

FOLLOWUS
a.Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Engineering Research Center for Biomaterials and Medical Protective Materials, Hubei Key Laboratory of Materials Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
b.State Key Laboratory of Material Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430074, China
wukong.s@163.com (Y.Q.)
ygliao@mail.hust.edu.cn (Y.G.L.)
Received:10 May 2021,
Revised:2021-6-5,
Accepted:09 June 2021,
Online First:30 July 2021,
Published:18 October 2021
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Zhao, D. X.; Jiang, Q.; Wang, J.; Qiu, Y.; Liao, Y. G.; Xie, X. L. Visible light and temperature regulated reflection colors in self-supporting cholesteric liquid crystal physical gels. Chinese J. Polym. Sci. 2021, 39, 1617–1625
Dong-Xu Zhao, Qian Jiang, Jing Wang, et al. Visible Light and Temperature Regulated Reflection Colors in Self-supporting Cholesteric Liquid Crystal Physical Gels[J]. Chinese Journal of Polymer Science, 2021, 39(12): 1617-1625.
Zhao, D. X.; Jiang, Q.; Wang, J.; Qiu, Y.; Liao, Y. G.; Xie, X. L. Visible light and temperature regulated reflection colors in self-supporting cholesteric liquid crystal physical gels. Chinese J. Polym. Sci. 2021, 39, 1617–1625 DOI: 10.1007/s10118-021-2618-8.
Dong-Xu Zhao, Qian Jiang, Jing Wang, et al. Visible Light and Temperature Regulated Reflection Colors in Self-supporting Cholesteric Liquid Crystal Physical Gels[J]. Chinese Journal of Polymer Science, 2021, 39(12): 1617-1625. DOI: 10.1007/s10118-021-2618-8.
Photo-responsive cholesteric liquid crystals (CLCs) have attracted much attention in recent years due to their wide applications in filters
tunable optical lasers
dynamic display devices
etc
. However
UV light is usually used as the external stimulus source
which is not environment-friendly enough. On the other hand
the mechanical properties of CLCs are not strong enough for these practical applications. Therefore
it still remains a challenge to endow the CLCs with visible light response and high mechanical properties at the same time. Herein
an axially chiral tetra-fluorinated binaphthyl azobenzene gelator (
S-4F-AG
) is synthesized. Upon 550 and 450 nm light irradiations
S-4F-AG
exhibits excellent photo-switchable behaviors. Notably
the maximum content of
cis
-isomer and its half-life are as high as 35% and 89 h in acetonitrile
respectively. A self-supporting CLC physical gel with a storage modulus around 10
4
Pa can be obtained when 3wt%
S-4F-AG
and 12wt% binaphthyl azobenzene derivative (dopant
2
) are co-doped into a nematic LC host P0616A. This CLC physical gel exhibits a temperature-driven blue
green
and red reflection colors reversibly. Importantly
such three primary RGB colors can also be realized by adjusting the exposure time of 550 nm green light. This work lays a solid foundation for the applications ranging from information storage to high-tech anticounterfeit.
Xiang, J.; Li, Y.; Li, Q.; Paterson, D. A.; Storey, J. M. D.; Imrie, C. T.; Lavrentovich, O. D. . Electrically tunable selective reflection of light from ultraviolet to visible and infrared by heliconical cholesterics . Adv. Mater. , 2015 . 27 3014 - 3018 . DOI: 10.1002/adma.201500340 http://doi.org/10.1002/adma.201500340 .
Furumi, S.; Tamaoki, N. . Glass-forming cholesteric liquid crystal oligomers for new tunable solid-state laser . Adv. Mater. , 2010 . 22 886 - 891 . DOI: 10.1002/adma.200902552 http://doi.org/10.1002/adma.200902552 .
Chen, F. J.; Guo, J. B.; Jin, O. Y.; Wei, J. . A temperature and pH double sensitive cholesteric polymer film from a photopolymerizable chiral hydrogen-bonded assembly . Chinese J. Polym. Sci. , 2013 . 31 630 - 640 . DOI: 10.1007/s10118-013-1244-5 http://doi.org/10.1007/s10118-013-1244-5 .
Chen, P.; Ma, L. L.; Hu, W.; Shen, Z. X.; Bisoyi, H. K.; Wu, S. B.; Ge, S. J.; Li, Q.; Lu, Y. Q. . Chirality invertible superstructure mediated active planar optics . Nat. Commun. , 2019 . 10 2518 DOI: 10.1038/s41467-019-10538-w http://doi.org/10.1038/s41467-019-10538-w .
Wang, Y.; Li, Q. . Light-driven chiral molecular switches or motors in liquid crystals . Adv. Mater. , 2012 . 24 1926 - 1945 . DOI: 10.1002/adma.201200241 http://doi.org/10.1002/adma.201200241 .
Wang, L.; Dong, H.; Li, Y.; Liu, R.; Wang, Y. F.; Bisoyi, H. K.; Sun, L. D.; Yan, C. H.; Li, Q. . Luminescence-driven reversible handedness inversion of self-organized helical superstructures enabled by a novel near-infrared light nanotransducer . Adv. Mater. , 2015 . 27 2065 - 2069 . DOI: 10.1002/adma.201405690 http://doi.org/10.1002/adma.201405690 .
Jiao, T.; Wang, Y.; Gao, F.; Zhou, J.; Gao, F. . Photoresponsive organogel and organized nanostructures of cholesterol imide derivatives with azobenzene substituent groups . Prog. Nat. Sci. Mater. Int. , 2012 . 22 64 - 70 . DOI: 10.1016/j.pnsc.2011.12.011 http://doi.org/10.1016/j.pnsc.2011.12.011 .
Li, Q.; Li, Y.; Ma, J.; Yang, D. K.; White, T. J.; Bunning, T. J. . Directing dynamic control of red, green, and blue reflection enabled by a light-driven self-organized helical superstructure . Adv. Mater. , 2011 . 23 5069 - 5073 . DOI: 10.1002/adma.201103362 http://doi.org/10.1002/adma.201103362 .
Han, S. Q.; Chen, Y. Y.; Xu, B.; Wei, J.; Yu, Y. L. . An azoester-containing photoresponsive linear liquid crystal polymer with good mesophase stability . Chinese J. Polym. Sci. , 2020 . 38 806 - 813 . DOI: 10.1007/s10118-020-2383-0 http://doi.org/10.1007/s10118-020-2383-0 .
Li, Q.; Green, L.; Venkataraman, N.; Shiyanovskaya, I.; Khan, A.; Urbas, A.; Doane, J. W. . Reversible photoswitchable axially chiral dopants with high helical twisting power . J. Am. Chem. Soc. , 2007 . 129 12908 - 12909 . DOI: 10.1021/ja0747573 http://doi.org/10.1021/ja0747573 .
White, T. J.; Bricker, R. L.; Natarajan, L. V.; Tabiryan, N. V.; Green, L.; Li, Q.; Bunning, T. J. . Phototunable azobenzene cholesteric liquid crystals with 2000 nm range . Adv. Funct. Mater. , 2009 . 19 3484 - 3488 . DOI: 10.1002/adfm.200900396 http://doi.org/10.1002/adfm.200900396 .
Wang, H.; Bisoyi, H. K.; Wang, L.; Urbas, A. M.; Bunning, T. J.; Li, Q. . Photochemically and thermally driven full-color reflection in a self-organized helical superstructure enabled by a halogen-bonded chiral molecular switch . Angew. Chem. Int. Ed. , 2018 . 57 1627 - 1631 . DOI: 10.1002/anie.201712781 http://doi.org/10.1002/anie.201712781 .
Guan, S.; Deng, Z.; Huang, T.; Wen, W.; Zhao, Y.; Chen, A. . Light-triggered reversible slimming of azobenzene-containing wormlike nanoparticles synthesized by polymerization-induced self-assembly for nanofiltration switches . ACS Macro Lett. , 2019 . 8 460 - 465 . DOI: 10.1021/acsmacrolett.9b00146 http://doi.org/10.1021/acsmacrolett.9b00146 .
Liu, X.; Qin, L.; Zhan, Y.; Chen, M.; Yu, Y. . Phototuning of structural colors in cholesteric liquid crystals . Acta Chim. Sinica , 2020 . 78 478 - 489 . DOI: 10.6023/A20040103 http://doi.org/10.6023/A20040103 .
Lin, S.; Gutierrez-Cuevas, K. G.; Zhang, X.; Guo, J.; Li, Q. . Fluorescent photochromic α -cyanodiarylethene molecular switches: an emerging and promising class of functional diarylethene . Adv. Funct. Mater. , 2021 . 31 2007957 DOI: 10.1002/adfm.202007957 http://doi.org/10.1002/adfm.202007957 .
Wen, W.; Ouyang, W.; Guan, S.; Chen, A. . Synthesis of azobenzene-containing liquid crystalline block copolymer nanoparticles via polymerization induced hierarchical self-assembly . Polym. Chem. , 2021 . 12 458 - 465 . DOI: 10.1039/D0PY01442G http://doi.org/10.1039/D0PY01442G .
Fan, J.; Li, Y.; Bisoyi, H. K.; Zola, R. S.; Yang, D. K.; Bunning, T. J.; Weitz, D. A.; Li, Q. . Light-directing omnidirectional circularly polarized reflection from liquid-crystal droplets . Angew. Chem. Int. Ed. , 2015 . 54 2160 - 2164 . DOI: 10.1002/anie.201410788 http://doi.org/10.1002/anie.201410788 .
Li, Y.; Urbas, A.; Li, Q. . Reversible light-directed red, green, and blue reflection with thermal stability enabled by a self-organized helical superstructure . J. Am. Chem. Soc. , 2012 . 134 9573 - 9576 . DOI: 10.1021/ja302772z http://doi.org/10.1021/ja302772z .
Delden, R. A. v.; Koumura, N.; Haradat, N.; Feringa, B. L. . Unidirectional rotary motion in a liquid crystalline environment: color tuning by a molecular motor . Proc. Natl. Acad. Sci. U. S. A. , 2002 . 99 4945 - 4949 . DOI: 10.1073/pnas.062660699 http://doi.org/10.1073/pnas.062660699 .
Li, J.; Bisoyi, H. K.; Tian, J.; Guo, J.; Li, Q. . Optically rewritable transparent liquid crystal displays enabled by light-driven chiral fluorescent molecular switches . Adv. Mater. , 2019 . 31 1807751 DOI: 10.1002/adma.201807751 http://doi.org/10.1002/adma.201807751 .
Li, J.; Zhang, Z.; Tian, J.; Li, G.; Wei, J.; Guo, J. . Dicyanodistyrylbenzene-based chiral fluorescence photoswitches: an emerging class of multifunctional switches for dual-mode phototunable liquid crystals . Adv. Opt. Mater. , 2017 . 5 1700014 DOI: 10.1002/adom.201700014 http://doi.org/10.1002/adom.201700014 .
Zhang, Z. W.; Li, J. T.; Wei, W. Y.; Wei, J.; Guo, J. B. . A luminescent dicyanodistyrylbenzene-based liquid crystal polymer network for photochemically patterned photonic composite film . Chinese J. Polym. Sci. , 2018 . 36 776 - 782 . DOI: 10.1007/s10118-018-2072-4 http://doi.org/10.1007/s10118-018-2072-4 .
White, T. J.; McConney, M. E.; Bunning, T. J. . Dynamic color in stimuli-responsive cholesteric liquid crystals . J. Mater. Chem. , 2010 . 20 9832 - 9847 . DOI: 10.1039/c0jm00843e http://doi.org/10.1039/c0jm00843e .
Ma, J.; Li, Y.; White, T.; Urbas, A.; Li, Q. . Light-driven nanoscale chiral molecular switch: reversible dynamic full range color phototuning . Chem. Commun. , 2010 . 46 3463 - 3465 . DOI: 10.1039/c002436h http://doi.org/10.1039/c002436h .
Tong, X.; Qiu, Y.; Zhao, X.; Xiong, B.; Liao, R.; Peng, H.; Liao, Y.; Xie, X. . Visible light-triggered gel-to-sol transition in halogen-bond-based supramolecules . Soft Matter , 2019 . 15 6411 - 6417 . DOI: 10.1039/C9SM01310E http://doi.org/10.1039/C9SM01310E .
Tong, X.; Zhao, X.; Qiu, Y.; Wang, H.; Liao, Y.; Xie, X. . Intrinsically visible light-responsive liquid crystalline physical gels driven by a halogen bond . Langmuir , 2020 . 36 11873 - 11879 . DOI: 10.1021/acs.langmuir.0c01901 http://doi.org/10.1021/acs.langmuir.0c01901 .
Yin, R.; Xu, W.; Kondo, M.; Yen, C. C.; Mamiya, J.; Ikeda, T.; Yu, Y. . Can sunlight drive the photoinduced bending of polymer films? . J. Mater. Chem. , 2009 . 19 3141 - 3143 . DOI: 10.1039/b904973h http://doi.org/10.1039/b904973h .
Knie, C.; Utecht, M.; Zhao, F.; Kulla, H.; Kovalenko, S.; Brouwer, A. M.; Saalfrank, P.; Hecht, S.; Bléger, D. . Ortho -fluoroazobenzenes: Visible light switches with very long-lived Z isomers . Chem. Eur. J. , 2014 . 20 16492 - 16501 . DOI: 10.1002/chem.201404649 http://doi.org/10.1002/chem.201404649 .
Bléger, D.; Schwarz, J.; Brouwer, A. M.; Hecht, S. . Ortho -fluoroazobenzenes as readily synthesized photoswitches offering nearly quantitative two-way isomerization with visible light . J. Am. Chem. Soc. , 2012 . 134 20597 - 20600 . DOI: 10.1021/ja310323y http://doi.org/10.1021/ja310323y .
Qin, L.; Gu, W.; Wei, J.; Yu, Y. . Piecewise phototuning of self-organized helical superstructures . Adv. Mater. , 2018 . 30 1704941 DOI: 10.1002/adma.201704941 http://doi.org/10.1002/adma.201704941 .
Qin, L.; Wei, J.; Yu, Y. . Photostationary RGB selective reflection from self-organized helical superstructures for continuous photopatterning . Adv. Opt. Mater. , 2019 . 7 1900430 DOI: 10.1002/adom.201900430 http://doi.org/10.1002/adom.201900430 .
Wang, H.; Bisoyi, H. K.; Urbas, A. M.; Bunning, T. J.; Li, Q. . Reversible circularly polarized reflection in a self-organized helical superstructure enabled by a visible-light-driven axially chiral molecular switch . J. Am. Chem. Soc. , 2019 . 141 8078 - 8082 . .
Kato, T.; Hirai, Y.; Nakaso, S.; Moriyama, M. . Liquid-crystalline physical gels . Chem. Soc. Rev. , 2007 . 36 1857 - 1867 . DOI: 10.1039/b612546h http://doi.org/10.1039/b612546h .
Chen, J. W.; Kuo, Y. Y.; Wang, C. R.; Chao, C. Y. . The formation of supramolecular liquid-crystal gels for enhancing the electro-optical properties of twisted nematic liquid crystals . Org. Electron. , 2015 . 27 24 - 28 . DOI: 10.1016/j.orgel.2015.08.027 http://doi.org/10.1016/j.orgel.2015.08.027 .
Chen, S.; Luo, X.; He, H.; Tong, X.; Wu, B.; Ma, M.; Wang, X. . Stretchable light scattering display based on super strong liquid crystalline physical gels with special loofah-like 3D gel networks . J. Mater. Chem. C , 2015 . 3 12026 - 12031 . DOI: 10.1039/C5TC02196K http://doi.org/10.1039/C5TC02196K .
Zhao, D.; Ouyang, D.; Jiang, M.; Liao, Y.; Peng, H.; Xie, X. . Photomodulated electro-optical response in self-supporting liquid crystalline physical gels . Langmuir , 2018 . 34 7519 - 7526 . DOI: 10.1021/acs.langmuir.8b01031 http://doi.org/10.1021/acs.langmuir.8b01031 .
Zhao, D.; Qiu, Y.; Cheng, W.; Bi, S.; Wang, H.; Wang, Q.; Liao, Y.; Peng, H.; Xie, X. . Precisely tuning helical twisting power via photoisomerization kinetics of dopants in chiral nematic liquid crystals . Langmuir , 2018 . 34 700 - 708 . DOI: 10.1021/acs.langmuir.7b03786 http://doi.org/10.1021/acs.langmuir.7b03786 .
Zhao, D.; Zhao, X.; Wang, J.; Peng, H.; Liao, Y.; Xie, X.; Smalyukh, I. I.; Yu, Y. . Visible light rewritable and long-lived colors in cholesteric liquid crystals: a facile co-doping strategy . Macromol. Rapid Commun. , 2019 . 40 1900037 DOI: 10.1002/marc.201900037 http://doi.org/10.1002/marc.201900037 .
Tochitsky, I.; Kienzler, M. A.; Isacoff, E.; Kramer, R. H. . Restoring vision to the blind with chemical photoswitches . Chem. Rev. , 2018 . 118 10748 - 10773 . DOI: 10.1021/acs.chemrev.7b00723 http://doi.org/10.1021/acs.chemrev.7b00723 .
Dudek, M.; Deiana, M.; Pokladek, Z.; Pawlik, K.; Matczyszyn, K. . Reversible photocontrol of DNA melting by visible-light-responsive F4-coordinated azobenzene compounds . Chem. Eur. J. , 2018 . 24 18963 - 18970 . DOI: 10.1002/chem.201803529 http://doi.org/10.1002/chem.201803529 .
Jia, S.; Fong, W. K.; Graham, B.; Boyd, B. J. . Photoswitchable molecules in long-wavelength light-responsive drug delivery: from molecular design to applications . Chem. Mater. , 2018 . 30 2873 - 2887 . DOI: 10.1021/acs.chemmater.8b00357 http://doi.org/10.1021/acs.chemmater.8b00357 .
Weis, P.; Wu, S. . Light-switchable azobenzene-containing macromolecules: from UV to near infrared . Macromol. Rapid Commun. , 2018 . 39 1700220 DOI: 10.1002/marc.201700220 http://doi.org/10.1002/marc.201700220 .
Samanta, S.; Beharry, A. A.; Sadovski, O.; McCormick, T. M.; Babalhavaeji, A.; Tropepe, V.; Woolley, G. A. . Photoswitching azo compounds in vivo with red light . J. Am. Chem. Soc. , 2013 . 135 9777 - 9784 . DOI: 10.1021/ja402220t http://doi.org/10.1021/ja402220t .
Cheng, W.; Zhao, D.; Qiu, Y.; Hu, H.; Wang, H.; Wang, Q.; Liao, Y.; Peng, H.; Xie, X. . Robust multi-responsive supramolecular hydrogel based on a mono-component host-guest gelator . Soft Matter , 2018 . 14 5213 - 5221 . DOI: 10.1039/C8SM00639C http://doi.org/10.1039/C8SM00639C .
Hu, H.; Qiu, Y.; Wang, J.; Zhao, D.; Wang, H.; Wang, Q.; Liao, Y.; Peng, H.; Xie, X. . Photomodulated morphologies in halogen bond-driven assembly during gel-sol transition . Macromol. Rapid Commun. , 2019 . 40 1800629 DOI: 10.1002/marc.201800629 http://doi.org/10.1002/marc.201800629 .
Wang, J.; Hao, X.; Yan, H.; Jiang, Q.; Peng, H.; Xiong, B.; Liao, Y.; Xie, X. . Hydrogen bond driven self-supporting organogels from main-chain liquid crystalline polymers . Polymer , 2020 . 188 122148 DOI: 10.1016/j.polymer.2019.122148 http://doi.org/10.1016/j.polymer.2019.122148 .
Wang, J.; Jiang, Q.; Hao, X.; Yan, H.; Peng, H.; Xiong, B.; Liao, Y.; Xie, X. . Reversible photo-responsive gel-sol transitions of robust organogels based on an azobenzene-containing main-chain liquid crystalline polymer . RSC Adv. , 2020 . 10 3726 - 3733 . DOI: 10.1039/C9RA10161F http://doi.org/10.1039/C9RA10161F .
Yan, H.; Qiu, Y.; Wang, J.; Jiang, Q.; Wang, H.; Liao, Y.; Xie, X. . Wholly visible-light-responsive host-guest supramolecular gels based on methoxy azobenzene and β -cyclodextrin dimers . Langmuir , 2020 . 36 7408 - 7417 . DOI: 10.1021/acs.langmuir.0c00964 http://doi.org/10.1021/acs.langmuir.0c00964 .
Jiang, Q.; Zhao, D.; Wang, J.; Yan, H.; Cao, S.; Qiu, Y.; Wang, H.; Liao, Y.; Xie, X. . Light regulation and long-lived stability of RGB colors in cholesteric liquid crystal physical gels via a mixing strategy . Soft Matter , 2021 . 17 3216 - 3221 . DOI: 10.1039/D0SM02283G http://doi.org/10.1039/D0SM02283G .
Leeuwen, T. v.; Pijper, T. C.; Areephong, J.; Feringa, B. L.; Browne, W. R.; Katsonis, N. . Reversible photochemical control of cholesteric liquid crystals with a diamine-based diarylethene chiroptical switch . J. Mater. Chem. , 2011 . 21 3142 - 3146 . DOI: 10.1039/c0jm03626a http://doi.org/10.1039/c0jm03626a .
Li, Q.; Li, L.; Kim, J.; Park, H.; Williams, J. . Reversible photoresponsive chiral liquid crystals containing a cholesteryl moiety and azobenzene linker . Chem. Mater. , 2005 . 17 6018 - 6021 . DOI: 10.1021/cm051404z http://doi.org/10.1021/cm051404z .
White, T. J.; Cazzell, S. A.; Freer, A. S.; Yang, D. K.; Sukhomlinova, L.; Su, L.; Kosa, T.; Taheri, B.; Bunning, T. J. . Widely tunable, photoinvertible cholesteric liquid crystals . Adv. Mater. , 2011 . 23 1389 - 1392 . DOI: 10.1002/adma.201003577 http://doi.org/10.1002/adma.201003577 .
Peng, H.; Ni, M.; Bi, S.; Liao, Y.; Xie, X. . Highly diffractive, reversibly fast responsive gratings formulated through holography . RSC Adv. , 2014 . 4 4420 - 4426 . DOI: 10.1039/C3RA45570J http://doi.org/10.1039/C3RA45570J .
Yagai, S.; Kitamura, A. . Recent advances in photoresponsive supramolecular self-assemblies . Chem. Soc. Rev. , 2008 . 37 1520 - 1529 . DOI: 10.1039/b703092b http://doi.org/10.1039/b703092b .
White, T. J.; Natarajan, L. V.; Tondiglia, V. P.; Lloyd, P. F.; Bunning, T. J.; Guymon, C. A. . Monomer functionality effects in the formation of thiol-ene holographic polymer dispersed liquid crystals . Macromolecules , 2007 . 40 1121 - 1127 . DOI: 10.1021/ma061829m http://doi.org/10.1021/ma061829m .
White, T. J.; Liechty, W. B.; Natarajan, L. V.; Tondiglia, V. P.; Bunning, T. J.; Guymon, C. A. . The influence of N -vinyl-2-pyrrolidinone in polymerization of holographic polymer dispersed liquid crystals (HPDLCs) . Polymer , 2006 . 47 2289 - 2298 . DOI: 10.1016/j.polymer.2006.01.030 http://doi.org/10.1016/j.polymer.2006.01.030 .
Jin, O.; Fu, D.; Ge, Y.; Wei, J.; Guo, J. . Hydrogen-bonded chiral molecular switches: photo- and thermally-reversible switchable full range color in the self-organized helical superstructure . New J. Chem. , 2015 . 39 254 - 261 . DOI: 10.1039/C4NJ01538J http://doi.org/10.1039/C4NJ01538J .
Chen, S. H.; Wu, J. J. . Divergence of cholesteric pitch near the smectic-A transition in some cholesteryl nonanoate binary mixtures . Mol. Cryst. Liq. Cryst. , 1982 . 87 197 - 209 . DOI: 10.1080/00268948208084442 http://doi.org/10.1080/00268948208084442 .
McMillan, W. L. . X-ray scattering from liquid crystals. I. Cholesteryl nonanoate and myristate . Phys. Rev. A , 1972 . 6 936 - 947 . .
Takahashi, A.; Mallia, V. A.; Tamaoki, N. . Novel supramolecular hydrogen-bonded cholesteric mesogens: liquid crystalline, thermoptical and glass-forming properties . J. Mater. Chem. , 2003 . 13 1582 - 1587 . DOI: 10.1039/b302198j http://doi.org/10.1039/b302198j .
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