Blue fluorophores comprised of tetraphenylethene and imidazole: aggregation-induced emission and electroluminescence

doi:10.1007/s12200-015-0522-y

Front. Optoelectron.

2015, Vol. 8

Issue (3) : 274-281 https://doi.org/10.1007/s12200-015-0522-y

RESEARCH ARTICLE

Blue fluorophores comprised of tetraphenylethene and imidazole: aggregation-induced emission and electroluminescence

Jiayun XIANG¹,Han NIE²,Yibin JIANG³,Jian ZHOU¹,Hoi Sing KWOK³,Zujin ZHAO^1,^2,^*(

),Ben Zhong TANG^2,^4,^*(

)

1. College of Material, Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 310036, China
2. Guangdong Innovative Research Team, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
3. Center for Display Research, The Hong Kong University of Science & Technology, Kowloon, Hong Kong, China
4. Department of Chemistry, Division of Biomedical Engineering, Division of Life Science, The Hong Kong University of Science & Technology, Kowloon, Hong Kong, China

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Abstract

By melting tetraphenylethene (TPE) and 1,2,4,5-tetraphenyl-1H-imidazole (TPI) units together through different linking positions, three new fluorophores are synthesized, and their optical, electronic and electroluminescence (EL) properties are fully studied. Owing to the presence of TPE unit(s), these fluorophores are weak emitters in solutions, but are induced to emit strongly in the aggregated state, presenting typical aggregation-induced emission characteristics. The experimental and computational results reveal that different connection patterns between TPE and TPI could impact the molecular conjugation greatly, leading to varied emission wavelength, fluorescence quantum yield and EL performance in organic light emitting diodes (OLEDs). The fluorophore built by attaching TPE unit to the 1-position of imidazole ring shows bluest fluorescence, and its EL device emits at deep blue region (445 nm; CIE= (0.16, 0.15)). And the device based on the fluorophore by linking TPE to the 2-position of imidazole ring shows EL at 467 nm (CIE= (0.17, 0.22)) with good efficiencies of 3.17 cd·A^-1, and 1.77%.

Keywords aggregation-induced emission (AIE) tetraphenylethene (TPE) imidazole blue fluorescence organic light emitting diode (OLED)

Corresponding Author(s): Zujin ZHAO,Ben Zhong TANG

Just Accepted Date: 12 June 2015 Online First Date: 17 August 2015 Issue Date: 18 September 2015

Cite this article:

Jiayun XIANG,Han NIE,Yibin JIANG, et al. Blue fluorophores comprised of tetraphenylethene and imidazole: aggregation-induced emission and electroluminescence[J]. Front. Optoelectron., 2015, 8(3): 274-281.

URL:

https://academic.hep.com.cn/foe/EN/10.1007/s12200-015-0522-y
https://academic.hep.com.cn/foe/EN/Y2015/V8/I3/274

Fig.1 Scheme 1 Molecular structures and synthesis of the new fluorophores

Fig.2 (a) Absorption spectra in THF solutions (10^-5 M) and (b) PL spectra in solid films of the new fluorophores

Tab.1 Optical properties and energy levels of the new fluorophores

Fig.3 CV curves of the new fluorophores in acetonitrile solution with 0.1 M tetrabutylammonium hexafluorophosphate as the supporting electrolyte at a scan rate of 50 mV·s^-1

Fig.4 Calculated molecular orbital amplitude plots of HOMOs and LUMOs for the new fluorphores

Fig.5 (a) EL spectra; (b) current density-voltage-luminance characteristics; and (c) changes in current efficiency with the current density in multilayer EL devices of these new fluorophores [ITO/NPB (60 nm)/EML (20 nm)/TPBi (40 nm)/LiF (1 nm)/Al (100 nm)]

Tab.2 EL performance of the new fluorophores^a)

1	Farinola G M, Ragni R. Electroluminescent materials for white organic light emitting diodes. Chemical Society Reviews, 2011, 40(7): 3467&horbar;3482 https://doi.org/10.1039/c0cs00204f pmid: 21437308
2	Samuel I D W, Turnbull G A. Organic semiconductor lasers. Chemical Reviews, 2007, 107(4): 1272&horbar;1295 https://doi.org/10.1021/cr050152i pmid: 17385928
3	Basabe-Desmonts L, Reinhoudt D N, Crego-Calama M. Design of fluorescent materials for chemical sensing. Chemical Society Reviews, 2007, 36(6): 993&horbar;1017 https://doi.org/10.1039/b609548h pmid: 17534482
4	Valeur B. Molecular Fluorescence: Principles and Applications. London: Wiley, 2001, 74&horbar;84
5	Grimsdale A C, Chan K L, Martin R E, Jokisz P G, Holmes A B. Synthesis of light-emitting conjugated polymers for applications in electroluminescent devices. Chemical Reviews, 2009, 109(3): 897&horbar;1091 https://doi.org/10.1021/cr000013v pmid: 19228015
6	Gaylord B S, Wang S, Heeger A J, Bazan G C. Water-soluble conjugated oligomers: effect of chain length and aggregation on photoluminescence-quenching efficiencies. Journal of the American Chemistry Society, 2001, 123(26): 6417&horbar;6418 https://doi.org/10.1021/ja010373f pmid: 11427069
7	Luo J, Xie Z, Lam J W Y, Cheng L, Chen H, Qiu C, Kwok H S, Zhan X, Liu Y, Zhu D, Tang B Z. Aggregation-induced emission of 1-methyl-1,2,3,4,5-pentaphenylsilole. Chemical Communications, 2001, 18(18): 1740&horbar;1741 https://doi.org/10.1039/b105159h pmid: 12240292
8	Mei J, Hong Y, Lam J W Y, Qin A, Tang Y, Tang B Z. Aggregation-induced emission: the whole is more brilliant than the parts. Advanced Materials, 2014, 26(31): 5429&horbar;5479 https://doi.org/10.1002/adma.201401356 pmid: 24975272
9	Zhao Z, Lu P, Lam J W Y, Wang Z, Chan C Y K, Sung H H Y, Williams I D, Ma Y, Tang B Z. Molecular anchors in the solid state: restriction of intramolecular rotation boosts emission efficiency of fluorophore aggregates to unity. Chemical Science (Cambridge), 2011, 2(4): 672&horbar;675 https://doi.org/10.1039/C0SC00521E
10	Chen L, Jiang Y, Nie H, Hu R, Kwok H S, Huang F, Qin A, Zhao Z, Tang B Z. Rational design of aggregation-induced emission luminogen with weak electron donor-acceptor interaction to achieve highly efficient undoped bilayer OLEDs. ACS Applied Materials & Interfaces, 2014, 6(19): 17215&horbar;17225 https://doi.org/10.1021/am505036a pmid: 25254940
11	Liu Y, Chen S, Lam J W Y, Lu P, Kwok R T K, Mahtab F, Kwok H S, Tang B Z.Tuning the electronic nature of aggregation-induced emission fluorophores with enhanced hole-transporting property. Chemistry of Materials, 2011, 23(10): 2536&horbar;2544 https://doi.org/10.1021/cm2003269
12	Chou H H, Chen Y H, Hsu H P, Chang W H, Chen Y H, Cheng C H. Synthesis of diimidazolylstilbenes as n-type blue fluorophores: alternative dopant materials for highly efficient electroluminescent devices. Advanced Materials, 2012, 24(43): 5867&horbar;5871 https://doi.org/10.1002/adma.201202222 pmid: 22915130
13	Nagarajan N, Prakash A, Velmurugan G, Shakti N, Katiyar M, Venuvanalingam P, Renganathan R. Synthesis, characterisation and electroluminescence behaviourof π-conjugated imidazole-isoquinoline derivatives. Dyes and Pigments, 2014, 102: 180&horbar;188 https://doi.org/10.1016/j.dyepig.2013.11.002
14	Li W, Yao L, Liu H, Wang Z, Zhang S, Xiao R, Zhang H, Lu P, Yang B, Ma Y. Highly efficient deep-blue OLED with anextraordinarily narrow FHWM of 35 nm and a γ coordinate<0.05 based on a fully twisting donor-acceptor molecule. Journal of Materials Chemistry C, 2014, 2(24): 4733&horbar;4736 https://doi.org/10.1039/C4TC00487F
15	Ma C, Xu B, Xie G, He J, Zhou X, Peng B, Jiang L, Xu B, Tian W, Chi Z, Liu S, Zhang Y, Xu J. An AIE-active luminophore with tunable and remarkable fluorescence switching based on the piezo and protonation-deprotonation control. Chemical Communications, 2014, 50(55): 7374&horbar;7377 https://doi.org/10.1039/c4cc01012d pmid: 24872230
16	Luo M, Zhou X, Chi Z, Liu S, Zhang Y, Xu J. Fluorescence-enhanced organogelators with mesomorphic and piezofluorochromic properties based on tetraphenylethylene and gallic acid derivatives. Dyes and Pigments, 2014, 101: 74&horbar;84 https://doi.org/10.1016/j.dyepig.2013.08.026
17	Frisch M J, Trucks G W, Schlegel H B, Scuseria G E, Robb M A, Cheeseman J R, Scalmani G, Barone V, Mennucci B, Petersson G A, Nakatsuji H, Caricato M, Li X, Hratchian H P, Izmaylov A F, Bloino J, Zheng G, Sonnenberg J L, Hada M, Ehara M, Toyota K, Fukuda R, Hasegawa J, Ishida M, Nakajima T, Honda Y, Kitao O, Nakai H, Vreven T, Montgomery J A Jr, Peralta J E, Ogliaro F, Bearpark M, Heyd J J, Brothers E, Kudin K N, Staroverov V N, Kobayashi R, Normand J, Raghavachari K, Rendell A, Burant J C, Iyengar S S, Tomasi J, Cossi M, Rega N, Millam N J, Klene M, Knox J E, Cross J B, Bakken V, Adamo C, Jaramillo J, Gomperts R, Stratmann R E, Yazyev O, Austin A J, Cammi R, Pomelli C, Ochterski J W, Martin R L, Morokuma K, Zakrzewski V G, Voth G A, Salvador P, Dannenberg J J, Dapprich S, Daniels A D, Farkas ?, Foresman J B, Ortiz J V, Cioslowski J, Fox D J. Gaussian 09, Revision D.01. Gaussian Inc. Wallingford CT, 2009
18	Huang J, Sun N, Dong Y, Tang R, Lu P, Cai P, Li Q, Ma D, Qin J, Li Z. Similar or totally different: the control of conjugation degree through minor structural modifications, and deep-blue aggregation-induced emissionluminogens for non-doped OLEDs. Advanced Functional Materials, 2013, 23(18): 2329&horbar;2337 https://doi.org/10.1002/adfm.201202639
19	Zhao Z, Chen S, Shen X, Mahtab F, Yu Y, Lu P, Lam J W Y, Kwok H S, Tang B Z. Aggregation-induced emission, self-assembly, and electroluminescence of 4,4′-bis(1,2,2-triphenylvinyl)biphenyl. Chemical Communications, 2010, 46(5): 686&horbar;688 https://doi.org/10.1039/B915271G pmid: 20087487
20	Zhao Z, Chen S, Lam J W Y, Lu P, Zhong Y, Wong K S, Kwok H S, Tang B Z. Creation of highly efficient solid emitter by decorating pyrene core with AIE-active tetraphenylethene peripheries. Chemical Communications, 2010, 46(13): 2221&horbar;2223 https://doi.org/10.1039/b921451h pmid: 20234912

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