Organic luminogens with room temperature phosphorescence (RTP) have been paid great attention and developed rapidly for their wide application values. Until now, the internal mechanism and source of phosphorescence are still obscure, especially for the relationship between molecular dimer and RTP emission. Hence, we designed and synthesized eight phenothiazine 5,5-dioxide derivatives to directly reveal how the monomer and dimer in packing affect the RTP behavior. Dimers with strong π-π stacking (θ < 20.66°; d < 3.86 Å) lead to pure triplet excimer emission, while those with weak π-π stacking (27.02°< θ < 40.64°; 3.84 Å < d < 4.41 Å) contribute to dual RTP emissions of both monomer and triplet excimer. The valuable information of this work would promote the further development of this research field, as well as others in aggregate.

具有室温磷光(RTP)的有机发光材料因其广泛的应用价值而受到了广泛的关注并得到了迅速的发展。直到现在，磷光的内部机制和来源仍然不清楚，尤其是分子二聚体与RTP发射之间的关系。因此，我们设计并合成了八种吩噻嗪 5,5-二氧化物衍生物，以直接揭示包装中的单体和二聚体如何影响 RTP 行为。具有强 π-π 堆积 ( θ  < 20.66°; d  < 3.86 Å) 的二聚体导致纯三重态准分子发射，而具有弱 π-π 堆积 (27.02°<  θ  < 40.64°; 3.84 Å <  d ) 的二聚体 < 4.41 Å) 有助于单体和三重态准分子的双重 RTP 排放。这项工作的宝贵信息将促进该研究领域以及其他领域的进一步发展。