Approaching White-Light Emission from a Phosphorescent Trinuclear Gold(I) Cluster by Modulating Its Aggregation Behavior
Approaching White-Light Emission from a Phosphorescent Trinuclear Gold(I) Cluster by Modulating Its Aggregation Behavior
复制标题
通过调节磷光三核金 (I) 团簇的聚集行为来接近白光发射
DOI：
10.1002/anie.201308135
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发表时间：
2013-12-09
影响因子：
16.6
通讯作者：
Li, Dan
中科院分区：
文献类型：
--
作者：
Ni, Wen-Xiu;Li, Mian;Li, Dan
白光发光材料和器件的发展[1]在下一代固态照明技术中起着重要的作用。[2]在这个领域中，通常有两种类型的工作原理来实现白色光，或者来自多个协作发射器[3]，或者来自单个多功能发射器。[4]这两种情况都产生至少是白色光的互补色的双发射（例如，带蓝色的绿色和带红色的橙子）。单个多功能发射器类型上级多个协作发射器，因为它可以防止相位分离和颜色变化问题。[1]然而，设计和合成单分子，特别是磷光配位络合物，其在宽可见光谱范围内发射并表现出白色光，仍然是一个挑战。[5]Che [6]和Yam [7]的研究小组在发光PtII配合物方面取得了一些重大进展，他们利用了促进这些系统中宽带发射的单体-激基缔合物平衡。这种深入的研究已经保证了PtII络合物在单掺杂白色有机发光器件（WOLED）中的应用，这两个小组[8]和其他人也在推进。[9]根据PtII配合物的工作原理，要产生双发射带的白色光，必须满足两个结构前提：1）必须有一定的发色团官能团，以保证单体的发光效率; 2）所设计的分子需要具有小空间位阻的结构（例如PtII络合物的正方形平面构型[6，7]），以促进当单体彼此紧邻定位时激基缔合物的形成。金配合物在OLED开发中显示出了希望，不仅因为它们呈现出丰富的光化学，还因为它们具有低毒性和环境友好性。[10]然而，与广泛研究的PtII配合物不同，基于光致发光AuI配合物的WOLED的潜力被评价得少得多。在试图合成金白光发射材料的过程中，我们专注于我们和其他人感兴趣的三核d10 MI吡唑簇（M= Cu，Ag，Au）家族[11]。[12]其中，AuI类似物具有潜在的有用性质：它们具有形成由AuI··· AuI键连接的准分子的强烈倾向（亲金性[13]），这是由它们的刚性平面构型和线性配位模式支持的，并给出明亮和长寿命的磷光。[10]三核AuI吡唑配合物的受激基[12，14]受自聚集调节，通常在低能（LE）橙红色区域发射。然而，白色光的产生需要单体的高能（HE）蓝绿色区域的合作，这通常是缺乏在报道的MI吡唑簇。[11，12]在本文中，噻吩基团，其可以增加光吸收以促进发光，[15]被引入作为吡唑上的取代基，以增强单体的高能量发射。
The development of white-light-emitting materials and devices [1] plays an important role in the next-generation solidstate lighting technology.[2] In this field, there are generally two types of working principles to achieve white light, either from multiple cooperating emitters,[3] or from a single multifunctioning emitter.[4] Both cases generate at least dual emissions (eg bluish green and reddish orange) that are complementary colors of white light. The single multifunctioning emitter type is superior to the multiple cooperating emitters because it can prevent phase-separation and color variation problems.[1] However it remains a challenge to design and synthesize single molecules, especially phosphorescent coordination complexes, that emit across the broad visible spectrum and exhibit white light.[5] Some significant progress has been made for luminescent PtII complexes by the groups of Che [6] and Yam,[7] who took advantage of the monomer–excimer equilibrium that facilitates the broad band emissions in these systems. Such in-depth studies have warranted the application of PtII complexes in single-dopant white organic light-emitting devices (WOLEDs), advanced also by these two groups [8] and others.[9] Based on the working principle of PtII complexes, two structural prerequisites have to be fulfilled to generate white light from dual emission bands: 1) there should be a certain functional group acting as a chromophore to ensure the luminescent efficiency of the monomer; 2) the designed molecule requires a structure with little steric hindrance (eg the square-planar configuration of PtII complexes [6, 7]) to facilitate the formation of the excimer when the monomers are positioned in close proximity to each other. Gold complexes have shown promise in OLED developments, not only because they present rich photochemistry, but also because they have low-toxicity and are environmentally benign.[10] However, unlike the PtII complexes, which are widely investigated, the potential for WOLEDs based on photoluminescent AuI complexes has been much less evaluated.In an attempt to synthesize gold white-light emitting materials, we focus on a family of trinuclear d10 MI pyrazolate clusters (M= Cu, Ag, Au) that have been of interest to us [11] and others.[12] Among these, the AuI analogues have potentially useful properties: they have a strong tendency to form excimers linked by AuI··· AuI bonding (aurophilicity [13]), which is supported by their rigid planar configuration and linear coordination mode, and give bright and long-lived phosphorescence.[10] The excimers of trinuclear AuI pyrazolate complexes,[12, 14] regulated by self-aggregation, usually emit in the low-energy (LE) orange–red region. However, the generation of white light requires the cooperation of the high-energy (HE) blue–green region of the monomer, which is usually absent in reported MI pyrazolate clusters.[11, 12] Herein the thiophene group, which can increase light absorption to promote luminescence,[15] is introduced as a substituent on pyrazole, to enhance the high-energy emission of the monomer.