XFEL Microcrystallography of Self-Assembling Silver n-Alkanethiolates

Mariya Aleksich, Daniel W. Paley, Elyse A. Schriber, Will Linthicum, Vanessa Oklejas, David W. Mittan-Moreau, Ryan P. Kelly, Patience A. Kotei, Anita Ghodsi, Raymond G. Sierra, Andrew Aquila, Frédéric Poitevin, Johannes P. Blaschke, Mohammad Vakili, Christopher J. Milne, Fabio Dall'Antonia, Dmitry Khakhulin, Fernando Ardana-Lamas, Frederico Lima, Joana Valerio, Huijong Han, Tamires Gallo, Hazem Yousef, Oleksii Turkot, Ivette Bermudez J. Macias, Thomas Kluyver, Philipp Schmidt, Luca Gelisio, Adam R. Round, Yifeng Jiang, Doriana Vinci, Yohei Uemura, Marco Kloos, Mark Hunter, Adrian P. Mancuso, Bryan D. Huey, Lucas R. Parent, Nicholas K. Sauter, Aaron S. Brewster, and Nathan J. Hohman

[BibTeX]doi:10.1021/jacs.3c02183

New synthetic hybrid materials and their increasing complexity have placed growing demands on crystal growth for single-crystal X-ray diffraction analysis. Unfortunately, not all chemical systems are conducive to the isolation of single crystals for traditional characterization. Here, small-molecule serial femtosecond crystallography (smSFX) at atomic resolution (0.833 Å) is employed to characterize microcrystalline silver n-alkanethiolates with various alkyl chain lengths at X-ray free electron laser facilities, resolving long-standing controversies regarding the atomic connectivity and odd–even effects of layer stacking. smSFX provides high-quality crystal structures directly from the powder of the true unknowns, a capability that is particularly useful for systems having notoriously small or defective crystals. We present crystal structures of silver n-butanethiolate (C4), silver n-hexanethiolate (C6), and silver n-nonanethiolate (C9). We show that an odd–even effect originates from the orientation of the terminal methyl group and its role in packing efficiency. We also propose a secondary odd–even effect involving multiple mosaic blocks in the crystals containing even-numbered chains, identified by selected-area electron diffraction measurements. We conclude with a discussion of the merits of the synthetic preparation for the preparation of microdiffraction specimens and compare the long-range order in these crystals to that of self-assembled monolayers.

Tags: European XFEL