Brannan Alexander C, Cho Hwan-Hee, Reponen Antti-Pekka M, Linnolahti Mikko, Bochmann Manfred, Greenham Neil C, Romanov Alexander S
Department of Chemistry, The University of Manchester, Oxford Rd., Manchester, M13 9PL, UK.
Department of Physics, Cavendish Laboratory, Cambridge University, Cambridge, CB3 0HF, UK.
Adv Mater. 2024 Feb;36(5):e2306249. doi: 10.1002/adma.202306249. Epub 2023 Dec 5.
A series of carbene-gold-acetylide complexes [(BiCAAC)AuCC] C H (n = 1, Au1; n = 2, Au2; n = 3, Au3; BiCAAC = bicyclic(alkyl)(amino)carbene) have been synthesized in high yields. Compounds Au1-Au3 exhibit deep-blue to blue-green phosphorescence with good quantum yields up to 43% in all media. An increase of the (BiCAAC)Au moieties in gold complexes Au1-Au3 increases the extinction coefficients in the UV-vis spectra and stronger oscillator strength coefficients supported by theoretical calculations. The luminescence radiative rates decrease with an increase of the (BiCAAC)Au moieties. The time-dependent density functional theory study supports a charge-transfer nature of the phosphorescence due to the large (0.5-0.6 eV) energy gap between singlet excited (S ) and triplet excited (T ) states. Transient luminescence study reveals the presence of both nonstructured UV prompt-fluorescence and vibronically resolved long-lived phosphorescence 428 nm. Organic light-emitting diodes (OLED) are fabricated by physical vapor deposition with 2,8-bis(diphenylphosphoryl)dibenzo[b,d]furan (PPF) as a host material with complex Au1. The near-UV electroluminescence is observed at 405 nm with device efficiency of 1% while demonstrating OLED device lifetime LT up to 20 min at practical brightness of 10 nits, indicating a highly promising class of materials to develop stable UV-OLEDs.
已高产率合成了一系列卡宾-金-乙炔配合物[(BiCAAC)AuCC]C₆H₅（n = 1，Au1；n = 2，Au2；n = 3，Au3；BiCAAC = 双环（烷基）（氨基）卡宾）。化合物Au1 - Au3在所有介质中均呈现深蓝至蓝绿色磷光，量子产率高达43%。金配合物Au1 - Au3中(BiCAAC)Au部分的增加会提高紫外-可见光谱中的消光系数，并在理论计算的支持下具有更强的振子强度系数。发光辐射速率随(BiCAAC)Au部分的增加而降低。含时密度泛函理论研究表明，由于单重激发态（S₁）和三重激发态（T₁）之间存在较大的（0.5 - 0.6 eV）能隙，磷光具有电荷转移性质。瞬态发光研究揭示了在428 nm处同时存在无结构的紫外瞬态荧光和振动分辨的长寿命磷光。以2,8 - 双（二苯基磷酰基）二苯并[b,d]呋喃（PPF）为主体材料，与配合物Au1通过物理气相沉积法制备了有机发光二极管（OLED）。在405 nm处观察到近紫外电致发光，器件效率为1%，同时在实际亮度为10尼特时，OLED器件寿命LT高达20分钟，表明这是一类极具开发稳定紫外OLED潜力的材料。
