The Institute of Biological Chemistry invites to a seminar with

Dr. Giulia Mollica, Université D'Aix-Marseille, CNRS, Frankreich
 
Title: Solid-state NMR and DNP to investigate the formation and transformation of polymorphic solids

Abstract:

Crystallization plays an important role in many areas of biology, chemistry and materials science, but the underlying mechanisms that govern crystallization are still poorly understood because of experimental limitations in the analysis of such complex, evolving systems. To derive a fundamental understanding of crystallization processes, it is essential to access the sequence of solid phases produced as a function of time, with atomic-level resolution. Rationalization of crystallization processes is particularly relevant for polymorphic functional materials, for which manufacture or storage-induced, unexpected, polymorph transitions can compromise the end-use of the solid product. Interestingly, these transformations often imply the formation of metastable forms. Today, detection and accurate structural analysis of these – generally transient – forms remain challenging, essentially because of the present limitations in temporal and spatial resolution of the analysis. These experimental barriers prevent the rationalization – and hence the control – of crystallization processes.

I will discuss recent progress from our group showing that cryogenic MAS NMR combined with the sensitivity enhancement provided by dynamic nuclear polarization (DNP) can be an efficient way of monitoring the structural evolution of crystallizing solutions with atomic-scale resolution on a time scale of a few minutes. I will discuss current approaches and recent developments allowing to detect, stabilize, and characterize transient, metastable phases formed at the early stages of crystallization, as well as to identify and characterize the incipient emergence of new polymorphs, both in the bulk and under confinement [1-2].

This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (GA 758498)

 [1] Juramy, M., Chèvre, R., Cerreia-Vioglio, P., Ziarelli, F., Besson, E., Gastaldi, S., Viel, S., Thureau, P., Harris, K.D.M. & Mollica, G. (2021) J. Am. Chem. Soc.143, 6095.

[2] Cousin, S.F., Hughes, C.E., Ziarelli, F., Viel, S., Mollica, G., Harris, K.D.M., Pinon, A.C. & Thureau, P., (2023) Chem. Sci. 14, 10121.

Website: https://mollicalab.fr/