Chemistry - An Asian Journal
10.1002/asia.201801002
COMMUNICATION
planes are found to be 111.7 and 114.8 (Figure 3a),
respectively, which are rather close to the 109.5 value for a
perfect tetrahedron. Consequently, the molecular stacking
interactions among -conjugated rings are hindered, particularly
for b which has bulky side groups on the phenyl ring. The
packing diagrams (unit cell contents) are presented in Figure 3b,
where triclinic and monoclinic symmetries are found for a (space
group P-1) and b (space group P2 /n), respectively. It is
1
apparent that additional substituents of two methoxy groups can
substantially increase packing complexity for b. Although Figure
improve the RTP performance by rational molecular design is
underway.
Acknowledgements
This work was supported by the National Key R&D Program of
China (2017YFA0303500 to G. Z.), the Fundamental Research
Funds for the Central Universities (WK2340000068 to G. Z.), the
General Financial Grant from China Postdoctoral Science
Foundation (2016M602029 to X.Z.) and the fund from Anhui
Provincial Natural Science Foundation (1708085MB38 to X.Z.).
We are grateful to Mr. Jin Li for drawing the scheme used in the
paper.
3b somewhat suggests -stacking interactions among the
phthalimide rings in both cases, better views may be obtained by
rotating the unit cell to reduce one of the three dimensions,
giving stacked packing diagrams. As can be seen in Figure 3c,
there is only partial stacking interaction for a due to the collision
between the hydrogen atom on the phthalimide and the center
plane of the phenyl ring (marked in red curves). Such clashing
becomes overwhelming for b with the two methoxy groups, so
that an alternative packing (stacked between the phenyl rings) is
adopted with even less stacking interaction among the
phthalimide rings. Since the lowest emissive triplet state resides
in the phthalimide moiety, it is thus not surprising for the
molecule with less interacting phthalimide ring to exhibit stronger
RTP. Consistently, the weaker interaction in b is also reflected
by the blue-shifted RTP maximum (548 nm) compared to a (553
nm). Therefore, we are able to show that the aggregation in the
solid state merely restricts the molecular rotation among the
methylene linker but does not result in significant ground-state
intermolecular interactions, which is essential for AIE (Scheme
Keywords: aggregation-induced emission • donor-acceptor
structure • tetrahedron structure • purely organic • room
temperature phosphorescence
[
[
1]
2]
W. Z. Yuan, P. Lu, S. Chen, J. W. Lam, Z. Wang, Y. Liu, H. S. Kwok, Y.
Ma, B. Z. Tang, Adv. Mater. 2010, 22, 2159-2163.
a) Y. Hong, J. W. Lam, B. Z. Tang, Chem. Soc. Rev. 2011, 40, 5361-
5388; b) J. Mei, N. L. Leung, R. T. Kwok, J. W. Lam, B. Z. Tang, Chem.
Rev. 2015, 115, 11718-11940.
[
3]
a) Y. Gong, L. Zhao, Q. Peng, D. Fan, W. Z. Yuan, Y. Zhang, B. Z.
Tang, Chem. Sci. 2015, 6, 4438-4444; b) J. Li, Y. Jiang, J. Cheng, Y.
Zhang, H. Su, J. W. Lam, H. H. Sung, K. S. Wong, H. S. Kwok, B. Z.
Tang, Phys. Chem. Chem. Phys. 2015, 17, 1134-1141; c) Y. Xiong, Z.
Zhao, W. J. Zhao, H. L. Ma, Q. Peng, Z. K. He, X. P. Zhang, Y. C. Chen,
X. W. He, J. Lam, Angew. Chem. Int. Ed. 2018, 57, 1-6; d) J. Yang, Z.
Ren, B. Chen, M. Fang, Z. Zhao, B. Z. Tang, Q. Peng, Z. Li, J. Mater.
Chem. C 2017, 5, 9242-9246; e) W. Zhao, Z. He, J. W. Lam, Q. Peng,
H. Ma, Z. Shuai, G. Bai, J. Hao, B. Z. Tang, Chem 2016, 1, 592-602.
J. Luo, Z. Xie, J. W. Lam, L. Cheng, H. Chen, C. Qiu, H. S. Kwok, X.
Zhan, Y. Liu, D. Zhu, Chem. Commun. 2001, 1740-1741.
1c).
a)
1
14.8
[4]
[5]
1
11.7
a) X. Chen, C. Xu, T. Wang, C. Zhou, J. Du, Z. Wang, H. Xu, T. Xie, G.
Bi, J. Jiang, Angew. Chem. Int. Ed. 2016, 55, 9872-9876; b) Q. l. M. de
Chermont, C. Chanéac, J. Seguin, F. Pellé, S. Maîtrejean, J. P. Jolivet,
D. Gourier, M. Bessodes, D. Scherman, Proc. Natl. Acad. Sci. 2007,
b)
c)
104, 9266-9271; c) H. F. Wang, Y. He, T. R. Ji, X. P. Yan, Anal. Chem.
2009, 81, 1615-1621; d) G. Zhang, J. Chen, S. J. Payne, S. E. Kooi, J.
Demas, C. L. Fraser, J. Am. Chem. Soc. 2007, 129, 8942-8943; e) G.
Zhang, G. M. Palmer, M. W. Dewhirst, C. L. Fraser, Nat. Mater. 2009, 8,
7
47.
a) R. C. Evans, P. Douglas, C. J. Winscom, Coord. Chem. Rev. 2006,
50, 2093-2126; b) Y. Kawamura, K. Goushi, J. Brooks, J. J. Brown, H.
[
6]
2
Sasabe, C. Adachi, Appl. Phys. Lett. 2005, 86, 071104-071107; c) S. C.
Lo, C. P. Shipley, R. N. Bera, R. E. Harding, A. R. Cowley, P. L. Burn, I.
D. Samuel, Chem. Mater. 2006, 18, 5119-5129; d) Q. Zhang, B. Li, S.
Huang, H. Nomura, H. Tanaka, C. Adachi, Nat. Photonics 2014, 8,
326-332.
Figure 3. a) Stick model showing tetrahedron-like molecular geometries for
both a and b in the solid state (data extracted from single-crystal XRD); b) unit
cells of
complexity; c) bird’s eye view of unit cells down one of the three axes, showing
only partial stacking interactions among the phthalimide rings due to
a and b: additional methoxyl groups on b increases unit cell
[7]
a) Z. An, C. Zheng, Y. Tao, R. Chen, H. Shi, T. Chen, Z. Wang, H. Li, R.
Deng, X. Liu, Nat. Mater. 2015, 14, 685-690; b) S. Cai, H. Shi, J. Li, L.
Gu, Y. Ni, Z. Cheng, S. Wang, W. Xiong, L. Li, Z. An, Adv. Mater. 2017,
29, 1701244-1701249 ; c) S. Cai, H. Shi, D. Tian, H. Ma, Z. Cheng, Q.
Wu, M. Gu, L. Huang, Z. An, Q. Peng, Adv. Funct. Mater. 2018, 28,
hindering effects of the donor moiety.
In conclusion, we present a strategy to construct purely
organic ultralong AIE-RTP by linking an organic donor and
acceptor moiety using a -bonded methylene group. The
1705045-1705051; d) S. Cai, H. Shi, Z. Zhang, X. Wang, H. Ma, N. Gan,
Q. Wu, Z. Cheng, K. Ling, M. Gu, Angew. Chem. Int. Ed. 2018, 57,
“
tetrahedron-like” molecular geometry not only quenches
4005 -4009; e) H. Chen, X. Ma, S. Wu, H. Tian, Angew. Chem. Int. Ed.
luminescence in solution but also minimizes intermolecular
interactions to reduce non-radiative decay pathways in the solid
state. Molecule b exhibits an ultra-long lifetime of 523 ms with a
quantum yield of 3.5% in the air, which is among the longest
purely organic RTP lifetime reported to date. Further study to
2014, 53, 14149-14152; f) Y. Gong, G. Chen, Q. Peng, W. Z. Yuan, Y.
Xie, S. Li, Y. Zhang, B. Z. Tang, Adv. Mater. 2015, 27, 6195-6201; g) S.
Hirata, K. Totani, J. Zhang, T. Yamashita, H. Kaji, S. R. Marder, T.
Watanabe, C. Adachi, Adv. Funct. Mater. 2013, 23, 3386-3397; h) Y.
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