Tani Yosuke, Oshima Yuya, Okada Rika, Fujimura Jun, Miyazaki Yuji, Nakano Motohiro, Urakawa Osamu, Inoue Tadashi, Ehara Takumi, Miyata Kiyoshi, Onda Ken, Ogawa Takuji
Department of Chemistry, Graduate School of Science, Osaka University Toyonaka Osaka 560-0043 Japan.
Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives (ICS-OTRI), Osaka University Suita Osaka 565-0871 Japan.
Chem Sci. 2025 Aug 7. doi: 10.1039/d5sc03768a.
Liquid is the most flexible state of condensed matter and shows promise as a functional soft material. However, these same characteristics make it challenging to achieve efficient room-temperature phosphorescence (RTP) from metal-free organic molecular liquids. Herein, we report efficient RTP from liquefied thienyl diketones bearing one or two dimethyloctylsilyl (DMOS) substituents. These solvent-free liquids exhibit high RTP quantum yields up to 5.6% in air and 25.6% under Ar due to their large RTP rate constant exceeding 5000 s. Both liquids undergo excited-state conformational changes and afford monomer RTP, exhibiting essentially the same narrowband spectra as in solution. Moreover, introducing two DMOS substituents sufficiently suppresses aggregation-caused quenching of the molecularly emissive phosphors, illustrating a design principle for RTP-active liquid materials.
液体是凝聚态物质中最具柔韧性的状态，有望成为一种功能性软材料。然而，正是这些相同的特性使得从无金属有机分子液体中实现高效室温磷光（RTP）具有挑战性。在此，我们报道了带有一个或两个二甲基辛基硅烷基（DMOS）取代基的液化噻吩二酮的高效RTP。这些无溶剂液体在空气中的RTP量子产率高达5.6%，在氩气下为25.6%，这是由于它们的RTP速率常数很大，超过了5000 s⁻¹。这两种液体都经历激发态构象变化并产生单体RTP，呈现出与溶液中基本相同的窄带光谱。此外，引入两个DMOS取代基充分抑制了分子发射磷光体的聚集导致的猝灭，阐明了RTP活性液体材料的设计原理。
