The effects of electrostatic correlations on the ionic current rectification in conical nanopores

Ion‐ion electrostatic correlations are recognized to play a significant role in the presence of concentrated multivalent electrolytes. To account for their impact on ionic current rectification phenomenon in conical nanopores, we use the modified continuum Poisson‐Nernst‐Planck (PNP) equations by Bazant et al. Coupled with the Stokes equations, the effects of the EOF are also included. We thoroughly investigate the dependence of the ionic current rectification ratios as a function of the double layer thickness and the electrostatic correlation length. By considering the electrostatic correlations, the modified PNP model successfully captures the ionic current rectification reversal in nanopores filled with lanthanum chloride LaCl₃. This finding qualitatively agrees with the experimental observations that cannot be explained by the standard PNP model, suggesting that ion‐ion electrostatic correlations are responsible for this reversal behavior. The modified PNP model not only can be used to explain the experiments, but also go beyond to provide a design tool for nanopore applications involving multivalent electrolytes.     

Experimental determination and correlation of bosentan solubility in (PEG 200 + water) mixtures at T= (293.15–313.15) K

The solubility of bosentan (BST) in the aqueous mixtures of polyethylene glycol 200 (PEG 200) at the temperature range, T = (293.15–313.15) K, has been studied using a shake-flask method. The experimental solubility data were correlated with Jouyban–Acree, Jouyban-Acree-van’t Hoff, modified Wilson and Yalkowsky models. Deviations of the calculated solubility from experimental one were determined by percent average relative deviations and relative deviations. In addition, to represent the thermodynamic behaviour of BST in PEG 200 solutions, the apparent thermodynamic functions, Gibbs energy, enthalpy and entropy of dissolution were obtained by using the van’t Hoff and Gibbs equations.     

Green synthesis of ZnO nanoparticles in a room-temperature ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide

Nanoparticles of ZnO with the wurtzite structure have been successfully synthesized via a microwave through the decomposition of zinc acetate dihydrate in an ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, as a solvent. Fundamental characterizations including X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were conducted for the ZnO nanostructures.To explore the growth mechanism, the samples have been prepared in different irradiation time and also cetyltrimethylammonium bromide (CTAB) has been used as the capping reagent.     

Preparation and electromagnetic wave absorption properties of polymer nanocomposites based on new functionalized graphene oxide iron pentacarbonyl and ionic liquid

Research on Chemical Intermediates - This paper presents the preparation of a new epoxy nanocomposite of functionalized graphene oxide (FGO) and iron pentacarbonyl [Fe(CO)5] (IPC) as...     

An efficient and rapid Mn(III) complex catalyzed synthesis of polyhydropyridine derivatives via Hantzsch 4 component condensation

A facile and an efficient one-pot synthesis of polyhydroquinoline derivatives in high yields using N,N′-bis (benzoylacetone) ethylenediamine manganese (III) chloride as an environmentally friendly mild Lewis acid catalyst with high catalytic activity and reusability via the Hantzsch reaction in short reaction time was reported. The reaction proceeded to completion within 5–25 min in 90–97% yield. All of the obtained compounds were obtained in high purity without any use of more purification and characterized by physical and spectroscopic data.     

Design and exploration of caffeine-based Brönsted acidic ionic liquid (CaffBAIL) for the synthesis of DHPMs,xanthenediones, and acridinediones

A novel caffeine-based acidic ionic liquid was synthesized, characterized, and utilized as an efficient and green catalyst for synthesizing DHPMs, xanthenediones, and acridinediones under solvent-free conditions. The prepared IL showed notable catalytic activity in organic reactions under solvent-free conditions with good reusability of four runs. The advantage of the present protocol is underlined by the originality of the prepared ionic liquid, absence of toxic solvents, high yields of products, and short reaction times.

     

Noble Metal Corrosion: Halogen Bonded Iodocarbenium Iodides Dissolve Elemental Gold—Direct Access to Gold–Carbene Complexes

A common method to dissolve elemental gold involves the combination of an oxidant with a Lewis base that coordinates to the gold surface, thus lowering the metal's redox potential. Herein we report the usage of organic iodide salts, which provide both oxidative power and a coordinating ligand, to dissolve gold under formation of organo-gold complexes. The obtained products were identified as Au^III complexes, all featuring Au−C bonds, as shown by X-ray single-crystal analysis, and can be isolated in good yields. Additionally, our method provides direct access to N-heterocyclic carbene (NHC-type) complexes and avoids costly organometallic precursors. The investigated complexes show dynamic behavior in acetonitrile and in the case of the NHC(-type) complexes, the involved species could be identified as a monocarbene [AuI₃(carbene)] and biscarbene complex [AuI₂(carbene)₂]⁺.     

Molecular dynamics simulations of the structure and transport properties of tetra-butylphosphonium amino acid ionic liquids

Systematic molecular dynamics simulations are used to study the structure, dynamics and transport properties of the ionic liquids composed of the tetra-butylphosphonium ([TBP](+), or [P(C(4)H(9))(4)](+)) cation with six amino acid ([AA](-)) anions. The structural features of these ionic liquids were characterized by calculating the partial site-site radial distribution functions, g(r), and computing the dihedral angle distribution of n-butyl side chains in the [TBP](+) cations. The dynamics of the ionic liquids are described by studying the velocity autocorrelation function (VACF) and the mean-square displacement (MSD) for the centers of mass of the ions at different temperatures. The ionic diffusion coefficients and the electrical conductivities were evaluated from both the Einstein and Green-Kubo methods. The cross-correlation terms in the electric-current autocorrelation functions, which are an indication of the ion pair correlations, are investigated. The cationic transference numbers were also estimated to study the contributions of the anions and cations to the transport of charge in these ionic liquids. We determined the role of the amino acid anion structures on the dynamical behavior and the transport coefficients of this family of ionic liquids. In general, the MSD and self-diffusion coefficients of the relatively heavier non-planar [TBP](+) cations are smaller than those of the lighter amino acid anions. Introducing polar functional groups (acid or amide) in the side chain of [AA](-) decreases the diffusion coefficient and electrical conductivity of AAILs. The major factors for determining the magnitude of the transport coefficients are the chemical functionality and the length of the alkyl side chain of the [AA](-) anion of these [TBP][AA] ionic liquids.     

Computation of some thermodynamics, transport, structural properties, and new equation of state for fluid neon using a new intermolecular potential from molecular dynamics simulation

A new pair potential energy function of neon has been determined via the inversion of reduced viscosity collision integrals at zero pressure and fitted to obtain an analytical potential form. The pair potential reproduces the second virial coefficient, viscosity, thermal conductivity, and self-diffusion coefficient of neon in a good accordance with experimental data over wide ranges of temperature and density. We have also performed molecular dynamics simulation to obtain some thermodynamics, transport, and structural properties of fluid neon at different temperatures and densities using our calculated pair potential supplemented by quantum corrections following the Feynman–Hibbs approach. The significance of this work is that the three-body expression of Wang and Sadus (J Chem Phys 125:144509–1, 2006) can be used to improve the prediction of the pressures of neon without requiring an expensive three-body calculation. The molecular dynamics simulation of neon has been also used to determine a new equation of state for neon. Our results are in a good agreement with experiment and literature values.     

Computation of some thermodynamic properties of helium–neon and helium–krypton fluid mixtures using molecular dynamics simulation

We have performed molecular dynamics simulations to obtain internal energy and pressure of helium–neon and helium–krypton mixtures at different densities using accurate recently two-body ab initio potentials supplemented by quantum corrections following the Feynman–Hibbs approach. The significance of this work is that the three-body expression of Wang and Sadus [22] was used to improve prediction of the pressures and internal energies of helium + krypton and helium + neon mixtures without requiring an expensive three-body calculation. Our results show a good agreement with the corresponding experimental data.