Nguyen Yennie H, Dang Vinh Q, Soares João Vitor, Wu Judy I, Teets Thomas S
Department of Chemistry, University of Houston 3585 Cullen Blvd. Room 112 Houston TX 77204-5003 USA
Chem Sci. 2023 Apr 17;14(18):4857-4862. doi: 10.1039/d3sc00712j. eCollection 2023 May 10.
The lack of efficient and robust deep-blue phosphorescent metal complexes remains a significant challenge in the context of electroluminescent color displays. The emissive triplet states of blue phosphors are deactivated by low-lying metal-centered (MC) states, which can be ameliorated by increasing the σ-donating ability of the supporting ligands. Here we unveil a synthetic strategy to access blue-phosphorescent complexes with two supporting acyclic diaminocarbenes (ADCs), known to be even stronger σ-donors than N-heterocyclic carbenes (NHCs). This new class of platinum complexes has excellent photoluminescence quantum yields, with four of six complexes affording deep-blue emission. Experimental and computational analyses are consistent with a pronounced destabilization of the MC states by the ADCs.
在电致发光彩色显示器的背景下，缺乏高效且稳定的深蓝色磷光金属配合物仍然是一个重大挑战。蓝色磷光体的发射三重态会被低能级的金属中心（MC）态淬灭，而通过提高配位配体的σ供电子能力可以改善这种情况。在此，我们揭示了一种合成策略，可用于制备具有两个配位无环二氨基卡宾（ADC）的蓝色磷光配合物，已知ADC是比N-杂环卡宾（NHC）更强的σ供体。这类新型铂配合物具有优异的光致发光量子产率，六个配合物中有四个能发出深蓝色光。实验和计算分析均表明，ADC会使MC态明显失稳。
