How Amino Acids Intercalate in CaFe Layered Double Hydroxides: A Combined RIXS and NEXAFS Study.

Two-dimensional layered double hydroxides (LDHs) are ideal candidates for a large number of (bio)catalytic applications due to their flexible composition and easy to tailor properties. Functionality can be achieved by intercalation of amino acids (as the basic units of peptides and proteins). To gain insight on the functionality, we apply resonant inelastic soft x-ray scattering and near edge x-ray absorption fine structure spectroscopy to CaFe LDH in its pristine form as well as intercalated with the amino acids proline and cysteine to probe the electronic structure and its changes upon intercalation.

Cooperative Dynamics and Hydration of Aqueous D-Mannitol and -Inositol.

The cooperative dynamics and hydration of D-mannitol and yo-inositol in aqueous solution at 25 °C were investigated by broad-band dielectric relaxation spectroscopy (DRS) for solute concentrations < 0.9M. The recorded spectra, covering the frequency range 0.

Ion Association and Hydration of Some Heavy-Metal Nitrate Salts in Aqueous Solution.

Aqueous solutions of four heavy-metal nitrate salts (AgNO, TlNO, Cd(NO) and Pb(NO)) have been studied at 25 °C using broadband dielectric relaxation spectroscopy (DRS) at frequencies 0.27 ≤ ν/GHz ≤ 115 over the approximate concentration range 0.2 ≲ /mol L ≲ 2.

Cognitive performance in adults with post-COVID syndrome: Results from a German case-control study.

Numerous studies on post-COVID syndrome (PCS) describe persisting symptoms of cognitive impairment. Previous studies, however, often investigated small samples or did not assess covariates possibly linked to cognitive performance. We aimed to describe 1) global and domain-specific cognitive performance in adults with PCS, controls with previous SARS-CoV-2 infection and healthy controls, 2) associations of sociodemographics, depressive symptoms, anxiety, fatigue, somatic symptoms and stress with cognitive performance and subjective cognitive decline (SCD), using data of the LIFE-Long-COVID-Study from Leipzig, Germany.

Cation-Binding of Glutamate in Aqueous Solution.

Interactions of the cations Li, Na, Mg, and Ca with L-glutamate (Glu) in aqueous solution were studied at room temperature with dielectric relaxation spectroscopy in the gigahertz region. Spectra of ∼0.4 M NaGlu with added LiCl, NaCl, MgCl, or CaCl ((MCl) ≤ 1.

Pixelated High- Metasurfaces for in Situ Biospectroscopy and Artificial Intelligence-Enabled Classification of Lipid Membrane Photoswitching Dynamics.

Nanophotonic devices excel at confining light into intense hot spots of electromagnetic near fields, creating exceptional opportunities for light-matter coupling and surface-enhanced sensing. Recently, all-dielectric metasurfaces with ultrasharp resonances enabled by photonic bound states in the continuum (BICs) have unlocked additional functionalities for surface-enhanced biospectroscopy by precisely targeting and reading out the molecular absorption signatures of diverse molecular systems. However, BIC-driven molecular spectroscopy has so far focused on end point measurements in dry conditions, neglecting the crucial interaction dynamics of biological systems.

Recent advances in the use of Trichoderma-containing multicomponent microbial inoculants for pathogen control and plant growth promotion.

Chemical pesticides and fertilizers are used in agricultural production worldwide to prevent damage from plant pathogenic microorganisms, insects, and nematodes, to minimize crop losses and to preserve crop quality. However, the use of chemical pesticides and fertilizers can severely pollute soil, water, and air, posing risks to the environment and human health. Consequently, developing new, alternative, environment-friendly microbial soil treatment interventions for plant protection and crop yield increase has become indispensable.

What is behind a gas stream scrubbing liquid? Monoethanolamine/water mixtures as seen by dielectric relaxation spectroscopy.

High-quality dielectric data for monoethanolamine (MEA)/water mixtures covering the entire miscibility range are presented. For MEA concentrations ≥ 1 M the obtained complex permittivity spectra, covering the frequency range from 0.05 to 89 GHz, are best described by a sum of four Debye relaxations.

The Role of the Lowest Excited Triplet State in Defining the Rate of Photoaquation of Hexacyanometalates.

Photosolvation is a type of ligand substitution reaction started by irradiation of a solution with light, triggering the replacement of a ligand with a molecule from the solvent. The excited state is created through many possible pathways. For the class of hexacyanides of groups 8 and 9 of the periodic table, irradiation in the ligand field band is followed by intersystem crossing to the lowest excited triplet state, which we propose to mediate the photoaquation reaction in this class of complexes.

In-depth study of binary ethanol-triacetin mixtures in relation to their excellent solubilization power.

A significant synergistic effect is observed when solubilizing curcumin or tetrahydrocurcumin in binary mixtures of ethanol and triacetin. The present work deals with a detailed investigation of the solvent system by means of COSMO-RS-based calculations, dynamic light scattering, small-and-wide-angle X-ray scattering, and dielectric relaxation spectroscopy. Theoretical calculations lead to the conclusion that the enhanced solubility is not primarily the result of an interaction optimum between individual surface charge densities.

Typical at glance but interesting when analyzed in detail: A story of Tris hydration.

This paper provides results of dielectric relaxation (DR) spectroscopy of aqueous solutions of tris(hydroxymethyl)aminomethane (Tris) covering frequencies of 0.05 ≤ ν/GHz ≤89. The DR spectra can be well fit by a sum of Cole-Cole relaxation, assigned to the solute, and 2 Debye modes already observed for neat water.

Why Does Ethaline Apparently Behave as an Ideal Binary Mixture?

Phase diagram mixtures of the salt choline chloride (ChCl) with ethylene glycol (EG) surprisingly seem to behave as ideal binary nonelectrolyte mixtures [Agieienko, V.; Buchner, R. 2022, 24, 5265].

Metal-water covalency in the photo-aquated ferrocyanide complex as seen by multi-edge picosecond X-ray absorption.

In this work, we investigate the photo-aquation reaction of the ferrocyanide anion with multi-edge picosecond soft X-ray spectroscopy. Combining the information of the iron L-edge with nitrogen and oxygen K-edges, we carry out a complete characterization of the bonding channels in the [Fe(CN)(HO)] photo-product. We observe clear spectral signatures of covalent bonding between water and the metal, reflecting the mixing of the Fe d orbital with the 3a and 4a orbitals of HO.

Photo-induced ligand substitution of Cr(CO) in 1-pentanol probed by time resolved X-ray absorption spectroscopy.

Cr(CO) was investigated by X-ray absorption spectroscopy. The spectral signature at the metal edge provides information about the back-bonding of the metal in this class of complexes. Among the processes it participates in is ligand substitution in which a carbonyl ligand is ejected through excitation to a metal to ligand charge transfer (MLCT) band.

Correction: Is ethaline a deep eutectic solvent?

Correction for 'Is ethaline a deep eutectic solvent?' by Vira Agieienko , , 2022, , 5265-5268, DOI: https://doi.org/10.1039/D2CP00104G.

Fundamental electronic changes upon intersystem crossing in large aromatic photosensitizers: free base 5,10,15,20-tetrakis(4-carboxylatophenyl)porphyrin.

Free base 5,10,15,20-tetrakis(4-carboxylatophenyl)porphyrin stands for the class of powerful porphyrin photosensitizers for singlet oxygen generation and light-harvesting. The atomic level selectivity of dynamic UV pump - N K-edge probe X-ray absorption spectroscopy in combination with time-dependent density functional theory (TD-DFT) gives direct access to the crucial excited molecular states within the unusual relaxation pathway. The efficient intersystem crossing, that is El-Sayed forbidden and not facilitated by a heavy atom is confirmed to be the result of the long singlet excited state lifetime (Q 4.

Targeting Individual Tautomers in Equilibrium by Resonant Inelastic X-ray Scattering.

Tautomerism is one of the most important forms of isomerism, owing to the facile interconversion between species and the large differences in chemical properties introduced by the proton transfer connecting the tautomers. Spectroscopic techniques are often used for the characterization of tautomers. In this context, separating the overlapping spectral response of coexisting tautomers is a long-standing challenge in chemistry.

Is ethaline a deep eutectic solvent?

With the present contribution we clarify the phase behaviour of choline chloride (ChCl) + ethylene glycol (EG) mixtures for ChCl mole fractions () less than 0.333 and temperatures below 323 K by providing melting points obtained by differential scanning calorimetry for samples containing <300 ppm of water. We show that ethaline, the ChCl : EG mixture of molar ratio 1 : 2 that is usually believed to be the composition of the eutectic point, actually lies in the ChCl-saturated region of the {ChCl + EG} phase diagram.

Dipolar Interactions and Protein Hydration in Highly Concentrated Antibody Formulations.

Molecular interaction mechanisms in high-concentrated protein systems are of fundamental importance for the rational development of biopharmaceuticals such as monoclonal antibody (mAb) formulations. In such high-concentrated protein systems, the intermolecular distances between mAb molecules are reduced to the size of the protein diameter (approx. 10 nm).

Ionic effects on supramolecular hosts: solvation and counter-ion binding in polar media.

For the progress of synthetic supramolecular chemistry in aqueous solution the design of host molecules soluble in this medium is essential. A possible route is the introduction of ionic residues, with the additional advantage that also electrostatic interactions can be used to form supramolecular architectures. In this work we study the effect of different ionic substituents on a resorcin[4]arene host on solvation and counterion binding in water and dimethyl sulfoxide (DMSO).

Hydration and counterion binding of aqueous acetylcholine chloride and carbamoylcholine chloride.

The hydration and Cl ion binding of the neurotransmitter acetylcholine (ACh) and its synthetic analogue, carbamoylcholine (CCh), were studied by combining dilute-solution conductivity measurements with dielectric relaxation spectroscopy and statistical mechanics calculations at 1D-RISM and 3D-RISM level. Chloride ion binding was found to be weak but not negligible. From the ∼30 water molecules coordinating ACh and CCh only ∼1/3 is affected in its rotational dynamics by the cation, with the majority - situated close to the hydrophobic moieties - only retarded by a factor of ∼2.

The porphyrin center as a regulator for metal-ligand covalency and π hybridization in the entire molecule.

The central moiety of porphyrins is shown to control the charge state of the inner complex and links it by covalent interaction to the peripheral substituents. This link, which enables the versatile functions of porphyrins, is not picked up in the established, reduced four orbital picture [Gouterman, , 1961, , 138]. X-ray absorption spectroscopy at the N K-edge with density functional theory approaches gives access to the full electronic structure, in particular the π* manifold beyond the Gouterman orbitals.

Single-Step Flame Aerosol Synthesis of Active and Stable Nanocatalysts for the Dry Reforming of Methane.

We introduce a flame-based aerosol process for producing supported non-noble metal nanocatalysts from inexpensive aqueous metal salt solutions, using catalysts for the dry reforming of methane (DRM) as a prototype. A flame-synthesized nickel-doped magnesia (MgO) nanocatalyst (NiMgO-F) was fully physicochemically characterized and tested in a flow reactor system, where it showed stable DRM activity from 500 to 800 °C. A kinetic study was conducted, and apparent activation energies were extracted for the temperature range of 500-650 °C.

How Hydrogen Bonding Amplifies Isomeric Differences in Pyridones toward Strong Changes in Acidity and Tautomerism.

Steric hindrance of hydration and hydrogen bond enhancement by localized charges have been identified as key factors for the massive chemical differences between the hydroxypyridine/pyridone isomers in aqueous solution. While all isomers occur mainly in the hydroxypyridine form in the gas phase, they differ by more than 3 orders of magnitude both in their acidity and tautomeric equilibrium constants upon hydration. By monitoring the electronic and solvation structures as a function of the protonation state and the O substitution position on the pyridine ring, the amplification of the isomeric differences in aqueous solution has been investigated.