Communication
RSC Advances
to perylene core resulted in restricted molecular motion of the
hybrid and thus increased fluorescence anisotropy. The lower
anisotropy observed for PE-R (r = 0.031) could be due to higher
rotational diffusion (because of less rigid molecular environment)
that may occur during the lifetime of the excited state and
displaces the emission dipole of the fluorophore.
11 S. K. Gupta, V. A. Raghunathan and S. Kumar, New J. Chem.,
2009, 33, 112.
12 H. K. Bisoyi and S. Kumar, Tetrahedron Lett., 2008, 49, 3628.
13 S. K. Pal, S. Kumar and J. Seth, Liq. Cryst., 2008, 35, 521.
14 S. Setia, S. Sidiq and S. K. Pal, Tetrahedron Lett., 2012, 53, 6446.
15 G. Griffini, L. Brambilla, M. Levi, M. D. Zoppo and S. Turri, Dyes
Pigm., 2013, 111, 41.
1
6 X.-L. Zhang, J.-F. Song, X.-B. Li, J. Feng and H.-B. Sun, Org.
Electron., 2013, 14, 1577.
Conclusions
1
7 X. Chu, M. Guan, Y. Zhang, Y. Y. Li, X. F. Liu and Y. Zeng, RSC
Adv., 2013, 3, 9509.
In conclusion, a novel series of disc-rod oligomers have been
synthesized for the first time consisting of a perylene core attached
to which are four 4-cyanobiphenyl, triphenylene and cholesteryl
units via flexible alkyl spacers. Whereas, attachment of CB and Ch
units to the PE core leads to the formation of N and N* phase,
respectively, TP and simple alkyl chain resulted a regular
hexagonal mesophase. We have demonstrated that the combina-
tion of rod and disc-like moieties in the PE-CB and PE-Ch series
has sufficiently perturbed the molecular shape to yield calamitic
mesophases. Although biaxiality is likely to be seen at small length
scales, as a result of large aspect ratios between two components,
there is no direct evidence for the formation of biaxial N phase in
our study. In addition, we have shown that all the hybrid materials
exhibit excellent fluorescence emission properties making them
suitable for various opto-electronic applications. Such materials
combine an exceptionally high degree of self-organization at the
nanometer scale with the advantages that LCs provide.
1
8 M. Mosca, R. Macaluso, E. Feltin and C. Calii, Electron. Lett.,
012, 48, 1417.
9 A. Ringk, W. S. C. Roelofs, E. C. P. Smits, C. Van der Marel,
2
1
I. Salzmann, A. Neuhold, G. H. Gelinck, R. Resel, D. M. de
Leeuw and P. Strohriegl, Org. Electron., 2013, 14, 1297.
0 S. R. Puniredd, A. Kiersnowski, G. Battagliarin,
W. Zajaczkowski, W. W. H. Wong, N. Kirby, K. Mullen and
W. Pisula, J. Mater. Chem. B, 2013, 1, 2433.
2
21 C. T. Imrie, P. A. Henderson and G.-Y. Yeap, Liq. Cryst., 2009,
36, 755.
22 P. H. J. Kouwer, J. Pourzand and G. H. Mehl, Chem. Commun.,
2004, 66.
23 C. Zhang, Z. He, J. Wang, Y. Wang and S. Ye, J. Mol. Liq., 2008,
138, 93.
24 S. K. Pal and S. Kumar, Tetrahedron Lett., 2006, 47, 8993.
2
5 A. Marcelis, A. Koudijs, Z. Karczmarzyk and E. Sudh ¨o lter, Liq.
Cryst., 2003, 30, 1357.
2
6 T. Donaldson, H. Staesche, Z. B. Lu, P. A. Henderson, M.
F. Achard and C. T. Imrie, Liq. Cryst., 2010, 37, 1097.
Acknowledgements
2
7 H. Q. Zhang, W. K. Liu, L. C. Zhao, Z. H. Cheng, S. Zhang, Y. Li
and H. Yang, Chin. Chem. Lett., 2009, 20, 1077.
This work was carried out with the financial support from
IISER Mohali and Department of Science and Technology, Key
Project DST-12-0035 ‘‘Liquid Crystal Nanocrystal-A new
resource of functional soft materials for nanosciences’’. We
are grateful to NMR research facility at IISER Mohali for
recording NMR spectrum. We sincerely thank Ms. Shruti Arya
and Dr Samrat Mukhopadhyay for helping with fluorescence
measurements. S. Setia and S. Sidiq acknowledge the receipt of
a graduate fellowship from CSIR-NET and UGC-NET, respec-
tively.
28 N. Zheludev, Nat. Photonics, 2007, 1, 189.
29 C.-T. Chen, Chem. Mater., 2004, 16, 4389.
3
0 S. P. DenBaars, D. Feezell, K. Kelchner, S. Pimputkar, C.-C. Pan,
C.-C. Yen, S. Tanaka, Y. Zhao, N. Pfaff, R. Farrell, M. Iza,
S. Keller, U. Mishra, J. S. Speck and S. Nakamura, Acta Mater.,
2
013, 61, 945.
1 M. C. Gather, A. Kohnen and K. Meerholz, Adv. Mater., 2011, 23,
33.
2 D. F. Feezell, J. S. Speck, S. P. DenBaars and S. Nakamura, J.
Disp. Technol., 2013, 9, 190.
3
2
3
References
33 C.-K. Tan, J. Zhang, X.-H. Li, G. Liu, B. O. Tayo and N. Tansu, J.
Disp. Technol., 2013, 9, 272.
4 H. P. Zhao, G. Y. Liu, J. D. Poplawsky, V. Dierolf and N. Tansu,
Opt. Express, 2011, 19, A991.
1
2
C. Tschierske, J. Mater. Chem., 1998, 8, 1485.
G. Stebani, G. Lattermann, M. Wittenberg and J. H. Wendorff,
J. Mater. Chem., 1997, 7, 607.
C. Tschierske, Annu. Rep. Prog. Chem., Sect. C, 2001, 97, 191.
C. Tschierske, J. Mater. Chem., 2001, 11, 2647.
A. Pegenau, T. Hegmann, C. Tschierske and S. Diele, Chem.–
Eur. J., 1999, 5, 1643.
3
3
5 G. Liu, J. Zhang, C.-K. Tan and N. Tansu, IEEE Photonics J., 2013,
, 2201011.
6 J. Zhang and N. Tansu, IEEE Photonics J., 2013, 5, 2600111.
7 P. Zhu, G. Liu, J. Zhang and N. Tansu, J. Disp. Technol., 2013, 9,
17.
8 E. Matioli, S. Brinkley, K. M. Kelchner, Y.-L. Hu, S. Nakamura,
3
4
5
5
3
3
3
6
7
8
9
C. Zhang, Z. He, J. Wang, Y. Wang and S. Ye, J. Mol. Liq., 2008,
3
138, 93.
S. Denbaars, J. Speck and C. Weisbuch, Light: Sci. Appl., 2012, 1,
e22.
9 R. Alben, Phys. Rev. Lett., 1973, 30, 778.
0 R. Alben, J. Chem. Phys., 1973, 59, 4299.
1 J. P. Straley, Phys. Rev. A: At., Mol., Opt. Phys., 1974, 10, 1881.
2 F. Wurthner, Chem. Commun., 2004, 1564.
X. Kong, Z. He, Y. Zhang, L. Mu, C. Liang, B. Chen, X. Jing and
A. N. Cammidge, Org. Lett., 2011, 13, 764.
M. Bagui, T. Dutta, H. Zhong, S. Li and S. Chakraborty,
Tetrahedron, 2012, 68, 2806.
M. Bagui, T. Dutta, S. Chakraborty, J. S. Melinger, H. Zhong,
A. Keightley and Z. Peng, J. Phys. Chem. A, 2011, 115, 1579.
3
4
4
4
4
3 A. G. Vanakaras, M. A. Bates and D. J. Photinos, Phys. Chem.
Chem. Phys., 2003, 5, 3700.
10 Y.-F. Bai, K.-Q. Zhao, P. Hu, B.-Q. Wang and C. Redshaw, Curr.
Org. Chem., 2013, 17, 871.
1
2064 | RSC Adv., 2013, 3, 12060–12065
This journal is ß The Royal Society of Chemistry 2013