Steer Ronald P
Department of Chemistry University of Saskatchewan Saskatoon, SK, S7N5C9, Canada.
Phys Chem Chem Phys. 2023 Sep 13;25(35):23384-23394. doi: 10.1039/d3cp03201a.
The few known reports and the likely prospects of finding new efficient routes to exciton fission from higher excited singlet states, S ( > 1), are reviewed. Aggregates of molecules that have large S-S electronic energy spacings and/or emit measurable "contra-Kasha" emission may offer further opportunities. Among these, electronically excited molecular systems that exhibit known efficient (T + T) triplet-triplet annihilation producing S could exhibit efficient singlet fission in aggregates when appropriately substituted to meet the necessary energy requirements. The potential problem of loss of triplet excitons 2T → T + S triplet-triplet annihilation following (S + S) singlet fission is addressed. Aggregates of substituted azulenes and aliphatic thiones and dithiones are particularly attractive and are discussed in detail.
本文综述了关于从较高激发单重态S（>1）实现激子裂变的新有效途径的少数已知报道及其可能前景。具有大的S-S电子能量间距和/或发射可测量的“反卡莎”发射的分子聚集体可能提供更多机会。其中，表现出已知的通过高效（T+T）三重态-三重态湮灭产生单重态的电子激发分子体系，在经过适当取代以满足必要的能量要求时，在聚集体中可能表现出高效的单重态裂变。文中还讨论了（S+S）单重态裂变后三重态激子损失2T→T+S的三重态-三重态湮灭这一潜在问题。取代薁以及脂肪族硫酮和二硫酮的聚集体尤其具有吸引力，并将进行详细讨论。
