J. Terence Blaskovits, Clémence Corminboeuf, Marc H. Garner
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引用次数: 0
Abstract
Molecules where the lowest excited singlet state is lower in energy than the lowest triplet are highly promising for a number of organic materials applications as efficiency limitations stemming from spin statistics are overcome. All molecules known to possess such singlet–triplet inversions exhibit a pattern of spatially alternating but nonoverlapping HOMO and LUMO orbitals, meaning the lowest excited states are of a local character. Here, we demonstrate that derivatives of the bicyclic hydrocarbon calicene exhibit Hund’s rule violations in charge-transfer (CT) states between its rings. These CT states can be tuned with substituents, so that the first excited singlet and triplet state are energetically inverted. This provides a conceptual connection between the emerging fields of inverted gap molecules and existing molecular design rules for state-of-the-art thermally activated delayed fluorescence materials.
最低激发态单线态的能量低于最低激发态三线态的分子,由于克服了自旋统计带来的效率限制,因此在许多有机材料应用领域大有可为。所有已知具有这种单重-三重反转的分子都表现出空间交替但不重叠的 HOMO 和 LUMO 轨道模式,这意味着最低激发态具有局部性。在这里,我们证明了双环碳氢化合物钙钛矿的衍生物在其环间的电荷转移(CT)态中表现出违反亨德规则的现象。这些电荷转移(CT)态可通过取代基进行调整,从而使第一激发单线态和三线态发生能量倒置。这为新兴的反向间隙分子领域和最先进的热激活延迟荧光材料的现有分子设计规则提供了概念上的联系。
期刊介绍:
The Journal of Physical Chemistry (JPC) Letters is devoted to reporting new and original experimental and theoretical basic research of interest to physical chemists, biophysical chemists, chemical physicists, physicists, material scientists, and engineers. An important criterion for acceptance is that the paper reports a significant scientific advance and/or physical insight such that rapid publication is essential. Two issues of JPC Letters are published each month.