Predicting photoactivity in dithienylethene crystalline solids

This commentary discusses the design of stimuli-responsive materials, specifically, light-responsive dithienylethene-based compounds. Recent progress in predicting photoactivity using a combination of theory and crystal structure landscape experiments is highlighted.

Thinner than a knife's edge: 3D-printed liquid sheet jet technology for solution phase XFEL experiments

In this commentary, we explore the pioneering implementation of 3D-printed thin liquid sheet devices for advanced X-ray scattering and spectroscopy experiments at high-repetition rate XFELs.

Going around the Kok cycle of the water oxidation reaction with femtosecond X-ray crystallography

Photosystem II is the enzyme responsible for generating nearly all the oxygen in the atmosphere. Room-temperature time-resolved crystallography and spectroscopy measurements at X-ray free-electron lasers help to elucidate the sequence of events in the water oxidation reaction of photosystem II leading to the formation of di­oxy­gen from two molecules of water.

Emergence of liquid following laser melting of gold thin films

Diffuse X-ray scattering is used to characterize the time dependence of the liquid phase emerging from femtosecond laser-induced melting of polycrystalline gold thin films using an XFEL. Its structure factor and partial pair distribution function confirm the liquid origin of the diffuse scattering. The liquid fraction increases with a characteristic rise-time of 13 ps.

3D-printed sheet jet for stable megahertz liquid sample delivery at X-ray free-electron lasers

In this study, liquid sheet jet sample injection was demonstrated at the EuXFEL SPB/SFX beamline. A 3D-printed gas-accelerated nozzle design was used to produce sheet jet thicknesses below 100 nm resulting in a significantly more stable scattering signal compared with a conventional cylindrical liquid jet. The radiation-induced explosion was found to not perturb data collection for repetition rates approaching megahertz. These results demonstrate the great potential of sheet jets for high-repetition-rate liquid sample injection and their adoption for both scattering and spectroscopy experiments.

A new route for the syntheses of coordination polymers using magnetic influence: syntheses, crystal structures and fluorescence properties

Five coordination polymers were obtained based on an azo multifunctional aromatic ligand. The movement and collision behaviors of components are greatly affected by the magnetic field assisted method, which could have a subsequent impact on their structures with different space groups.

Micro-structured polymer fixed targets for serial crystallography at synchrotrons and XFELs

The micro-structured polymer chip is a new polymer fixed-target support for serial crystallography experiments at synchrotrons and X-ray free-electron lasers; these micro-structured supports contain a precise array of apertures that allow rapid aperture-alignment-based data-collection strategies. Here, the chip-fabrication process is presented and discussed, as well as an analysis of ideal crystal-loading parameters and data quality.

Development of a scalar-based geometric parameterization approach for the crystal structure landscape of dithienylethene-based crystalline solids

The crystal structure landscape of (Z)-1,2-bis­[2-methyl-5-(pyridin-4-yl)thio­phen-3-yl]-1,2-di­phenyl­ethene (DTE) was determined using a combination of computational and experimental molecular geometries. A novel D–D analysis was developed which provides a rapid, effective and intuitive means of visualizing the crystal landscape and assessing the conformer type present in and photoactivity of the resulting crystalline solids.

Observing femtosecond orbital dynamics in ultrafast Ge melting with time-resolved resonant X-ray scattering

Bonding orbital dynamics in ultrafast melting have been directly observed using femtosecond time-resolved resonant X-ray scattering at the Pohang Accelerator Laboratory X-ray Free-Electron Laser, and smoking-gun evidence on direct linkage between bonding orbitals and lattice stability unifying thermal-to-nonthermal reactions to explicate photo-induced phase transitions is provided.

A phenomenological model of the X-ray pulse statistics of a high-repetition-rate X-ray free-electron laser

A simple, robust and computationally inexpensive method of generating statistical representations of X-ray free-electron laser (XFEL) radiation is presented.

Single-crystal quality data from polycrystalline samples: finding the needle in the haystack

Advances in X-ray hardware and software have revolutionized crystallography: now crystal structures can be routinely solved first, with publication-quality datasets collected second. This same approach now allows multi-grain crystallography to be completed in the laboratory with Cu Kα X-rays.

Kilohertz serial crystallography with the JUNGFRAU detector at a fourth-generation synchrotron source

The first demonstration of 2 kHz time-resolved serial crystallography data acquisition at a fourth-generation synchrotron, using the JUNGFRAU 4M pixel detector.

Structural snapshots of Mycobacterium tuberculosis enolase reveal dual mode of 2PG binding and its implication in enzyme catalysis

Enolase catalyzes the reversible conversion of 2-phosphoglycerate to phosphoenolpyruvate. Structural snapshots of Mycobacterium tuberculosis enolase provide critical insights into the mechanism of conversion of phosphoenolpyruvate to 2-phosphoglycerate.

A transferable quantum mechanical energy model for intermolecular interactions using a single empirical parameter

A new interaction energy model for molecular dimers, CE-1p, accurately calculates intermolecular interactions in molecular crystals. Improved treatment of dispersion and polarization helps it outperform existing models with accuracy comparable to advanced DFT methods with only a single fitted parameter.

A new polymorph of white phospho­rus at ambient conditions

We present δ-P₄, a new polymorph of white phospho­rus. It crystallizes as a sixfold twin with the cell dimensions a = 18.302 (2), b = 18.302 (2), c = 36.441 (3) Å in the space group P2₁2₁2₁ with 29 P₄ tetrahedra in the asymmetric unit. Although their arrangement resembles the structure of α-Mn as proposed for α-P₄, δ-P₄ differs from α-P₄.