Please d oC hn eo mt Ca do mj u ms t margins
Page 4 of 5
Journal Name
COMMUNICATION
S. Ghosh, Chem. Sci., 2016, 7, 1115–1120.DOI: 10.1039/D0CC03686B
. S. Herbst, B. Soberats, P. Leowanawat, M. Stolte, M. Lehmann and
F. Würthner, Nat. Commun., 2018, 9, 2646.
0 P. Sun, Q. Wu, X. Sun, H. Miao, W. Deng, W. Zhang, Q. Fan and W.
Huang, Chem. Commun., 2018, 54, 13395–13398.
explains the strong red-shift of the absorption band due to the
slipped-stack packing arrangement of BisSQ1 molecules (Figure
9
1
1
4
d) and the formation of lamellar sheets consisting of the
hydrophobic S-shaped BisSQ1 molecules and hydrophobic alkyl
chains and the stabilization of this nanosheet against
precipitation in the given solvent by solubilizing
oligoethyleneglycol chains protruding above and below the
sheet into the solvent phase.
1 M. Kasha, H. R. Rawls and M. Ashraf El-Bayoumi, Pure Appl. Chem.,
1
965, 11, 371−392.
1
1
2 F. C. Spano, Acc. Chem. Res., 2010, 43, 429−439.
3 Z. Chen, A. Lohr, C. R. Saha-Möller and F. Würthner, Chem. Soc.
Rev., 2009, 38, 564–584.
4 U. Rösch, S. Yao, R. Wortmann and F. Würthner, Angew. Chem.
Int. Ed., 2006, 45, 7026–7030.
Indeed, this two-dimensional sheet structure formation may be
considered as a major outcome of our study. Thus, whilst one-
dimensional aggregation of squaraines is typically governed by
dispersion forces, thereby affording co-facially stacked dyes with H-
type coupling, two-dimensional aggregation as directed with our
concept of extended bischromophores provides J-aggregates. This is
most likely induced by the structural distortion between the
chromophores with a similar brickwork type organization as
observed in many thin film squaraine aggregates.17−20 We also like to
emphasize that the aggregation process in our study was
accomplished in an organic solvent and not in water, where
hydrophobic effects play an important role and for which indeed
some larger colloidal squaraine aggregates showed J-type
1
1
1
1
1
1
2
5 J. J. Gassensmith, J. M. Baumes and B. D. Smith, Chem. Commun.,
2
009, 42, 6329–6338.
6 S. Sreejith, P. Carol, P. Chithra and A. Ajayaghosh, J. Mater. Chem.,
008, 18, 264–274.
2
7 M. Gsänger, E. Kirchner, M. Stolte, C. Burschka, V. Stepanenko, J.
Pflaum and F. Würthner, J. Am. Chem. Soc., 2014, 136, 2351–2362.
8 G. Chen, H. Sasabe, W. Lu, X.-F. Wang, J. Kido, Z. Hong and Y. Yang,
J. Mater. Chem. C, 2013, 1, 6547−6552.
9 K. C. Deing, U. Mayerhöffer, F. Würthner and K. Meerholz Phys.
Chem. Chem. Phys., 2012, 14, 8328–8334.
1
0,35,36, 37
features.
0 M. Schulz, M. Mack, O. Kolloge, A. Lützen and M. Schiek, Phys.
Chem. Chem. Phys., 2017, 19, 6996−7008.
In a particular nice but rather special case Belfield and co-
workers could direct such J-aggregation by the interaction of 21 Y. Zhang, B. Kim, S. Yao, M. V. Bondar and K. D. Belfield, Langmuir,
appended cationic pyridinium units by templating with
polyanionic poly(acryclic acid).
2013, 29, 11005−11012.
22 H. Chen, M. S. Farahat, K.-Y. Law and D. G. Whitten, J. Am. Chem.
Soc., 1996, 118, 2584–2594.
2
1
In conclusion, we have introduced a very simple but efficient
approach to direct squaraine dye aggregation in solution from
the very common cofacial stacking leading to H-type exciton
coupling to the more desired slipped-stack packing leading to J-
type exciton coupling by simply connecting two dyes in a head-
to-tail bischromophore structure. It will be interesting to see if
this simple concept can be applied also to other squaraines or
even to entirely different chromophores.
2
2
2
2
2
3 K. Jyothish, M. Hariharan and D. Ramaiah, Chem. Eur. J., 2007, 13,
944–5951.
4 U. Mayerhöffer and F. Würthner, Angew. Chem. Int. Ed., 2012, 51,
615–5619.
5
5
5 X. Zhang, Y. Wei, T. Bing, X. Liu, N. Zhang, J. Wang, J. He, B. Jin and
D. Shangguan, Sci. Rep., 2017, 7, 4766.
6 U. Mayerhöffer, M. Gsänger, M. Stolte, B. Fimmel and F.
Würthner, Chem. Eur. J., 2013, 19, 218–232.
7 H. Ceymann, A. Rosspeintner, M. H. Schreck, C. Mützel, A. Stoy, E.
Vauthey and C. Lambert, Phys. Chem. Chem. Phys. 2016, 18,
Conflicts of interest
There are no conflicts to declare.
1
6404−16413.
2
2
8 M. I. S. Röhr, H. Marciniak, J. Hoche, M. H. Schreck, H. Ceymann,
R. Mitric and C. Lambert, J. Phys. Chem. C, 2018, 122, 8082–8093.
9 C. Zhong, D. Bialas, C. J. Collison and F. C. Spano, J. Phys. Chem. C,
Notes and references
2
019, 123, 18734–18745.
3
3
0 F. Würthner, Acc. Chem. Res., 2016, 49, 868–876.
1 M. M. J. Smulders, M. M. L. Nieuwenhuizen, T. F. A. de Greef, P.
van der Schoot, A. P. H. J. Schenning, E. W. Meijer, Chem. Eur. J.,
‡
Aggregation of reference dye SQ1 is too weak to be observed in our
comparative concentration-dependent experiments (see Figure S4 in
the Supplementary Information).
2
010, 16, 362−367.
2 C. Rest, R. Kandanelli and G. Fernández, Chem. Soc. Rev., 2015, 44,
543–2572.
3 T. E. Kaiser, V. Stepanenko and F. Würthner, J. Am. Chem. Soc.,
009, 131, 6719–6732.
3
3
3
3
3
1
2
3
. E. E. Jelley, Nature, 1936, 138, 1009−1010.
2
. G. Scheibe, Angew. Chem., 1937, 50, 212−219.
. F. Würthner, T. E. Kaiser and C. R. Saha-Möller, Angew. Chem. Int.
Ed., 2011, 50, 3376−3410.
2
4 T. Brixner, R. Hildner, J. Köhler, C. Lambert and F. Würthner, Adv.
Energy Mater., 2017, 7, 1700236
5 R. S. Stoll, N. Severin, J. P. Rabe and S. Hecht, Adv. Mater., 2006,
4
5
. N. R. Ávila-Rovelo and A. Ruiz-Carretero, Organic Materials, 2020,
0
2, 047–063.
. C. Sun, B. Li, M. Zhao, S. Wang, Z. Lei, L. Lu, H. Zhang, L. Feng, C.
Dou, D. Yin, H. Xu, Y. Cheng and F. Zhang, J. Am. Chem. Soc., 2019,
1
8, 1271–1275.
6 T. Liu, X. Liu, Y. Zhang, M. V. Bondar, Y. Fang and K. D. Belfield, Eur.
1
41, 19221−19225.
6
7
. A. Löhner, T. Kunsel, M. I. S. Röhr, T. L. C. Jansen, S. Sengupta, F.
Würthner, J. Knoester, and J. Köhler, J. Phys. Chem. Lett., 2019, 10,
2
715−2724.
. Z. Chen, Y. Liu, W. Wagner, V. Stepanenko, X. Ren, S. Ogi and F.
Würthner, Angew. Chem. Int. Ed., 2017, 56, 5729−5733.
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 4
Please do not adjust margins