CataLight Research Seminar Winter Term 2024/2025

Teaching crystalline sponges new tricks

Dr. Simon Krause
Max-Planck-Institute for Solid State Research

Living matter is dynamic, responsive and vivid. Crystals and solids are perceived as rigid, brittle, and dead. What if we could teach solids tricks of living matter?

In this presentation I will demonstrate porous solids in which the pore walls exhibit (controllable) dynamic features. First, I will introduce “dynamic confinement” of soft porous crystals [1] in the form of pore contraction and/or expansion as response to the adsorption of gases and fluids. I will demonstrate molecular design principles for such dynamic porous solids and provide analytical tools that allow you to study host-guest interactions in parallel to pore deformation. [2] I will present the counterintuitive phenomena of negative gas adsorption as a result of dynamic pore deformation and provide a mechanism built on experimental and theoretical methods. [3] Secondly, I will introduce a concept that allows to trigger pore deformation by light-stimulation utilizing framework-embedded molecular photo-switches [4]. When applied in parallel to the adsorption of gases such materials exhibit light-responsive breathing of the pore space.

Finally, I will demonstrate “confined dynamics” as a concept that utilizes dynamic features of molecular machines in an otherwise rigid pore space. I will describe the incorporation and operation of unidirectional rotation of light-driven molecular motors in porous solids such as metal-organic or covalent organic frameworks. [5,6] I will provide a theoretical perspective on how such confined dynamics can activate, and direct adsorption and transport properties as a function of light stimulation and pore size and how we can realize such a system in reality. [7] Finally, I will present our vision on how we can alter these effects on the mesoscale and how they can result in functional dynamics that impact materials properties towards key physicochemical processes such as catalysis. [8]

References

[1]    S. Krause, N. Hosono, S. Kitagawa, Angew. Chem. Int. Ed. 2020, 59, 15325-15341.
[2]    a) S. Krause, J. D. Evans, V. Bon, I. Senkovska, P. Iacomi, F. Kolbe, S. Ehrling, E. Troschke, J. Getzschmann, D. M. Többens, A. Franz, D. Wallacher, P. G. Yot, G. Maurin, E. Brunner, P. L. Llewellyn, F.-X. Coudert, S. Kaskel, Nat. Commun. 2019, 10, 3632; b) S. Krause, J. D. Evans, V. Bon, I. Senkovska, S. Ehrling, P. Iacomi, D. M. Többens, D. Wallacher, M. S. Weiss, B. Zheng, P. G. Yot, G. Maurin, P. L. Llewellyn, F.-X. Coudert, S. Kaskel, Chem. Sci. 2020, 11, 9468-9479.
[3]    S. Krause, V. Bon, I. Senkovska, U. Stoeck, D. Wallacher, D. M. Többens, S. Zander, R. S. Pillai, G. Maurin, F.-X. Coudert, S. Kaskel, Nature 2016, 532, 348-352.
[4]    S. Krause*, J. D. Evans, V. Bon, S. Crespi, W. Danowski, W. R Browne, S. Ehrling, F. Walenszus, D. Wallacher, N. Grimm, D. D. Többens, M. S. Weiss, S. Kaskel, B. L. Feringa, Cooperative Light-Induced Breathing of Soft Porous Crystals via Azobenzene Buckling, Nat. Commun., 2022, 13, 1951.
[5]    W. Danowski, F. Castiglioni, A. S. Sardjan, S. Krause, L. Pfeifer, D. Roke, A. Comotti, W. R. Browne, B. L. Feringa, J. Am. Chem. Soc. 2020, 142, 9048-9056.
[6]    C. Stähler, L. Grunenberg, M. W. Terban, W. R. Browne, D. Doellerer, M. Kathan, M. Etter, B. V. Lotsch, B. L. Feringa, S. Krause*, Light-Driven Molecular Motors Embedded in Covalent Organic Frameworks, Chem. Sci., 2022, 13, 8253-8264.
[7]    J. D. Evans, S. Krause, B. L. Feringa, Faraday Discuss. 2021, 225, 286-300.
[8]    S. Krause, J. V. Milić, Commun Chem, 2023, 6, 151.