Beijing National Laboratory for Molecular Sciences
(BNLMS). M.P.A. is the Foreign Young Investigator Awardee
of NSFC (21150110141), China Postdoctoral Science Foundation
(20100480065). The authors thank the Analysis and Test Center
of Huazhong University of Science and Technology for support.
Notes and references
1 (a) Q. T. Meng, X. L. Zhang, C. He, G. J. He, P. Zhou and
C. Y. Duan, Adv. Funct. Mater., 2010, 20, 1903; (b) D. Srikun,
E. W. Miller, D. W. Domaille and C. J. Chang, J. Am. Chem. Soc.,
2008, 130, 4596; (c) K. Hanaoka, Y. Muramatsu, Y. Urano,
T. Terai and T. Nagano, Chem.–Eur. J., 2010, 16, 568; (d) B. Liu
and H. Tian, Chem. Commun., 2005, 3156.
Fig. 2 Emission spectra in THF–water mixtures with different
water fractions at concentration = 10À5 M, excitation wavelength =
367 nm.
2 (a) Z. C. Xu, K.-H. Baek, H. N. Kim, J. N. Cui, X. H. Qian,
D. R. Spring, I. Shin and J. Yoon, J. Am. Chem. Soc., 2010,
132, 601; (b) S. Banthia, M. Sarkar and A. Samanta, Res. Chem.
Intermed., 2005, 31, 25; (c) T. Gunnlaugsson, H. D. P. Ali,
M. Glynn, P. E. Kruger, G. M. Hussey, F. M. Pfeffer, C. M. G.
dos Santos and J. Tierney, J. Fluoresc., 2005, 15, 287;
(d) A. J. Moro, P. J. Cywinski, S. Korsten and G. J. Mohr, Chem.
Commun., 2010, 46, 1085.
3 (a) B. C. Zhu, X. L. Zhang, Y. M. Li, P. F. Wang, H. Y. Zhang and
X. Q. Zhuang, Chem. Commun., 2010, 46, 5710; (b) J. F. Zhang,
C. S. Lim, S. Bhuniya, B. R. Cho and J. S. Kim, Org. Lett., 2011,
13, 1190; (c) R. Umeda, H. Nishida, M. Otono and Y. Nishiyama,
Tetrahedron Lett., 2011, 52, 5494; (d) F. B. Koyuncu, S. Koyuncu
and E. Ozdemir, Synth. Met., 2011, 161, 1005.
4 (a) A. B. Wu, P. Mei, Y. F. Xu and X. H. Qian, Chem. Biol. Drug
Des., 2011, 78, 941; (b) X. Liang, A. B. Wu, Y. F. Xu, K. Xu,
J. W. Liu and X. H. Qian, Invest. New Drugs, 2011, 29, 646.
5 C. Coya, A. L. Alvarez, M. Ramos, R. Gomez, C. Seoane and
J. L. Segura, Synth. Met., 2012, 161, 2580.
6 X. M. Huang, Y. Fang, X. Li, Y. S. Xie and W. H. Zhu, Dyes
Pigm., 2011, 90, 297.
7 (a) M. P. Aldred, C. Li, G. F. Zhang, W. L. Gong, A. D. Q. Li,
Y. Dai, D. Ma and M. Q. Zhu, J. Mater. Chem., 2012, 22, 7515,
and references therein; (b) Y. N. Hong, J. W. Y. Lam and
B. Z. Tang, Chem. Commun., 2009, 4332; (c) Y. N. Hong,
J. W. Y. Lam and B. Z. Tang, Chem. Soc. Rev., 2011, 40, 5361.
8 A. J. Qin, J. W. Y. Lam, F. Mahtab, C. K. W. Jim, L. Tang,
J. Z. Sun, H. H. Y. Sung, I. D. Willams and B. Z. Tang, Appl.
Phys. Lett., 2009, 94, 253308.
9 (a) S. J. Toal, D. Magde and W. J. Trogler, Chem. Commun., 2005,
5465; (b) L. H. Peng, M. Wang, G. X. Zhang, D. Q. Zhang and
D. B. Zhu, Org. Lett., 2009, 11, 1943; (c) Y. Liu, Y. H. Tang,
N. N. Barashkov, I. S. Irgibaeva, J. W. Y. Lam, R. R. Hu,
D. Birimzhanova, Y. Yu and B. Z. Tang, J. Am. Chem. Soc.,
2010, 132, 13951.
10 (a) W. Z. Yuan, P. Lu, S. M. Chen, J. W. Y. Lam, Z. M. Wang,
Y. Liu, H. S. Kwok, Y. G. Ma and B. Z. Tang, Adv. Mater., 2010,
22, 2159; (b) Y. Liu, S. M. Chen, J. W. Y. Lam, F. Mahtab,
H. S. Kwok and B. Z. Tang, J. Mater. Chem., 2012, 22, 5184.
11 B. R. Gao, H. Y. Wang, Y. W. Hao, L. M. Fu, H. H. Fang,
Y. Jiang, L. Wang, Q. D. Chen, H. Xia, L. Y. Pan, Y. G. Ma and
H. B. Sun, J. Phys. Chem. B, 2010, 114, 128.
12 B. Wang, Y. C. Wang, J. L. Hua, Y. H. Jiang, J. H. Huang,
S. X. Qian and H. Tian, Chem.–Eur. J., 2011, 17, 2647.
13 R. R. Hu, E. Lager, A. A. Aguilar, J. Z. Liu, J. W. Y. Lam, H. H. Y.
Sung, I. D. Williams, Y. C. Zhong, K. S. Wong, E. P. Cabrera and
B. Z. Tang, J. Phys. Chem. C, 2009, 113, 15845.
Fig. 3 Changes in PL peak intensities (I/I0) of TPE–NI, in different
THF–water mixtures (I0 = PL intensity in pure THF solution), with
the corresponding photos (below), over a 365 nm illumination source.
influence on the optical properties and the mechanism becomes
dominated by the AIE phenomenon. Of course, the addition of
THF to these nanoparticles reverses the AIE (ESI, Fig. S6w).
The 19 nm blue shift from 80% fw to 90% fw might be due to
changes in morphology. We also observed the same phenomena
in ethanol–water solvent mixtures (ESI, Fig. S7w).
The aggregation size and morphology of TPE–NI in THF–
water (90% fw) was also characterized by scanning electron
microscopy (SEM) and fluorescence microscopy (ESI, Fig. S8w)
and the results indicate that the aggregation mesostructures are
well-defined nanoparticles with strong yellow fluorescence.
In conclusion we have demonstrated a simple design of a
donor–acceptor system utilising TPE as the electron donor and
NI as the electron acceptor. In this system TPE has dual ability to
activate both ICT and AIE phenomena. Strong solvatochromism
is observed with emission covering most part of the visible
spectrum. Also, huge Stokes shifts as large as 12 430 cmÀ1 in
acetonitrile have been observed. This is the first example of a
TPE-based fluorophore to exhibit both AIE and ICT behaviour
without additional electron donating groups in the molecule.
This work was supported by the National Science Foundation
of China (NSFC 20874025, 21174045) and the Open Program for
14 W. Qin, D. Ding, J. Z. Liu, W. Z. Yuan, Y. Hu, B. Liu and
B. Z. Tang, Adv. Funct. Mater., 2012, 22, 771.
15 W. Z. Yuan, Y. Y. Gong, S. M. Chen, X. Y. Shen, J. W. Y. Lam,
P. Lu, Y. W. Lu, Z. M. Wang, R. R. Hu, N. Xie, H. S. Kwok,
Y. M. Zhang, J. Z. Sun and B. Z. Tang, Chem. Mater., 2012,
24, 1518.
c
This journal is The Royal Society of Chemistry 2012
Chem. Commun., 2012, 48, 7711–7713 7713