Is a High Photoluminescence Quantum Yield Good Enough for OLEDs? Can Luminescence Rigidochromism Be Manifest in the Solid State? an Optoelectronic Device Screening Case Study for Diphosphine/Pyrazolate Copper(I) Complexes
Is a High Photoluminescence Quantum Yield Good Enough for OLEDs? Can Luminescence Rigidochromism Be Manifest in the Solid State? an Optoelectronic Device Screening Case Study for Diphosphine/Pyrazolate Copper(I) Complexes
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DOI：
10.1080/02603594.2019.1701448
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发表时间：
2020-01
影响因子：
5.4
通讯作者：
M. Omary;John J. Determan;Chammi S. Palehepitiya Gamage;P. Sinha;Shan Li;Monika R. Patterson;Vladimir N.
中科院分区：
文献类型：
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作者：
M. Omary;John J. Determan;Chammi S. Palehepitiya Gamage;P. Sinha;Shan Li;Monika R. Patterson;Vladimir N.
摘要本文提供了一个新的传统的第四个表现形式，其中无机化学评论的编辑希望以身作则，我们开始发表原创的研究内容，尽管如此，保留杂志的身份作为一个利基的批判性讨论当代文献在无机化学。(For第一、二、三种表现，见：a）Otten，B。M.; Melancon，K. M.;奥马里，M. A.“所有闪光的不是黄金：d10金属中心的双金属络合物中共价与亲金属键合的计算研究-在他去世10周年之际向Al Cotton致敬，”评论Inorg. Chem. 2018，38，1-35; B）Yaseen，W. K.的; Sanders，S. F.地;阿尔莫瓦河M.; Otten，B. M.; Bhat，S.;阿拉莫湾C.的; Marpu，S. B.;戈尔登，T。D.的;奥马里，M. A.金属配合物是“有机”、“无机”、“有机物”还是“金属-有机”材料？使用三核钴金属络合物作为“金属-有机涂层”抑制铝基材腐蚀的案例研究”，评论Inorg.Chem.2019，39，1-26;和c）Smith，J. B.; Otten，B. M.;德里;布朗宁，C.; Bodenstedt，K. W的; Sandridge，J. H.; Satumtira，N. T.; Zilaie，M.; Payne，J.; Nuti，R.;奥马里，M.一、斯马克，B。W.“Luminescent，Redox-Active（Dithiolato）Bis（Imine）Platinum（II）Divergent Complexes with Exchangeable Imine Ligands：An Experimental/Computational Study versus Their（Diimine）（Dithiolato）Platinum（II）Convergent Congeners”，Comments Inorg.Chem.2019，39，188-215.）本文对双核配合物{Cu[3，5-（CF 3）2 Pz]（µ-dppm）}2和{Cu[3，5-（CF 3）2 Pz]（µ-dppm）}2·3 THF进行了结构、光谱和密度泛函理论研究。它们是通过双（二苯基膦基）甲烷（dppm）与环状三核配合物{μ-[3，5-（CF 3）2 Pz]Cu}3反应还原成核而合成的。采用不同的重结晶条件，得到了两种晶型的固体：{Cu[3，5-（CF 3）2 Pz]（µ-dppm）}2和{Cu[3，5-（CF 3）2 Pz]（µ-dppm）}2·3 THF。通过DFT计算发现{Cu[3，5-（CF 3）2 Pz]（µ-dppm）}2络合物经历了从S 0基态的Y形配位球到T1光激发的最低磷光态的T形配位球的畸变。这种畸变还导致铜-铜键长收缩并形成受激准分子键（dCu-Cu = 2.577 Ω）。实验上，发现晶体中THF的存在引起蓝移，影响发射颜色从蓝绿色到肉眼可见的蓝色的变化，具有接近统一的量子产率（93%），使得后者固体适合于无机LED应用，但不适合OLED，因为薄膜表现出降低的量子产率。晶体学证据表明，THF导致更紧凑的晶格，使复合物更刚性，从而阻碍了激发态扭曲与非溶剂化晶体。更大的失真导致更低的能量辐射发射，从而导致发射颜色的红移。薄膜也进行了研究，并发现进行进一步的红移，作为一个结果，在介质中的刚性较低，更多的表面分子容易变形，从而表现出发光刚性变色光学现象在固态，而不是传统的表现形式在冷冻与流体溶液。在膜和粉末中研究光漂白以评估光稳定性，其在纯固体中上级掺杂固体，这也有利于LED应用。图形摘要
ABSTRACT This paper provides a 4th manifestation of a new tradition by which the editors of Comments on Inorganic Chemistry wish to lead by example, whereby we start publishing original research content that, nonetheless, preserves the Journal’s identity as a niche for critical discussion of contemporary literature in inorganic chemistry. (For the 1st, 2nd and 3rd manifestations, see: a) Otten, B. M.; Melancon, K. M.; Omary, M. A. “All That Glitters is Not Gold: A Computational Study of Covalent vs Metallophilic Bonding in Bimetallic Complexes of d10 Metal Centers – A Tribute to Al Cotton on the 10th Anniversary of His Passing,” Comments Inorg. Chem. 2018, 38, 1–35; b) Yaseen, W. K.; Sanders, S. F.; Almotawa, R. M.; Otten, B. M.; Bhat, S.; Alamo, D. C.; Marpu, S. B.; Golden, T. D.; Omary, M. A. “Are Metal Complexes “Organic”, “Inorganic”, “Organometallic”, or “Metal-Organic” Materials? A Case Study for the Use of Trinuclear Coinage Metal Complexes as “Metal-Organic Coatings” for Corrosion Suppression on Aluminum Substrates”, Comments Inorg. Chem. 2019, 39, 1–26; and c) Smith, J. B.; Otten, B. M.; Derry, P. J.; Browning, C.; Bodenstedt, K. W.; Sandridge, J. H.; Satumtira, N. T.; Zilaie, M.; Payne, J.; Nuti, R.; Omary, M. A.; Smucker, B. W. “Luminescent, Redox-Active (Dithiolato)Bis(Imine)Platinum(II) Divergent Complexes with Exchangeable Imine Ligands: An Experimental/Computational Study versus Their (Diimine)(Dithiolato)Platinum(II) Convergent Congeners”, Comments Inorg. Chem. 2019, 39, 188–215.) Herein, the dinuclear complexes {Cu[3,5-(CF3)2Pz](µ-dppm)}2 and {Cu[3,5-(CF3)2Pz](µ-dppm)}2•3THF were studied structurally, spectroscopically and via density functional theory (DFT). They were synthesized by reacting bis(diphenylphosphino)methane (dppm) with the cyclic trinuclear complex {μ-[3,5-(CF3)2Pz]Cu}3 to effect nuclearity reduction. Two forms of crystalline solids, {Cu[3,5-(CF3)2Pz](µ-dppm)}2 and {Cu[3,5-(CF3)2Pz](µ-dppm)}2•3THF have been obtained using different recrystallization conditions. The {Cu[3,5-(CF3)2Pz](µ-dppm)}2 complex was found through DFT computations to undergo a distortion from a Y-shaped coordination sphere in the S0 ground state toward a T-shape in the T1 photoexcited, lowest-lying, phosphorescent state. The distortion also causes the copper-copper bond length to contract and form an excimer bond (dCu-Cu = 2.577 Å). Experimentally, the presence of THF in the crystal was found to cause a blue shift, effecting a change in emission color from teal to blue to the naked eye, with a near-unity quantum yields (93%), rendering the latter solid suitable for inorganic LED applications but not OLEDs, as thin films exhibit a reduced quantum yield. Crystallographic evidence suggests that THF leads to a more compact lattice that makes the complexes more rigid and thus hinder the excited state distortions vs unsolvated crystals. Greater distortion leads to a lower energy radiative emission and thus a red shift in the emission color. Films were also studied and found to undergo further red shifting as a result of less rigidity in the media and more surface molecules susceptible to distortion, hence manifesting the luminescence rigidochromism optical phenomenon in the solid state as opposed to the traditional manifestation in frozen vs fluid solution. Photobleaching was studied in both the film and powder to assess photostability, which was superior in neat vs doped solids, which is also favorable for LED applications. Graphical Abstract