XFEL Microcrystallography of Self-Assembling Silver n-Alkanethiolates

Abstract

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 nnonanethiolate (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 evennumbered 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.

Inorganic–Organic Hybrid Layered Semiconductor AgSePh: Quasi-Solution Synthesis, Optical Properties, and Thermolysis Behavior

“…Similar trends in solubility and T m are present in another MOC familyelectrically neutral metal 1-alkanethiolates (M­(SR) m ; alkyl R = C n H 2 n +1 , m = 1–4, denoting the oxidation state of metals). Univalent silver 1-alkanethiolates (AgSR) have been accepted to display 2D layered polymeric structures, , high T m (>130 °C for AgSR) , and insolubility in common organic solvents. ,, However, AgSR (R = C n H 2 n +1 ; n = 4, 6–18) was suggested to be dissoluble in hot toluene at ∼100–105 °C. , The dissolution in hot toluene could be triggered by the degradation of the layered polymeric structure to the oligomeric fragments, for example, the columnar (micellar) mesophase . The dissolved species should not be AgSR monolayers.…”

“…40 Similar trends in solubility and T m are present in another MOC family�electrically neutral metal 1-alkanethiolates (M(SR) m ; alkyl R = C n H 2n+1 , m = 1−4, denoting the oxidation state of metals). Univalent silver 1-alkanethiolates (AgSR) have been accepted to display 2D layered polymeric structures, 6,41 high T m (>130 °C for AgSR) 42,43 and insolubility in common organic solvents. 6,42,43 However, AgSR (R = C n H 2n+1 ; n = 4, 6−18) was suggested to be dissoluble in hot toluene at ∼100− 105 °C.…”

Kilohertz droplet-on-demand serial femtosecond crystallography at the European XFEL station FXE

“…To identify “hot pixels” on the LPD, as previously reported by Aleksich et al , 57 a series of masking procedures was performed. Briefly, before data collection, a crude mask was created based on peakfinder results from water and lysozyme crystals to eliminate peaks significantly above the average occurrence.…”

XFEL Beamline Optical Instrumentation for Ultrafast Science

“…An example is a recent high-resolution (1.35 Å) ultrafast optical control TR-SFX experiment, which assigned contributions from coherent motion . Recently, TR-SFX has moved to the chemical domain. − …”