出了n电子的σ孔和π孔俘获机制，即受σ-的限制，降低了激发态能量，稳定了n电子，导致辐射衰变速率变慢。孔和π孔键。计算和实验研究均支持该机制。