Eyyathiyil Jusaina, Ghosh Subhajit, Cheran Arunima, Geremia Silvano, Kumar Jatish, Hickey Neal, Thilagar Pakkirisamy
Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bengaluru, Karnataka, India.
Department of Chemistry, Indian Institute of Science Education and Research, Tirupati, Andhra Pradesh, India.
Commun Chem. 2025 Apr 25;8(1):126. doi: 10.1038/s42004-025-01529-8.
Long-lived triplet exciton harvesting materials are of immense interest for applications in bioimaging, optoelectronics, anticounterfeiting, and sensing. However, achieving persistent room-temperature phosphorescence (pRTP) in metal-free systems remains a significant challenge. Herein, we present purely organic axially chiral aminoboranes (R/S-(BN)₂) with enhanced pRTP properties and circularly polarized luminescence (CPL). By introducing axial chirality, the dual-core (R/S-(BN)₂) system achieves steric-hindrance-caused rigidity, which restricts molecular motions, leading to superior phosphorescence properties. Notably, R-(BN)₂ demonstrates a phosphorescence quantum yield (Φ) of 9.2% (S-(BN)₂ : Φ = 8.7%) and an extended lifetime of 0.9 sec at room temperature, significantly outperforming its mono-core counterpart (BN)₁ (Φ = 3.0% and τ = 0.6 s). Theoretical analysis corroborates the observed improvements, revealing the synergistic role of borylation and axial chirality in stabilizing triplet states. Furthermore, the axially chiral aminoboranes exhibited CPL in dichloromethane solutions with a dissymmetry factor of ~10. These findings highlight the potential of axially chiral frameworks in designing efficient metal-free pRTP materials, as demonstrated in the security writing application, further paving the way for their use in bioimaging, anti-counterfeiting technologies, and next-generation organic electronics.
长寿命三线态激子收集材料在生物成像、光电子学、防伪和传感等应用中具有极大的吸引力。然而，在无金属体系中实现持久室温磷光（pRTP）仍然是一项重大挑战。在此，我们展示了具有增强的pRTP特性和圆偏振发光（CPL）的纯有机轴向手性氨基硼烷（R/S-(BN)₂）。通过引入轴向手性，双核（R/S-(BN)₂）体系实现了空间位阻导致的刚性，这限制了分子运动，从而产生了优异的磷光性能。值得注意的是，R-(BN)₂在室温下的磷光量子产率（Φ）为9.2%（S-(BN)₂：Φ = 8.7%），寿命延长至0.9秒，显著优于其单核对应物（BN）₁（Φ = 3.0%，τ = 0.6秒）。理论分析证实了观察到的改进，揭示了硼化和轴向手性在稳定三线态中的协同作用。此外，轴向手性氨基硼烷在二氯甲烷溶液中表现出CPL，不对称因子约为10。这些发现突出了轴向手性框架在设计高效无金属pRTP材料方面的潜力，如在安全书写应用中所示，进一步为其在生物成像、防伪技术和下一代有机电子学中的应用铺平了道路。
