On the SHELX, PLATON and IUCr/checkCIF crystal structure validation platform

With checkCIF the IUCr has created a unique platform for the validation and archiving of the result of a small-mol­ecule crystal structure study.

Are crystal structures getting better? A temporal and elemental analysis of the Cambridge Structural Database

A statistical evaluation of the entries in the Cambridge Structural Database reveals trends in structural quality as described by the accessible quality indicators in the CSD with respect to the structures' publication year and the elements contained.

Eu₅Ga₂As₆ and Ba₅In₂As_6–xSb_x: new As-containing members of the Sr₅Al₂Sb₆ structure type

The first As-containing representatives of the Sr₅Al₂Sb₆ structure type are reported. The anionic sub­structures in Eu₅Ga₂As₆ and Ba₅In₂As_6–xSb_x [x = 0.49 (2) and 2.92 (2)] com­prise 1D chains of corner- and edge-sharing [TrPn₄] tetra­hedra with pendant [Pn₂] dumbbells (Tr = Ga, In; Pn = As, Sb). The mixed-pnictogen phases reveal site-selective As/Sb substitution as a potential route for tuning the bonding and physical properties of this family.

Solvent-free thallium(I) tetra­kis­[3,5-bis­(tri­fluoro­meth­yl)phen­yl]borate: crystal structure, supra­molecular inter­actions and anisotropic thermal expansion

The solvent-free structure of the thallium(I) salt of the weakly coordinating anion tetra­kis­[3,5-bis­(tri­fluoro­meth­yl)phen­yl]borate, Tl[BC₃₂H₁₂F₂₄], exhibits short Tl⋯F contacts and a supra­molecular architecture governed by C—H⋯F hy­dro­gen bonds and weak F⋯F and C—F⋯π inter­actions. Disorder and tilting of the arene rings generate different close-contact motifs, giving rise to hinge-like inter­molecular inter­actions and pronounced anisotropic thermal expansion along the crystallographic a and b axes.

Crystal structure of fucoxanthin: resolving a long-standing crystallographic challenge

The first small-mol­ecule single-crystal X-ray structure of fuco­xanthin is reported, resolving a long-standing crystallographic problem in carotenoid structural chemistry.

Synthesis of a phenazine radical anion com­plex: structural and spectroscopic analysis of spin delocalization

The crystallographic bond metrics of a 1:1 cocrystal containing a potassium–phenazine adduct and a phenazine-bridged homobimetallic zinc(II) com­plex indicate that the bimetallic zinc com­ponent is singly reduced. However, the solution-state electron paramagnetic resonance of this system indicates two distinct phenazine radical environments.

Hydrogen bonding in cocrystals of trans-Ni^II(hfac)₂(H₂O)₂

Two cocrystals of trans-Ni^II(hfac)₂(H₂O)₂ con­taining cocrystallized water or 1,2-di­meth­oxy­ben­zene were characterized by single-crystal X-ray diffraction. The hy­dro­gen-bonding networks in each cocrystal were com­pared to previously reported structures, revealing that Ni^II(hfac)₂(H₂O)₂ is capable of forming a variety of hy­dro­gen-bond network motifs depending on the nature of the coformers in the crystal structure. Cocrystallization of 1,2-di­meth­oxy­ben­zene was found to inhibit the formation of extended hy­dro­gen-bond networks.

Conformation and supra­molecular assembly in an azo–azomethine–pyrazole hybrid: crystal structure, Hirshfeld surface and QTAIM analyses

An azo–azomethine–pyrazole donor–π–acceptor hybrid crystallizes with two independent mol­ecules (Z′ = 2) linked through a co-operative network of O—H⋯N, C—H⋯O and C—H⋯N inter­actions. Hirshfeld surface and QTAIM analyses reveal the hierarchical contribution of strong and weak noncovalent inter­actions to the conformational stabilization and supra­molecular assembly of the crystal structure.

Uranyl derivatives: discovering features by com­paring related crystal structures

A brief overview of the existing data on related UO₂²⁺-containing crystal structures uncovered some peculiarities about three new derivatives. The first crystal structure with simultaneously present H₃O⁺ and Be²⁺ cations was solved. The rigidity of topology to the change of the nature of the fragments and ways to control the atom environment via the ratio of the reagents are discussed.

Synthesis and crystal structure characterization of Na[Fe₄S₃(NO)₇]·5H₂O

The title com­pound is a hydrated sodium salt of a nitrosyl iron–sulfur cluster. While retaining the typical [Fe₄S₃(NO)₇]⁻ core framework, a unique one-dimensional hy­dro­gen-bonded supra­molecular network is formed induced by Na⁺. The refinement process properly handled the 60° rotational disorder phenomenon of the anion in this structure.

Miro­gabalin, C₁₂H₁₉NO₂, and miro­gabalin besylate, C₁₂H₂₀NO₂⁺·C₆H₅O₃S⁻

The crystal structures of miro­gabalin and miro­gabalin besylate have been solved and refined using synchrotron powder X-ray diffraction data, and optimized using density functional theory techniques.

Crystal structure, inter­molecular inter­actions, Hirshfeld surface analysis, theoretical studies and biological evaluation of (E)-5-(benz­yloxy)-2-{[(2,5-di­meth­oxy­phen­yl)imino]­meth­yl}phenol, a new Schiff base

The title Schiff base com­pound was synthesized by the reaction of 4-(benz­yloxy)-2-hy­droxy­benzaldehyde and 2,4-di­meth­oxy­aniline in a 1:1 ratio. In the crystal, there are two independent mol­ecules in the asymmetric unit and both mol­ecules were refined as having a mixture of the imino–phenol and iminio–phenolate tautomeric forms. The com­pound exhibits significant inhibition properties.

Synthesis, crystal structure, Hirshfeld surface analysis and halogen-involving inter­actions in a bromo/chloro-substituted Schiff base 1-(3-bromo-4,5-di­meth­oxy­phen­yl)-N-(2,4-di­chloro­phen­yl)methanimine

Halogen substitution within a Schiff base induces a twisted mol­ecular conformation with an E configuration around the C=N bond, which strongly influences the supra­molecular assembly. The results provide insight into how mol­ecular design can control both the conformation and packing of halogen-substituted Schiff bases, offering avenues for the development of functional materials.

Experimental and theoretical investigation of a 5-iodo-6-methyl­uracil derivative as a key inter­mediate for Elagolix synthesis: crystal structure, Hirshfeld surface analysis and DFT calculations

The crystal structure of a key inter­mediate for Elagolix synthesis was determined and systematically investigated. Structural analysis indicates that the mol­ecule adopts a noticeably twisted `V'-shaped conformation. Weak inter­action analyses and 3D energy frameworks demonstrate that the supra­molecular network is co-operatively maintained by classical N—H⋯O hy­dro­gen bonds and predominant inter­molecular dispersion forces.