3D ED/MicroED entering a new era

Aragon et al. [Acta Cryst. (2024), C80, 179–189], by reporting the discussion and the final conclusions of a round table held during a symposium at the National Center for CryoEM Access and Training, well describe all the advances that have been made for the application of 3D ED/MicroED to pharmaceutical and macromolecular nanocrystals and propose possible future scenarios.

Applying 3D ED/MicroED workflows toward the next frontiers

This topical review highlights recent 3D ED/MicroED developments and serves as proceedings of a symposium and workshop held on November 6–9, 2023, at the National Center for CryoEM Access and Training in New York, New York, USA.

Mol­ecular structure and selective theophylline com­plexation by conformational change of di­ethyl N,N′-(1,3-phenyl­ene)dicarbamate

The diethyl N,N′-(1,3-phenyl­ene)dicarbamate–theophylline (1–TEO) com­plex was obtained by mechanochemistry involving the conformational change of one of the ethyl carbamate groups of 1 from the endo conformation to the exo conformation to allow the formation of inter­molecular inter­actions.

Synthesis, characterization and structural analysis of com­plexes from 2,2′:6′,2′′-terpyridine derivatives with transition metals

A series of com­pounds were synthesized from a 1:2 mixture of a metal and a terpyridine (TPY) ligand, with the general formula [M(R-TPY)₂](ClO₄)₂ (where M = Co²⁺, Fe²⁺, Mn²⁺ and Ni²⁺, and R-TPY = Ph-TPY, ClPh-TPY and MeOPh-TPY). All com­pounds were characterized spectroscopically and three, [Ni(Ph-TPY)₂](ClO₄)₂, [Mn(MeOPh-TPY)₂](ClO₄)₂ and [Mn(Ph-TPY)₂](ClO₄)₂, were determinated by single-crystal X-ray diffraction.

Crystal structures, electron spin resonance, and thermogravimetric analysis of three mixed-valence copper cyanide polymers

The crystal structures of three mixed-valence copper cyanide polymers with similar polymeric CuCN networks are described, together with the results of electron spin resonance and thermogravimetric analyses.

Relationship between synthesis method–crystal structure–melting properties in co­crystals: the case of caffeine–citric acid

A new polymorphic form of the caffeine–citric acid cocrystal, solved by powder X-ray diffraction thanks to synchrotron experiments, was com­pared with the already known forms. An analysis of the hydrogen bonding indicates that the cocrystal obtained here is less stable than the co­crystals already identified in the literature.

Synthesis, structure and photoluminescence properties of heterometallic-based coordination polymers of trimesic acid

Three heterometallic coordination polymers (CPs) have been synthesized and characterized, employing trimesic acid as the organic linker. Upon com­plexation with mixed metal ions, the doubly and fully deprotonated forms of the ligand exhibit distinct coordination modes, resulting in distinct structural dimensionalities of the final networks. One of the CPs is a promising candidate for targeted investigation as a luminescent sensor for the recognition and detection of small organic mol­ecules.

Supra­molecular hy­dro­gen-bonded networks formed from copper(II) car­box­ylate dimers

Outward-directing phenolic/phenolate groups on copper car­box­yl­ate dimers have a powerful structure-directing influence, leading to the generation of an assortment of hy­dro­gen-bonded networks.