10.1002/chem.202001051
Chemistry - A European Journal
COMMUNICATION
6596; f) W. Cheng, Y. Liu, in Biopolymer-Based Composites
(Eds.: S. Jana, S. Maiti, S. Jana), Woodhead Publishing, 2017,
pp. 31-60.
In conclusion, we have shown that the pathway dependence
is applicable to the redox-driven gels by utilizing a Fe(II)/Fe(III)
redox-based metal-organic gel system. To establish this, we
utilize dynamic imine bond formation between an aldehyde (1)
and an amine (2) as the key chemical reaction and incorporated
Fe(II) ions into the gel medium during the self-assembly process.
Significantly, direct preparation of the Fe(III)-gel from the mixture
of 1, 2 and Fe(III) ions is not feasible in our case. However, in situ
oxidation of the Fe(II) ions by various oxidising agent results in
conversion to a Fe(III)-organic gel, where the material properties
like gel stiffness, gel strength, swelling etc. can be controlled just
by controlling the rate of oxidation of the Fe(II) ions. We
established that the rate of formation of Fe(III) ions actually
determines the extent of intermolecular interactions whether to
produce gels or precipitations. Hence, for the Fe(III)-metallogels,
which cannot be prepared directly, we can achieve those gel
states in an indirect way by employing a redox reaction. We
envisage that, our approach will open up opportunities to
construct new functional redox gels.
[5] a) S. Ahmed, A. Chatterjee, K. Das, D. Das, Chem. Sci. 2019,
10, 7574-7578; b) S. Dhiman, K. Jalani, S. J. George, ACS Appl.
Mater. Inter. 2019; c) Y. Che, S. Zschoche, F. Obst, D.
Appelhans, B. Voit, J. Polym. Sci., A Polym. Chem. 2019, 57,
2590-2601; d) W. A. Ogden, Z. Guan, ChemSystemsChem
2019, 1, e1900030; e) X. Sui, X. Feng, M. A. Hempenius, G. J.
Vancso, J. Mater. Chem. B 2013, 1, 1658-1672; f) F. Peng, G.
Li, X. Liu, S. Wu, Z. Tong, JACS 2008, 130, 16166-16167; g) J.
P. Wojciechowski, A. D. Martin, P. Thordarson, J. Am. Chem.
Soc. 2018, 140, 2869-2874.
[6] R. Eelkema, A. Pich, Adv. Mater. 2020, 1906012.
[7] a) J. Raeburn, A. Zamith Cardoso, D. J. Adams, Chem. Soc.
Rev. 2013, 42, 5143-5156; b) S. Panja, B. Dietrich, D. J. Adams,
ChemSystemsChem 2020, 2, e1900038; c) E. R. Draper, D. J.
Adams, Langmuir 2019, 35, 6506-6521; d) S. Panettieri, R. V.
Ulijn, Curr. Op. Struct. Biol. 2018, 51, 9-18.
[8] a) C. B. Minkenberg, W. E. Hendriksen, F. Li, E. Mendes, R.
Eelkema, J. H. van Esch, Chem. Commun. 2012, 48, 9837-
9839; b) T. Jiao, G. Wu, Y. Zhang, L. Shen, Y. Lei, C.-Y. Wang,
A. C. Fahrenbach, H. Li, Angew. Chem. Int. Ed. 2020, doi:
10.1002/anie.201910739.
Experimental Section
[9] V. Saggiomo, U. Lüning, Tet. Lett. 2009, 50, 4663-4665.
[10] J. T. Auletta, G. J. LeDonne, K. C. Gronborg, C. D. Ladd, H. Liu,
W. W. Clark, T. Y. Meyer, Macromolecules 2015, 48, 1736-1747.
[11] A. Panja, K. Ghosh, Mater. Chem. Frontiers 2018, 2, 1866-1875.
[12] R. K. Grötsch, C. Wanzke, M. Speckbacher, A. Angı, B. Rieger,
J. Boekhoven, J. Am. Chem. Soc. 2019, 141, 9872-9878.
[13] S. Panja, D. J. Adams, Chem. Commun. 2019, 55, 10154-10157.
[14] a) D.-J. Kim, D. Pradhan, K.-H. Park, J.-G. Ahn, S.-W. Lee,
Mater. Trans. 2008, 49, 2389-2393; b) M. S. Ibrahim, A. H.
Gemeay, S. E.-d. H. Etaiw, Transition Met. Chem. 2001, 26, 44-
49.
See Supporting Information for full details.
Acknowledgements
S.P. thanks the Royal Society and SERB of India for a Newton
International Fellowship. D.A. thanks the EPSRC for a Fellowship
(EP/L021978/1). The authors thank Dr. Bart Dietrich and
Valentina Gauci for NMR and HRMS experiments.
[15] a) K. Krishnamurti, Nature 1929, 123, 242-243; b) J. Singh, M.
E. Weber, Chem. Eng. Sci. 1996, 51, 4499-4508.
Keywords: Supramolecular gel • Metal-organic gel • Kinetic
control • Pathway dependence • Redox responsiveness •
Swelling
[1] a) P. Dastidar, Gels 2019, 5, 15; b) T. Christoff-Tempesta, A. J.
Lew, J. H. Ortony, Gels 2018, 4, 40; c) N. Mehwish, X. Dou, Y.
Zhao, C.-L. Feng, Materials Horizons 2019, 6, 14-44; d) J. Li, L.
Geng, G. Wang, H. Chu, H. Wei, Chem. Mater. 2017, 29, 8932-
8952; e) J. Li, R. Xing, S. Bai, X. Yan, Soft Matter 2019; f) Y. Li,
D. J. Young, X. J. Loh, Materials Chemistry Frontiers 2019, 3,
1489-1502.
[2] a) P. Dastidar, S. Ganguly, K. Sarkar, Chemistry – An Asian
Journal 2016, 11, 2484-2498; b) H. Wu, J. Zheng, A.-L.
Kjøniksen, W. Wang, Y. Zhang, J. Ma, Adv. Mater. 2019, 31,
1806204; c) S. Xiao, P. J. Paukstelis, R. D. Ash, P. Y. Zavalij, J.
T. Davis, Angew. Chem. Int. Ed. 2019, 58, 18434-18437.
[3] a) A. Panja, K. Ghosh, New J. Chem. 2019, 43, 934-945; b) A.
J. McConnell, C. S. Wood, P. P. Neelakandan, J. R. Nitschke,
Chem. Rev. 2015, 115, 7729-7793.
[4] a) C. Echeverria, S. N. Fernandes, M. H. Godinho, J. P. Borges,
P. I. P. Soares, Gels 2018, 4, 54; b) M. D. Segarra-Maset, V. J.
Nebot, J. F. Miravet, B. Escuder, Chem. Soc. Rev. 2013, 42,
7086-7098; c) G. R. Deen, X. J. Loh, Gels 2018, 4, 13; d) P. K.
Bolla, V. A. Rodriguez, R. S. Kalhapure, C. S. Kolli, S. Andrews,
J. Renukuntla, J. Drug Delivery Sci. Techn. 2018, 46, 416-435;
e) C. D. Jones, J. W. Steed, Chem. Soc. Rev. 2016, 45, 6546-
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