Design and Electroluminescence Properties of Narrow-spectrum Phosphorescent Complexes

doi:10.7503/cjcu20210537

Abstract

Abstract:

Through the design and screening of cyclometalated（C^N） ligands and auxiliary ligands， a new sky blue iridium metal complex （MeFPyPy）₂Ir（dipcMePy）（MFPMP） was constructed， where the optimized proportion of ³LC and ³MLCT/³LLCT transition has been achieved. The MFPMP-based PhOLED realizes narrow spectrum， single peak， high brightness and high efficiency sky blue EL emission with a half peak width of 52 nm and a maximum emission wavelength of 476 nm， achieving an external quantum efficiency（EQE） of more than 25% at a practical luminance of 1000 cd/m²， which can be comparable to that of the highest-level OLEDs reported so far. This work provides a feasible way for further developing the phosphorescent complex materials with higher color purity and more practicability.

Key words: Organic electroluminescence, Iridium metal complex, Guanidine, Narrow spectrum, Color purity

CLC Number:

O614

TrendMD:

ZHANG Huidong, GU Panpan, ZHANG Fang, DU Mingxu, YE Kaiqi, LIU Yu. Design and Electroluminescence Properties of Narrow-spectrum Phosphorescent Complexes[J]. Chem. J. Chinese Universities, 2021, 42(12): 3571.

Figures/Tables 10

Scheme 1 Synthetic procedure of MFPMP

Fig.1 ORTEP plot(A) and packing structures(B, C) of MFPMP by X?ray diffraction

Table 1 Crystal data and structure refinement parameters for MFPMP

Complex	MFPMP	Volume/nm³	3.3517（2）
Formula	C₃₅H₃₆F₄IrN₇	Z	4
Molecular weight	823.3	D_c/（g·cm^-3）	1.631
Crystal system	Monoclinic	Temperature/K	273
Space group	C2/c	μ/mm^-1	4.042
Crystal size/mm	0.38×0.34×0.31	Reflections collected	35977
a/nm	2.10231（7）	Independent reflections	5296（R_int=0.0464， R_sigma=0.0298）
b/nm	1.24947（4）	R_f， R_w（F²）（all data）	R₁=0.0218， wR₂=0.0512
c/nm	1.62509（6）	R_f， R_w（F²）［I>2σ（I）］	R₁=0.0209， wR₂=0.0508
α/（°）	90	GoF	1.064
β/（°）	128.2640（10）	CCDC No.	1860302
γ/（°）	90

Fig.2 UV?Vis absorption(left) and PL(right) spectra of MFPMP in CH2Cl2 at room temperaturePL spectra of PPF films doped with 5% MFPMP. Insets: (A) PL spectrum of MFPMP in THF at low temperature(77 K); (B) transient PL spectra of PPF films doped with 5% MFPMP.

Fig.3 Molecular orbital diagrams with selected isodensity frontier molecular orbitals mainly involved in the electronic transitions of MFPMP

Table 2 Density functional theory results of MFPMP

E_T1^a/eV	E_HOMO/eV	E_LUMO/eV	H?L^b（%）	³MLCT^c（%）	³LLCT^c（%）	³LC^c（%）
2.80	-5.55	-1.57	81	22.64	67.17	6.12

Fig.4 TGA thermogram(A) and DSC thermogram(B) of MFPMP

Fig.5 Cyclic voltammetry curves of MFPMP

Fig.6 Energy level diagram(A) and EL spectra of PhOLED B5(B) and chemical structures for the materials used in PhOLED B5(C)Inset in (B): photographs of PhOLED B5 illuminating at 100 and 1000 nit respectively.

Fig.7 Current density?voltage?luminance(J?V?L) curves(A) and power efficiency(PE)?luminance(L)?external quantum efficiency(EQE) curves(B) of PhOLED B5

References 28

1	Lee J.， Cheng S.， Yoo S.， Shin H.， Chang J.， Wu C.， Wong K.， Kim J.， Adv. Funct. Mater.，2015， 25，361―366
2	Kuo H.， Chen Y.， R. Devereux L.， Wu C.， A. Fox M.， Kuei C.， Chi Y.， Lee G.， Adv. Mater.， 2017， 1702464
3	Li X.， Zhang J.， Zhao Z.， Wang L.， Yang H.， Chang Q.， Jiang N.， Liu Z.， Bian Z.， Liu W.， Lu Z.， Huang C.， Adv. Mater.，2018， 30， 1705005
4	Cho Y. J.， Jeon S. K.， Lee S.， Yu E.， Lee J. Y.， Chem. Mater.， 2016， 28， 5400―5405
5	Im Y.， Kim M.， Cho Y. J.， Seo J.， Yook K. S.， Le J. Y.， Chem. Mater.， 2017， 29， 1946―1963
6	Zeng W.， Zhao Y.， Ning W.， Gong S.， Zhu Z.， Zou Y.， Lu Z.， Yang C.， J. Mater. Chem. C，2018， 6， 4479―4484
7	Park I.， Matsuo K.， Aizawa N.， Yasuda T.， Adv. Funct. Mater.，2018， 28， 1802031
8	Lee C. W.， Lee J. Y.， Chem. Mater.， 2014， 26， 1616―1621
9	Zhao Z.， Yu G.， Chang Q.， Liu X.， Liu Y.， Wang L.， Liu Z.， Bian Z.， Liu W.， Huang C.， J. Mater. Chem. C， 2017， 5， 7344―7351
10	Wang F.， Liu D.， Li J.， Ma M.， Adv. Funct. Mater.，2018， 28， 1803193
11	Cho Y.， Kim S.， Kim J.， Lee J.， Cho D. W.， Yi S.， Son H.， Han W.， Kang S. O.， J. Mater. Chem. C，2017， 5， 1651―1659
12	Chen Z.， Wang L.， Su S.， Zheng X.， Zhu N.， Ho C.， Chen S.， Wong W.， ACS Appl. Mater. Interfaces， 2017， 9， 40497―40502
13	Miao Y.， Tao P.， Gao L.， Li X.， Wei L.， Liu S.， Wang H.， Xue B.， Zhao Q.， J. Mater. Chem. C，2018， 6， 6656―6665
14	Xia J.， Liang X.， Yan Z.，Wu Z.， Zhao Y.， Zheng Y.， Zhang W.， J. Mater. Chem. C. 2018， 6， 9010―9016
15	Spellane P.， Watts R. J.， Inorg. Chem.， 1993， 32， 5633―5636
16	Tsuboyama A.， Iwawaki H.， Furugori M.， Mukaide T.， Kamatani J.， Igawa S.， Moriyama T.， Miura S.， Takiguchi T.， Okada S.， Hoshino M.， Ueno K.， J. Am. Chem. Soc.， 2003， 125， 12971―12979
17	Chou P.， Chi Y.， Chem. Eur. J.， 2007， 13， 380―395
18	Li G.， Zhu D.， Peng T.， Liu Y.， Wang Y.， Bryce M. R.， Adv. Funct. Mater.，2014， 24， 7420―7426
19	Feng Y.， Li P.， Zhuang X.， Ye K.， Peng T.， Liu Y.， Wang Y.， Chem. Commun.，2015， 51， 12544―12547
20	Du M.， Wang Y.， Wang J.， Chen S.， Wang Z.， Wang S.， Bai F.， Liu Y.， Wang Y.， J. Mater. Chem. C，2019， 7， 5579―5583
21	Jiao Y.， Li M.， Wang N.， Lu T.， Zhou L.， Huang Y.， Lu Z.， Luo D.， Pu X.， J. Mater. Chem. C，2016， 4， 4269―4277
22	Wu Z.， Jing Y.， Lu G.， Zhou J.， Zheng Y.， Zhou L.， Wang Y.， Pan Y.， Sci. Rep.， 2016， 6， 38478
23	Hay P. J.， J. Phys. Chem. A， 2002， 106， 1634―1641
24	Yan Z.， Wang Y.， Ding J.， Wang Y.， Wang L.， ACS Appl. Mater. Interfaces， 2018， 10， 1888―1896
25	Lai P.， Brysacz C. H.， Alam M. K.， Ayoub N. A.， Gray T. G.， Bao J.， Teets T. S.， J. Am. Chem. Soc.， 2018， 140， 10198―10207
26	Feng Z.， Wang D.， Yang X.， Jin D.， Zhong D.， Liu B.， Zhou G.， Ma M.， Wu Z.， Inorg. Chem.， 2018， 57， 11027―11043
27	Feng Y.， Zhuang X.， Zhu D.， Liu Y.， Wang Y.， Bryce M. R.， J. Mater. Chem. C，2016， 4， 10246―10252
28	Li G.， Li P.， Zhuang X.， Ye K.， Liu Y.， Wang Y.， ACS Appl. Mater. Interfaces， 2017， 9， 11749―11758

[1]	WEI Liangchen, HU Weikang, ZHOU Shixiong, SHU Jun, ZHOU Huidong, HU Xucheng, JIANG Yi, TONG Bihai, ZHANG Qianfeng. Iridium Complex Containing Phosphite and Bipyridine Carboxylate Ligands and Their Aggregation Induced Enhanced Emission and Electroluminescent Properties^† [J]. Chem. J. Chinese Universities, 2018, 39(7): 1371.
[2]	LI Weijun, GAO Zhao, WANG Zhiming, YANG Bing, LU Ping, MA Yuguang. Highly Efficient Blue Electroluminescent Materials Based on Phenanthro[9,10-d]imidazole^† [J]. Chem. J. Chinese Universities, 2014, 35(9): 1849.
[3]	LI Xia, CAO Yiming, KANG Guodong, YU Haijun, LIU Zhongnan. Preparation of Antimicrobial Nanofiltration Membrane via Self-polymerization of Dopamine and Surface Grafting of PHGH^† [J]. Chem. J. Chinese Universities, 2014, 35(9): 2026.
[4]	WANG Zhiming, FENG Ying, LI Hui, SONG Xiaohui, LU Ping. Preparation and Characterization of Phenanthroimidazole-based Derivatives with Ether Linkage at N1-Phenyl^† [J]. Chem. J. Chinese Universities, 2014, 35(8): 1691.
[5]	YANG Dongyan, WANG Lei, JIA Changqing, LI Changsheng, MA Yongqiang, RUI Changhui, XU Yanjun, QIN Zhaohai. Syntheses and Insecticidal Activities of Nitro Arylideneamino Guanidine Derivatives^† [J]. Chem. J. Chinese Universities, 2014, 35(8): 1703.
[6]	ZHANG Qi, LU Suhui, ZHENG Anna, GUAN Yong, WEI Dafu, HUANG Tianhua, LI Shuzhao. Preparation and Characterization of Long-acting Antimicrobial Polyethylene Terephthalate via Covalent Bonding Method^† [J]. Chem. J. Chinese Universities, 2014, 35(4): 873.
[7]	WANG Zhiming, SONG Xiaohui, LI Hui, FENG Ying, LU Ping. Effects on Fluorescence Color Purity of Phenanthroimidazole Derivatives from N1 Substituted Group^† [J]. Chem. J. Chinese Universities, 2014, 35(3): 505.
[8]	FENG Xuan, ZHANG Tan, BIAN Liu-Jiao. Distribution and Transition of Stable Conformations of Denatured Hen Egg White Lysozymes During Their Refolding in Guanidine Hydrochloride Solutions [J]. Chem. J. Chinese Universities, 2013, 34(2): 336.
[9]	ZHANG Tan, BIAN Liu-Jiao*. Distribution and Transition of Stable Conformations of Hen Egg White Lysozymes in Their Unfolding Induced by Urea and Guanidine Hydrochloride Solutions [J]. Chem. J. Chinese Universities, 2011, 32(7): 1497.
[10]	LU Qing-Xia, TAN Hong-Wei, CHEN Guang-Ju, WANG Yan. Theoretical Studies on Electronic Structures and Catalytic Activities of Superoxide Dismutase Mimetics of Imidazolate-bridged Dinuclear Cu(Ⅱ) Complexes [J]. Chem. J. Chinese Universities, 2008, 29(8): 1635.
[11]	XIE Wei-Jie^1,2, LI Yu-Peng^1,2, SUN Cheng-Lin³, LI Feng¹, FEI Teng¹, MA Yu-Guang¹. Preparation of Organic White Light-emitting Devices via Exciplex Emission [J]. Chem. J. Chinese Universities, 2007, 28(7): 1342.
[12]	SONG Wei, LU Xiao-Feng, LU Guo-Yuan. Synthesis of Phenylenedimethylene Bis(guanidiniums) Derivatives [J]. Chem. J. Chinese Universities, 2006, 27(3): 460.
[13]	WANG Guang, WANG Li-Xiang, JING Xia-Bin, WANG Fo-Song . Synthesis, Photoluminescence and Electroluminescence of Beryllium(Ⅱ) Complex with 2-Naphthalene-substituted Oxadiazole [J]. Chem. J. Chinese Universities, 2003, 24(7): 1158.
[14]	HE Yi, WANG Guang, CHEN Jie-Sheng. Synthesis, Photoluminescence and Electroluminescence of₈-Hydroxyquinolato-p-methylphenolato-zinc [J]. Chem. J. Chinese Universities, 2002, 23(9): 1667.
[15]	ZHANG Ke-Sheng, SUN Jun-Tan, HE Bing-Lin . Preparation of New Adsorbent for Bilirubin by Immobilizing Guanidine on Cross-linked Polyvinyl Alcohol Gel [J]. Chem. J. Chinese Universities, 1999, 20(6): 965.