1H and13C NMR study of complexes of nickel(II) with water and saturated alcohols

Journal of Structural Chemistry -     

Paramagnetic relaxation of radical cations in alkane solutions as measured by time-resolved magnetic field effects

Spin-lattice relaxation times of radical cations were measured by the decay of the time-resolved magnetic field effect in the recombination fluorescence of radical ion pairs in liquid hydrocarbons at high concentrations of solvent holes acceptor. The dependences of spin-lattice relaxation time on the magnetic field strength and solvent viscosity were studied. The results could not be explained in terms of the model of ion-molecular charge transfer involving monomeric or dimeric radical cations. The paramagnetic relaxation observed in a weak magnetic field is attributed to internal reorganizations of aggregates that originate from radical cations at high acceptor concentration.     

硫化物固态电解质Li10GeP2S12与锂金属间界面稳定性的改善研究

通过N-丁基-N-甲基哌啶双（氟磺酰）亚胺盐离子液体和双（氟磺酰）亚胺锂盐修饰了Li|Li₁₀GeP₂S₁₂界面，并研究了界面的改性效果.研究结果表明，在界面处原位生成一层致密的固体电解质界面膜（SEI），具有一定流变性的离子液体可渗透到Li₁₀GeP₂S₁₂晶粒内部；在0.1 mA/cm²的电流密度下，界面改性后的Li|Li₁₀GeP₂S₁₂|Li对称电池可稳定循环1500 h以上，极化电压仅为30 mV.在2.5~3.6 V电压范围内，Li|Li₁₀GeP₂S₁₂|LiFePO₄电池在0.2C倍率下充放电循环的首次放电比容量为148.1 mA·h/g，库仑效率为95.8%，经过30次循环后容量保持率为90.1%.     

Mechanosensitive Membrane Probes

This article assembles pertinent insights behind the concept of planarizable push–pull probes. As a response to the planarization of their polarized ground state, a red shift of their excitation maximum is expected to report on either the disorder, the tension, or the potential of biomembranes. The combination of chromophore planarization and polarization contributes to various, usually more complex processes in nature. Examples include the color change of crabs or lobsters during cooking or the chemistry of vision, particularly color vision. The summary of lessons from nature is followed by an overview of mechanosensitive organic materials. Although often twisted and sometimes also polarized, their change of color under pressure usually originates from changes in their crystal packing. Intriguing exceptions include the planarization of several elegantly twisted phenylethynyl oligomers and polymers. Also mechanosensitive probes in plastics usually respond to stretching by disassembly. True ground‐state planarization in response to molecular recognition is best exemplified with the binding of thoughtfully twisted cationic polythiophenes to single‐ and double‐stranded oligonucleotides. Molecular rotors, en vogue as viscosity sensors in cells, operate by deplanarization of the first excited state. Pertinent recent examples are described, focusing on λ‐ratiometry and intracellular targeting. Complementary to planarization of the ground state with twisted push–pull probes, molecular rotors report on environmental changes with quenching or shifts in emission rather than absorption. The labeling of mechanosensitive channels is discussed as a bioengineering approach to bypass the challenge to create molecular mechanosensitivity and use biological systems instead to sense membrane tension. With planarizable push–pull probes, this challenge is met not with twistome screening, but with “fluorescent flippers,” a new concept to insert large and bright monomers into oligomeric probes to really feel the environment and also shine when twisted out of conjugation.     

New Possibilities of OD ESR: Vacuum Ultraviolet Generation of Radical Ion Pairs

A new version of the optically detected electron spin resonance (OD ESR) technique using vacuum ultraviolet radiation to generate radical ion pairs is discussed. The technique can be used to study the spin-correlated processes of charge recombination in thin films that can be useful in spintronics. Distinctive features of photoionization and high-energy (including X-ray) ionization are discussed. The first results obtained by the technique in the study of charge recombination in polymeric and liquid crystal films are presented. The results of the concurrent observation of the OD ESR and electron cyclotron resonance (ECR) in the low-pressure gas over the sample are outlined. A possible application of ECR in the context of the OD ESR spectroscopy is suggested.     

Phase Field Approach to Multiphase Flow Modeling

We review the phase field (otherwise called diffuse interface) model for fluid flows, where all quantities, such as density and composition, are assumed to vary continuously in space. This approach is the natural extension of van der Waals?? theory of critical phenomena both for one-component, two-phase fluids and for partially miscible liquid mixtures. The equations of motion are derived, assuming a simple expression for the pairwise interaction potential. In particular, we see that a non-equilibrium, reversible body force appears in the Navier-Stokes equation, that is proportional to the gradient of the generalized chemical potential. This, so called Korteweg, force is responsible for the convection that is observed in otherwise quiescent systems during phase change. In addition, in binary mixtures, the diffusive flux is modeled using a Cahn-Hilliard constitutive law with a composition-dependent diffusivity, showing that it reduces to Fick??s law in the dilute limit case. Finally, the results of several numerical simulations are described, modeling, in particular, a) mixing, b) spinodal decomposition, c) nucleation, d) enhanced heat transport, e) liquid-vapor phase separation.