In and out: crystal engineering for reversible iodine uptake

Moghzi et al. [Acta Cryst. (2020), B76, 779–788] use the metalloligand approach to form a crystalline 3D metal–organic material with remarkable iodine sorption capacity.

Looking at local classical and quantum forces in stable crystals using multipole-model refined electron densities and orbital-free DFT approximations

By cleverly combining concepts and tools from different disciplines and by making use of the X-ray derived electron density, the balance of quantum and electrostatic local forces acting on electrons in stable crystals can now be analysed. This is illustrated for diamond and the NaCl crystal, in terms of a topological analysis of the scalar potentials associated to these forces.

Three different Ge environments in a new Sr₅CuGe₉O₂₄ phase synthesized at high pressure and high tem­per­ature

The high-pressure/high-tem­per­ature phase Sr₅CuGe₉O₂₄ was solved by low-dose electron diffraction tomography and refined against powder X-ray diffraction data. The Ge ions in this compound have three different coordination numbers.

On the crystal structures and phase transitions of hydrates in the binary di­methyl sulfoxide–water system

The crystal structures of DMSO trihydrate and DMSO dihydrate have been determined, and a second metastable dihydrate has also been identified. The transformations between these phases, as well as their partial melting, allow us to interpret conclusively studies of the binary DMSO–water phase diagram that have been reported in the literature.

Morphology of the GdVO₄ crystal: first-principles studies

This paper reports first-principles density functional theory calculations to predict the crystal growth morphology and equilibrium shape of GdVO₄ crystal. The Bravais–Friedel–Donnay–Harker method, the attachment energy method and the surface energy method, in the frame of a 2D periodic slab model, were used.

Mechanistic insights into defect generation and tuning of optical properties in Zn_1−xFe_xAl₂O₄ (0.01 ≤ x ≤ 0.40) nanocrystals

The complex cation distribution in ZnAl₂O₄ upon Fe addition is probed, influencing defect annihilation and generation accompanied by modification of optical and magnetic properties.

Orbital-free quantum crystallography: view on forces in crystals

The spatial distribution of electrostatic and quantum electronic forces in stable crystals is studied using the experimental electron density and their structure-forming properties are revealed.

0D to 3D Pr^III metal–organic networks crystal engineered for optimal iodine adsorption

Crystal engineering techniques have been used successfully to design and synthesize four 0D to 3D praseodymium(III) metal–organic compounds. The results confirm the remarkable potential of one of the compounds for the reversible adsorption of iodine vapour (about 490 mg g⁻¹).

New examples of non-cooperative octahedral tilting in a double perovskite: phase transitions in K₃GaF₆

Three new polymorphs of K₃GaF₆ are observed at different temperatures.

High-pressure preference for reduced water content in porous zinc aspartate hydrates

The zinc aspartate complex, commonly used as a dietary supplement, crystallizes as either the dihydrate or the sesquihydrate. High pressure favours the sesquihydrate, and this has been rationalized by measurements of the compressibility using single-crystal X-ray diffraction up to 4 GPa.

The X-ray constrained wavefunction of the [Mn(CO)₄{(C₆H₅)₂P-S-C(Br₂)-P(C₆H₅)₂}]Br complex: a theoretical and experimental study of dihalogen bonds and other noncovalent interactions

The topology of the C—Br⋯Br dihalogen bond present in the title complex, as well as that of several noncovalent intramolecular C—H⋯Br—C interactions, have been studied from the point of view of the QTAIM and ELF methodologies applied to an X-ray constrained wavefunction.

C₆₀ in a peptidic cage: a case of symmetry mismatch studied by crystallography and solid-state NMR

A molecular container with C₆₀ cargo was crystallized and studied by X-ray diffraction revealing a complicated dis­order of the ligand caused by the incompatibility with its site symmetry. The tumbling of the C₆₀ cargo was studied by solid-state NMR which suggested possible phase transitions, positively verified at high temperature by DSC.

Nickel(II) com­plexes based on L-amino-acid-derived ligands: synthesis, characterization and study of the role of the supramolecular structure in carbon dioxide capture

Two L-amino-acid-based Ni^II com­plexes are reported; while the L-tyrosine derivative is a symmetrical μ₃-carbonate-bridged self-assembled trinuclear Ni^II com­plex whose formation involves CO₂ uptake, the L-phenyl­alanine analog is a mononuclear system which does not exhibit the same behaviour.

A new Tl_4.86Fe_0.82Hf_1.18(MoO₄)₆ ternary molybdate: crystal structure and properties

Single crystals of Tl_4.86Fe_0.82Hf_1.18(MoO₄)₆ were obtained by the self-flux method from high-temperature solutions in the Tl₂MoO₄–Fe₂(MoO₄)₃–Hf(MoO₄)₂ system. The crystal structure consists of nonpolar and polar domains with different local symmetries and can be described as a whole by the nonstandard space group R1 with local symmetry Rc for some atoms.

Five concomitant polymorphs of a green fluorescent protein chromophore (GFPc) analogue: understanding variations in photoluminescence with π-stacking interactions

A synthetically modified GFPc analogue, 3,4,5-tri­meth­oxybenzyl­idene imidazolinone, yielded five polymorphs concomitantly solely due to the interplay of iso-energetic weak intermolecular interactions in molecular associations. The different fluorescence emissions of Form I (blue) and Forms II to V (yellow) were attributed to the differences in π-stacking interactions.

A re-interpretation of the structure of the silver borate, Ag₁₆B₄O₁₀, in the light of the extended Zintl–Klemm concept

The structure of Ag₁₆B₄O₁₀ is re-interpreted according to the extended Zintl–Klemm concept. The [B₄O₁₀]⁸⁻ anions (isostructural to P₄O₁₀) are reformulated as Ψ-N₄O₁₀, making sense of its similarity to P₄O₁₀. The excess of 8 e⁻, previously located at Ag₄ voids, should be distributed through Ag—O interactions.

Twinning in SnO₂-based ceramics doped with CoO and Nb₂O₅: morphology of multiple twins revealed by electron backscatter diffraction

The MTEX procedure for electron backscatter diffraction data treatment allows automated detection of cyclic twins with coplanar and alternating morphology in sintered cassiterite-based ceramics.

Li₄Ru₂OCl₁₀·10H₂O: crystal structure, magnetic properties and bonding interactions in ruthenium-oxo complexes

In this work, a new ruthenium-oxo compound is discovered and the crystal structure and magnetic properties are examined.

Structural variety of heterosynthons in linezolid cocrystals with modified thermal properties

Mechanochemical grinding led to the formation of five new cocrystals of linezolid. The analysis of their crystal structures revealed a variety of supramolecular synthons, with no clear preferences towards the formation of particular intermolecular interactions.

Triple molybdates K_3–xNa_1+xM₄(MoO₄)₆ (M = Ni, Mg, Co) and K_3+xLi_1–xMg₄(MoO₄)₆ isotypic with II-Na₃Fe₂(AsO₄)₃ and yurmarinite: synthesis, potassium disorder, crystal chemistry and ionic conductivity

K_3–xNa_1+xM₄(MoO₄)₆ (M = Ni, Mg, Co) and K_3+xLi_1–xMg₄(MoO₄)₆ are isostructural with the sodium-ion conductor II-Na₃Fe₂(AsO₄)₃ and yurmarinite, Na₇(Fe³⁺, Mg, Cu)₄(AsO₄)₆, and have 3D frameworks of MoO₄ tetrahedra and tetramers of MO₆ octahedra with disordered K(Na) in cavities. Electrical conductivity of the triple molybdates (about 10⁻⁶ S cm⁻¹ at 390°C) is more than two orders of magnitude lower com­pared with II-Na₃Fe₂(AsO₄)₃.

Structural and optical characterization of Er-doped CaMoO₄ down-converting phosphors

Structural and optical properties of Er₂O₃-doped CaMoO₄ nanoparticles used as UV detectors are presented.

Crystal structures and phase transitions of imidazolium hypodiphosphates

Imidazolium hypodiphosphates (C₃H₅N₂)(H₃P₂O₆) (I) and (C₃H₅N₂)₂(H₂P₂O₆) (II) are characterized using differential scanning calorimetry, thermogravimetric analysis, single-crystal and powder X-ray diffraction. Structural analysis supported by dielectric spectroscopy of (I) indicates the freezing of motion of imidazolium cations as being the driving force of the phase transitions: orthorhombic HTP (Pnna) → incommensurately modulated RTP → monoclinic LTP (P2₁/n11).

Crystal structures of alpha and beta modifications of Mn as packing of tetrahedral helices extracted from a four-dimensional {3, 3, 5} polytope

Crystal structures of both α- and β-Mn modifications have been presented as packing of tetrahedral helices extracted from four-dimensional {3, 3, 5} polytope construction.

Introduction to Graphene-Based Nanomaterials. From Electronic Structure to Quantum Transport. 2nd edition. By Luis E. F. Foa Torres, Stephan Roche and Jean-Christophe Charlier. Cambridge University Press, 2020. Hardback, 476 pp. Price GBP 74.99. ISBN 978-1-108-47699-7