Translational and rotational dynamics in liquids. comparison of experiment, kinetic theory and hydrodynamics

Ravi, R.; Ben‐Amotz, Dor

doi:10.1016/0301-0104(94)00023-9

Cited by 26 publications

(18 citation statements)

References 58 publications

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“…In general, 0 < C < 1, and if we use the experimental relaxation times and calculate C for the three bases, we obtain C(PYR) = 78.65 × 10 −3 , C(LUT) = 132.81 × 10 −3 , and C(TMP) = 80.00 × 10 −3 . Some authors 45,46 following the stick boundary condition find the hydrodynamic volume that best fits the experimental reorientational times. For the present cases, this would result in hydrodynamic volumes that are unreasonably small compared to their bulk liquid volumes at ambient conditions (in parentheses), V(PYR)= 10.54 Å 3 (133.77 Å 3 ), V(LUT) = 25.59 Å 3 (192.32 Å 3 ), and V(TMP) = 22.58 Å 3 (282.60 Å 3 ).…”

Section: ■ Introductionmentioning

confidence: 90%

Experimental and Theoretical Study of Molecular Response of Amine Bases in Organic Solvents

et al. 2014

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Reorientational correlation times of various amine bases (namely, pyridine, 2,6-lutidine, 2,2,6,6-tetramethylpiperidine) and organic solvents (dichloromethane, toluene) were determined by solution-state NMR relaxation time measurements and compared with predictions from molecular dynamics (MD) simulations. The amine bases are reagents in complex reactions catalyzed by frustrated Lewis pairs (FLP), which display remarkable activity in metal-free H2 scission. The comparison of measured and simulated correlation times is a key test of the ability of recent MD and quantum electronic structure calculations to elucidate the mechanism of FLP activity. Correlation times were found to be in the range of 1.4-3.4 (NMR) and 1.23-5.28 ps (MD) for the amines and 0.9-2.3 (NMR) and 0.2-1.7 ps (MD) for the solvent molecules.

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Section: ■ Introductionmentioning

confidence: 90%

Experimental and Theoretical Study of Molecular Response of Amine Bases in Organic Solvents

et al. 2014

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“…The ratio of the two diffusion coefficients is 0.46, which is lower than might be expected for a dimeric [{Zn(μ-bppSSbpp)} n ] 2n+ assembly (n = 2; theoretical monomer : dimer ratio ≈ 0.75) or an equilateral trimer (n = 3; monomer : trimer ratio ≈ 0.6), 42 but is significantly higher than has been measured for a cylindrical 16-mer assembly. 43 Assuming a stick solvent/solute relationship, 44 gave very similar results. Both complexes are almost completely high-spin at room temperature under these conditions, but exhibit the onset of a thermal spin equilibrium on cooling (Fig.…”

Section: Resultsmentioning

confidence: 80%

An iron(ii) spin-crossover metallacycle from a back-to-back bis-[dipyrazolylpyridine]

et al. 2015

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The syntheses of 4-mercapto-2,6-di(pyrazol-1-yl)pyridine (bppSH) and bis[2,6-di(pyrazol-1-yl)pyrid-4-yl]disulfide (bppSSbpp) are reported. In contrast to previously published "back-to-back" bis-[2,6-di(pyrazol-1-yl)pyridine] derivatives, which form coordination polymers with transition ions that are usually insoluble, bppSSbpp yields soluble oligomeric complexes with iron(ii) and zinc(ii). Mass spectrometry and DOSY data show that [{Fe(μ-bppSSbpp)}n](2n+) and [{Zn(μ-bppSSbpp)}n](2n+) form tetranuclear metallacycles in nitromethane solution (n = 4), although (1)H NMR and conductivity measurements imply the iron compound may undergo more fragmentation than its zinc congener. Both [{Fe(bppSH)2](2+) and [{Fe(μ-bppSSbpp)}n](2n+) exhibit thermal spin-crossover in CD3NO2 solution, with midpoint temperatures near 245 K. The similarity of these equilibria implies there is little cooperativity between the iron centres in the metallacyclic structures.

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“…To enhance the external diffusion, a mixed non-solvent with low viscosity is preferred, since the diffusion coefficient of a solvent is inversely proportional to its viscosity according to the Stocks-Einstein equation (See the Experimental Section, Supporting Information). [33] Then the mixed solvent should possess lower density than the casting solution to reduce the distortion of the interface caused by convection-driven via gravity. Therefore, in present work, n-heptane (HEP) was selected as one component of the mixed non-solvent due to its low viscosity and low density.…”

Section: Resultsmentioning

confidence: 99%

Membranes with Well‐Defined Selective Layer Regulated by Controlled Solvent Diffusion for High Power Density Flow Battery

Shi

Dai

et al. 2020

Advanced Energy Materials

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Membranes with precise control of selective layer are designed and prepared by adjusting diffusion of solvents. Combining experiments and theoretical calculations, the formation mechanism of ion conductive membranes prepared by a non‐solvent induced phase separation (NIPS) method is found to be related to internal diffusion flux of solvent to the non‐solvent bath and external diffusion flux of non‐solvent to the casting solution. By regulating the internal and external diffusion rates via a two‐step NIPS method, a series of polybenzimidazole (PBI) porous membranes with independently controlled thin selective skin layers and highly porous support layers are fabricated, which achieve a simultaneous improvement in ion selectivity and proton conductivity. A vanadium flow battery assembled with a PBI membrane demonstrates an energy efficiency of 80% at a current density of 220 mA cm−2, which is the highest value among the reported PBI membranes. This provides a simple and effective way to fabricate membranes with well‐defined morphologies.

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Translational and rotational dynamics in liquids. comparison of experiment, kinetic theory and hydrodynamics

Cited by 26 publications

References 58 publications

Experimental and Theoretical Study of Molecular Response of Amine Bases in Organic Solvents

Experimental and Theoretical Study of Molecular Response of Amine Bases in Organic Solvents

An iron(ii) spin-crossover metallacycle from a back-to-back bis-[dipyrazolylpyridine]

Membranes with Well‐Defined Selective Layer Regulated by Controlled Solvent Diffusion for High Power Density Flow Battery

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