The structure of a hexa­kis­(imidazole)­cobalt(II) bis­(benzene-1,3,5-tri­carboxyl­ate) tetra­(imidazole-1-ium) dihydrate compound was determined by single-crystal X-ray diffraction.

We demonstrate two-dimensional (2-D) imaging and resonant inelastic X-ray scattering (RIXS) spectroscopy in the hν 2 “mapping” scheme using a reflection zone plate (RZP) at soft X-rays. Experiments at the PETRA III storage ring (DESY) around the N K α line (392.4 eV) verify that an RZP can be used in the paraxial regime combined with the 1-D line scanning mode for time-efficient full-field imaging of an extended object with an angular size of 2.5 mrad at low aberrations, even for off-design energies, at a spatial resolution of (14–24) μ m. A similar setup collects the RIXS spectra of acetonitrile within (388.6–401.8) eV for a variable incident photon energy between 399 eV and 400 eV, at a potential resolution of (0.3 ± 0.1) eV. RZPs with their precise manufacturability, efficiency, and strong dispersion can serve as advantageous diffractive optical elements in soft X-ray microscopy or “photon-in vs. photon-out” spectroscopy.

This article reports the room-temperature synthesis of ZIF-8 monoliths, systematically varying synthesis parameters while maintaining a constant metal:ligand ratio of 1:7.9. The washing procedure, aging time, centrifugal speed, precursor concentration, solvent type, ammonia concentration, and metal salt were changed to investigate their effect on the water stability of the resulting monolith. The synthesised monoliths were characterised by optical microscopy, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA) and N2 gas adsorption, while the precursor nanocrystallites were analysed by scanning electron microscopy (SEM). Water stability was evaluated by immersing monolithic pieces in Mili-Q water for 24 hrs, followed by UV-Vis spectroscopy to track linker release and inductive coupled plasma optical emission spectroscopy (ICP-OES) to quantify metal ion leaching. The use of Zn(CH3COO)2, along with the washing procedure, are the most important parameters for improving water stability and enhancing the phase purity, textural properties and transparency of the monolith. Other parameters contributing to these characteristics are centrifugal speeds exceeding 4200 rpm, concentrated synthesis, and partial replacement of methanol for aqueous ammonia. Based on this comprehensive analysis, a refined synthesis protocol was formed, yielding a more water-stable ZIF-8 monolith. However, despite its improved stability, the monolith was unable to adsorb rhodamine B from aqueous solutions as the dye’s size far exceeds the pore window of ZIF-8, limiting adsorption to the external surface.

ABSTRACT Nano‐sized hydrogel drug carriers with tailored hydro‐ and lipophilicity are designed and their encapsulation and structure‐forming capabilities investigated in real‐time. These nano‐carriers are built from cellulose and peptide hydrogels in tandem with a nano‐stacked interwoven design and alternating hydro‐ and lipophilicity, thus enabling tuning of the lipophilicity of the carrier mesh for drugs of complementary lipophilicities. This allows for a variety of therapeutic applications, based on the nanoproperties of the hydrogel. Time‐resolved and in situ grazing incidence x‐ray scattering studies confirm the design and hydro‐ and lipophilicities of the fiber‐hydrogel composite and conclude their ability for carrying drugs of complementary properties site specific. This approach allows for a novel way of understanding the functionality of drug carriers using photon‐based approach.

The title compound, (C3H5N2)4[Co(C3H4N2)6](C9H3O6)2·2H2O (1), was synthesized by slow evaporation of mixed ethanolic solutions of CoCl2, benzene-1,3,5-tricarboxylic acid (H3btc) and imidazole (Im) at room temperature. The crystal structure comprises [Co(Im)6]2+ cations, btc3− anions, Im+ cations and water molecules in a 1:2:4:2 ratio. The crystal packing shows alternating layers stacked along the c-axis direction, linked primarily by hydrogen bonds of the types N—H...O (between cations and anions) and O—H...O (between anions and water molecules).

The title compound, (C3H5N2)4[Co(C3H4N2)6](C9H3O6)2·2H2O (1), was synthesized by slow evaporation of mixed ethano-lic solutions of CoCl2, benzene-1,3,5-tri-carb-oxy-lic acid (H3btc) and imidazole (Im) at room temperature. The crystal structure comprises [Co(Im)6]2+ cations, btc3- anions, Im+ cations and water mol-ecules in a 1:2:4:2 ratio. The crystal packing shows alternating layers stacked along the c-axis direction, linked primarily by hydrogen bonds of the types N-H⋯O (between cations and anions) and O-H⋯O (between anions and water mol-ecules).

The structure of the title salt, 3C4H7N2 +·C9H5O6 -·C9H4O6 2-, 1, consists of three 2-methyl-imidazolium cations and both a single and a doubly deprotonated form of trimesic acid as anions. A detailed analysis of the bond lengths and angles reveals both differences and similarities between compound 1 and the previously reported 2-methyl-1H-imidazol-3-ium 3,5-di-carb-oxy-benzoate structure [Baletska et al. (2023). Acta Cryst. E79, 1088-109], as well as the neutral counterpart of the ions. Examination of the crystal packing shows the formation of infinite chains by the anions, which, along with the cations, form zigzag planes parallel to the ab plane. The packing inter-actions are primarily driven by π-π inter-actions and hydrogen bonding between anions.

The title compound, [CoII(C3H4N2)6]3(C9H3O6)2 (1), was synthesized from cobalt chloride(II), benzene-1,3,5-tricarboxylic acid (H3btc) and imidazole (Im) in an ethanol/DMF mixture via slow evaporation at room temperature. This compound consists of three hexakis(imidazole)cobalt(II) cations and two trimesate anions. Examination of the crystal packing shows the formation of one-dimensional stacks of ions propagating along the c axis. The packing interactions are primarily driven by N—H...O hydrogen bonding between anions and cations.

A novel concept of nano-scaled interwoven templates for drug delivery with alternating hydro- and lipophilicity properties is introduced. They are built from cellulose and peptide hydrogel in tandem, and characterized by a nano-stacked interwoven design, thus enabling for tuning the lipophilicity in the mesh nano-domains in which drug candidates of complementary lipophilicities can be embedded. This allows for low-dose-controlled consumption and therapeutic applications. Time-resolved and in-situ grazing incidence X-ray scattering studies confirm the design of the therapeutic nano-paper and create conditions suitable for the drug storage of complementary properties. The molecular design has the potential of a locally controlled, site-specific drug release on a beyond-nanomolar scale. Generalized, the design may contribute to facile developments of personalized medicine.

The structure of the title salt, 3C4H7N2+·C9H3O63− (1), is reported. The compound is formed with three 2-methylimidazolium cations and a fully deprotonated trimesic acid. The structure is disordered over two orientations, which were refined using a split model (90.99: 9.01occupancy ratio). Analysis of bond distances and angles reveals the differences and similarities between compound 1 and the previously published 2-methyl-1H-imidazol-3-ium 3,5-dicarboxybenzoate structure [Baletska et al., (2023). Acta Cryst. E79, 1088–1092] and tris(2-methyl-1H- imidazol-3-ium) 5-carboxybenzene-1,3-dicarboxylate 3,5-dicarboxybenzoate [Asprilla-Herrera et al. (2025). Acta Cryst. E81, 303–309], as well as the neutral counterparts of the ions [Tothadi et al. (2020). ACS Appl. Mater. Interfaces, 12, 15588–15594; Hachuła et al. (2010). J. Chem. Crystallogr. 40, 201–206]. The crystal packing analysis reveals the formation of hydrogen-bonded two-dimensional networks perpendicular to the [111] vector, where neighbouring planes interact via extensive π–π stacking.

Resonant Inelastic X-ray Scattering (RIXS) is an ideal X-ray spectroscopy method to push the combination of energy and time resolutions to the Fourier transform ultimate limit, because it is unaffected by the core-hole lifetime energy broadening. And in pump-probe experiments the interaction time is made very short by the same core-hole lifetime. RIXS is very photon hungry so it takes great advantage from high repetition rate pulsed X-ray sources like the European XFEL. The hRIXS instrument is designed for RIXS experiments in the soft X-ray range with energy resolution approaching the Fourier and the Heisenberg limits. It is based on a spherical grating with variable line spacing (VLS) and a position-sensitive 2D detector. Initially, two gratings are installed to adequately cover the whole photon energy range. With optimized spot size on the sample and small pixel detector the energy resolution can be better than 40 meV at any photon energy below 1000 eV. At the SCS instrument of the European XFEL the spectrometer can be easily positioned thanks to air-pads on a high-quality floor, allowing the scattering angle to be continuously adjusted over the 65-145 deg range. It can be coupled to two different sample interaction chamber, one for liquid jets and one for solids, each equipped at the state-of-the-art and compatible for optical laser pumping in collinear geometry. The measured performances, in terms of energy resolution and count rate on the detector, closely match design expectations. hRIXS is open to public users since the summer of 2022.

The structure of the title salt, 3C4H7N2+·C9H5O6−·C9H4O62−, 1, consists of three 2-methyl-imidazolium cations and both a single and a doubly deprotonated form of trimesic acid as anions. A detailed analysis of the bond lengths and angles reveals both differences and similarities between compound 1 and the previously reported 2-methyl-1H-imidazol-3-ium 3,5-dicarboxybenzoate structure [Baletska et al. (2023). Acta Cryst. E79, 1088–109], as well as the neutral counterpart of the ions. Examination of the crystal packing shows the formation of infinite chains by the anions, which, along with the cations, form zigzag planes parallel to the ab plane. The packing interactions are primarily driven by π–π interactions and hydrogen bonding between anions.

Despite significant advancements in materials design for renewable energy devices, the fundamental understanding of the underlying processes in many materials remains limited, particularly in complex, inhomogeneous systems and interfaces. In such cases, in situ studies with high spatial and energy resolution are essential for uncovering new insights into excitation, dissipation, and conversion processes. Recent progress in in situ atomic scale methods has greatly enhanced the understanding of energy materials. Here, key advances are reviewed, including in situ, environmental and ultra-fast transmission electron microscopy, scanning probe techniques, single-photon-resolved infrared spectroscopy, velocity-resolved molecular kinetics, and in situ grazing-incidence X-ray spectroscopy. These techniques enable the study of energy conversion with spatial resolution from nanometers down to individual atoms, energy resolution down to meV, and single-quantum detection. Especially they enable access to processes that involve multiple degrees of freedom, strong coupling, or spatial inhomogeneities. They have driven a qualitative leap in the fundamental understanding of energy conversion processes, opening new avenues for improving existing materials and designing novel clean and efficient energy materials in photovoltaics, friction, and surface chemistry and (photo-)electrochemistry.

Strong electronic correlation can lead to insulating behavior and to the opening of large optical gaps, even in materials with partly filled valence shells. Although the non-equilibrium optical response encodes both local (quasi atomic) and collective (long range) responses, optical spectroscopy is usually more sensitive to the latter. Resonant x-ray techniques are better suited to investigate the quasi-atomic properties of correlated solids. Using time-resolved resonant inelastic x-ray scattering (RIXS), here we study the ultrafast non-equilibrium processes in NiO following photo-excitation by ultraviolet photons with energy exceeding the optical gap. We observe the creation of charge-transfer excitons that decay with a time constant of about 2 ps, while itinerant photo-doping persists for tens of picoseconds. Following our discovery, which establishes time-resolved high-resolution RIXS as a powerful tool for the study of transient phenomena in condensed matter, the possible presence of charge-transfer excitons will need to be considered when interpreting optical pump-probe experiments on correlated quantum materials.

Laser-driven dynamics in polyatomic molecules poses a complex many-body problem. Understanding intense light-matter interaction is crucial for steering intramolecular quantum dynamical processes. Here, we record time-resolved x-ray diffraction images of C60 molecules during and after their interaction with intense near-infrared fields, giving direct access to structural changes of the molecules and their fragmentation in real time. Tuning the intensity of the excitation pulses, we uncover a transition from a weak-field regime of excited but stable molecules to a high-field regime dominated by Coulomb explosion. In the transition region, the molecules expand by up to 50% of their initial size within just 140 fs, with major fragmentation only setting in afterward. This work demonstrates that x-ray diffractive imaging is capable of retrieving time-resolved structural information of large molecules reshaped by intense laser fields. Laser-driven fragmentation is a first step toward observing molecular processes modified by laser fields of increasing intensity.

Despite numerous publications reporting the instability of ZIF-8 in water, it is still used for water purification, including the adsorption of molecules significantly larger than the pore window. This work involves the synthesis, characterisation and application of ZIF-8 monoliths, including those doped with Ni, Co and Cu at levels of 4%, 8% and 12%, for rhodamine B adsorption in water. Characterisation techniques include optical microscopy, PXRD, FTIR, SEM-EDX, TGA-FTIR and N2 adsorption. The results reveal mm-cm sized monoliths with an identical crystalline structure and morphology, but different properties depending on the doping metal and level. Except for 4% of Co-doped ZIF-8, doping generally narrows the pore size distribution to micropores (maximum between 10.9 and 11.6 & Aring;), whereas the undoped monolith shows a combination of micropores and mesopores (10.2-38 & Aring;). Doping with more than 4% Co2+ or Cu2+ results in higher BET surface areas (up to 1180 and 1100 m2 g-1, respectively) compared to the undoped monolith (960 m2 g-1). However, when immersed in a 10 mg L-1 rhodamine B solution, all monoliths exhibit both slower adsorption kinetics and reduced capacities (0.61 and 1.82 mg g-1) compared to the reported nano-/microsized particles. Desorption of rhodamine B occurred between 9 and 24 h, attributed to up to 20% degradation of the monolith. Immersion in Milli-Q water for five days led to a white residue on the surface, with FTIR indicating a new phase. These results suggest that ZIF-8 and its variants are unsuitable for adsorbing large molecules in water but are suitable for small molecules like gases.

The structure of a tris­[hexa­kis­(imidazole)­cobalt(II)] bis­(benzene-1,3,5-tri­carboxyl­ate) compound was determined by single-crystal X-ray diffraction.