Fast event-based electron counting for small-mol­ecule structure determination by MicroED

Fast readout event-based electron counting (EBEC) is a promising detection strategy to determine accurate ab initio structures of beam-sensitive small mol­ecules by MicroED. A fast EBEC approach enhances the dynamic range of MicroED data by limiting the likelihood of coincidence loss (CL) – the undercounting of electrons due to their spatially and temporally unresolved arrival on a direct electron detector. As implemented by new counting detectors, fast EBEC allows structure-worthy data sets to be captured from individual small-mol­ecule crystals in under a minute.

Magnesium and potassium scorpionate com­plexes based on di­hydro­bis­(pyrazol­yl)borate

Analysis of the crystal structure of [di­hydro­bis­(pyrazol-1-yl)borato]tris­(tetra­hydro­furan)magnesium(II) tetra­benzyl­borate reveals a pronounced boat-shaped central Mg(N–N)₂B moiety with a weak pseudo-axial B—H⋯Mg inter­action. A novel counter-ion, [B(C₇H₇)₄)]⁻, has been obtained by the reaction between KBH₄ and (PhCH₂)MgCl to produce a polymeric potassium tetra­benzyl­borate with predominant (η⁶-C₆H₅)⋯K and (η³-C₆H₅)⋯K inter­actions.

Two nonlinear optically responsive crown ether inclusion com­pounds based on a sulfonimide anion assembly

Two novel benzyl­amine-based crown ether inclusion com­plexes have been synthesized and they exhibit nonlinear optical properties. Notably, [(C₆H₅–CH₂–NH₃)(18-crown-6)][TfNMs] [TfNMs = methyl­sulfon­yl)(tri­fluoro­meth­ylsulfon­yl)azanide] represents the first example of an 18-crown-6 com­plex with TfNMs as the counter-ion, enriching the family of crown ether inclusion com­plexes.

Rb₂Ca₂Si₂O₇: a new alkali alkaline-earth silicate based on [Si₂O₇]⁶⁻ anions

The crystal structure and thermal expansion of Rb₂Ca₂Si₂O₇ have been investigated from single-crystal diffraction data. The structural relationships with other pyrosilicates are discussed.

Synthesis, crystal structure elucidation, theoretical characterization and thermochemistry analysis of the potential anti­cancer drug BFS

A new crystal structure of the fluorine analogue of busulfan was ob­tained and analyzed using single-crystal X-ray diffraction and various com­putational methods. The crystal structure is stabilized by, among other factors, hy­dro­gen bonds, as confirmed by density functional theory calculations.

Synthesis and crystal structure of a nickel(II) 2′-de­oxy-6-thio­guanosine nitrate com­plex

The cationic tris-com­plex [Ni^II(d-tG)₃]²⁺ features bidentate N,S-chelating ligands in a distorted fac-S₃N₃ octa­hedral geometry with one Δ and two Λ isomers observed in the three independent cations, each with crystallographic threefold rotation symmetry.