Experimental and theoretical insights into the structure and molecular dynamics of 2,3,3',4'-tetramethoxy--stilbene - a chemopreventive agent.

The methoxy analogue of a -stilbene compound - 2,3,3',4'-tetramethoxy--stilbene - was selected to characterize its crystallographic structure, intermolecular interactions and molecular dynamics. The sample was studied using single-crystal X-ray diffraction (XRD), infrared spectroscopy (FT-IR), liquid and solid-state H and C nuclear magnetic resonance (NMR) and quasielastic neutron scattering (QENS). The compound crystallized in the orthorhombic space group.

The magnetic properties of MAl(OH)SO·3HO with M = Co, Ni, and Cu determined by a combined experimental and computational approach.

The magnetic properties of the nickelalumite-type layered double hydroxides (LDH), MAl(OH)(SO)·3HO (MAl-LDH) with M = Co ( = 3/2), Ni ( = 1), or Cu ( = 1/2) were determined by a combined experimental and computational approach. They represent three new inorganic, low-dimensional magnetic systems with a defect-free, structurally ordered magnetic lattice. They exhibit no sign of magnetic ordering down to 2 K in contrast to conventional hydrotalcite LDH.

Fast Room-Temperature Mg Conductivity in Mg(BH)·1.6NH-AlO Nanocomposites.

Design of new functional materials with fast Mg-ion mobility is crucial for the development of competitive solid-state magnesium batteries. Herein, we present new nanocomposites, Mg(BH)·1.6NH-AlO, reaching a high magnesium conductivity of σ(Mg) = 2.

Transport Mechanism of Acetamide in Deep Eutectic Solvents.

Over the last couple of decades, deep eutectic solvents (DESs) have emerged as novel alternatives to ionic liquids that are extensively used in the synthesis of innovative materials, metal processing, catalysis, etc. However, their usage is limited, primarily because of their large viscosity and poor conductivity. Therefore, an understanding of the molecular origin of these transport properties is essential to improve their industrial applicability.

Linking Structure to Dynamics in Protic Ionic Liquids: A Neutron Scattering Study of Correlated and Single-Particle Motions.

Coupling between dynamical heterogeneity of ionic liquids and their structural periodicity on different length-scales can be directly probed by quasielastic neutron scattering with polarization analysis. The technique provides the tools to investigate single-particle and cooperative ion motions separately and, thus, dynamics of ion associations affecting the net charge transport can be experimentally explored. The focus of this study is the structure-dynamic relationship in the protic ionic liquid, triethylammonium triflate, characterized by strong hydrogen bonds between cations and anions.

Dynamics of the Coordination Complexes in a Solid-State Mg Electrolyte.

Coordination complexes of magnesium borohydride show promising properties as solid electrolytes for magnesium ion batteries and warrant a thorough microscopic description of factors governing their mobility properties. Here, the dynamics of Mg(BH)-diglyme on the atomic level are investigated by means of quasielastic neutron scattering supported by density functional theory calculations and IR and NMR spectroscopy. Employing deuterium labeling, we can unambiguously separate all the hydrogen-containing electrolyte components, which facilitate Mg transport, and provide a detailed analytical description of their motions on the picosecond time scale.

Low-Frequency Dynamics of BSA Complementarily Studied by Raman and Inelastic Neutron Spectroscopy.

The present study focuses on protein motions on the picosecond time scale, generally characterized by the overlapping of vibrational and relaxational dynamics in disordered molecular systems. Recently, it has been demonstrated that a dry protein, bovine serum albumin (BSA), shows a glass-like transition in the temperature range between 240 and 260 K. Here, we present the results of combined low-frequency Raman and inelastic neutron scattering studies of dry BSA under conditions similar to those of this glass-like transition.

Confinement Effects for Lithium Borohydride: Comparing Silica and Carbon Scaffolds.

LiBH is a promising material for hydrogen storage and as a solid-state electrolyte for Li ion batteries. Confining LiBH in porous scaffolds improves its hydrogen desorption kinetics, reversibility, and Li conductivity, but little is known about the influence of the chemical nature of the scaffold. Here, quasielastic neutron scattering and calorimetric measurements were used to study support effects for LiBH confined in nanoporous silica and carbon scaffolds.

Dynamic Heterogeneity and Flexibility of the Alkyl Chain in Pyridinium-Based Ionic Liquids.

Changing the number of carbon atoms in the substituents of ionic liquids (ILs) is a way to shift the balance between Coulomb and van der Waals forces and, thus, to tune physicochemical properties. Here we address this topic on the microscopic level by employing quasielastic neutron scattering (QENS) and provide information about the stochastic ionic motions in the N-alkylpyridinium based ILs in a relatively expanded time range, from short time (subpicosecond) particle rattling to long time diffusive regime (hundreds of picoseconds). We have systematically investigated the effect of the alkyl chain length on the picosecond dynamics by employing partial deuteration of the samples and varying the number of carbon atoms in the alkyl substituent.

Phononic Structure Engineering: the Realization of Einstein Rattling in Calcium Cobaltate for the Suppression of Thermal Conductivity.

Phonons in condensed matter materials transmit energy through atomic lattices as coherent vibrational waves. Like electronic and photonic properties, an improved understanding of phononic properties is essential for the development of functional materials, including thermoelectric materials. Recently, an Einstein rattling mode was found in thermoelectric material Na0.

Proton Diffusivity in the Protic Ionic Liquid Triethylammonium Triflate Probed by Quasielastic Neutron Scattering.

Quasielastic neutron scattering (QENS) in combination with deuterium labeling allows for studying protonated "highlighted" species and extracting detailed information about tangled stochastic processes. This approach has been applied to examine proton dynamics in the protic ionic liquid, triethylammonium triflate. The temperature range covered during the experiments (2-440 K) included two melting transitions correspondingly reflected in the global and localized dynamics of the cation.

Collective ion diffusion and localized single particle dynamics in pyridinium-based ionic liquids.

Quasielastic neutron scattering with polarized neutrons allows for an experimental separation of single-particle and collective processes, as contained in the incoherent and coherent scattering contributions. This technique was used to investigate the dynamical processes in the pyridinium-based ionic liquid 1-butylpyridinium bis(trifluoromethylsulfonyl)-imide. We observed two diffusion processes with different time scales.

Picosecond dynamics in haemoglobin from different species: a quasielastic neutron scattering study.

Background: Dynamics in haemoglobin from platypus (Ornithorhynchus anatinus), chicken (Gallus gallus domesticus) and saltwater crocodile (Crocodylus porosus) were measured to investigate response of conformational motions on the picosecond time scale to naturally occurring variations in the amino acid sequence of structurally identical proteins.

Methods: Protein dynamics was measured using incoherent quasielastic neutron scattering. The quasielastic broadening was interpreted first with a simple single Lorentzian approach and then by using the Kneller-Volino Brownian dynamics model.

Does a dry protein undergo a glass transition?

Bovine serum albumin (BSA) with extremely low hydration level 0.04, which is usually defined as dry, has been investigated in the temperature range between 200 and 340 K by incoherent inelastic neutron scattering using the neutron time-of-flight spectrometer FOCUS (PSI, Switzerland). Anomalous temperature behavior has been revealed for relaxational and low-frequency vibrational dynamics of BSA in the vicinity of 250 K.

Cation dynamics in the pyridinium based ionic liquid 1-N-butylpyridinium bis((trifluoromethyl)sulfonyl) as seen by quasielastic neutron scattering.

Quasielastic neutron scattering (QENS) has been used to study the cation dynamics in the pyridinium based ionic liquid (IL) 1-N-butylpyridinium bis((trifluoromethyl)sulfonyl)imide (BuPy-Tf(2)N). This IL allows for a detailed investigation of the dynamics of the cations only, due to the huge incoherent scattering cross section of the cation (σ(inc)(cation) >> σ(inc)(anion)). The measured spectra can be decomposed into two Lorentzian lines, indicative of two distinct dynamic processes.

Rotational motion in LiBH4/LiI solid solutions.

We investigated the localized rotational diffusion of the (BH(4))(-) anions in LiBH(4)/LiI solid solutions by means of quasielastic and inelastic neutron scattering. The (BH(4))(-) motions are thermally activated and characterized by activation energies in the order of 40 meV. Typical dwell times between jumps are in the picosecond range at temperatures of about 200 K.

Cytoplasmic water and hydration layer dynamics in human red blood cells.

The dynamics of water in human red blood cells was measured with quasielastic incoherent neutron scattering in the temperature range between 290 and 320 K. Neutron spectrometers with time resolutions of 40, 13, and 7 ps were combined to cover time scales of bulk water dynamics to reduced mobility interfacial water motions. A major fraction of approximately 90% of cell water is characterized by a translational diffusion coefficient similar to bulk water.