Modeling and extractive properties of quaternary salt in a two‐phase system

Wu, Ho‐Shing; Tseng, Ming-Shu

doi:10.1002/aic.690480420

Cited by 10 publications

(10 citation statements)

References 35 publications

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“…It is demonstrated that the lower active site density in the resin could give a higher reactivity of allylation of phenol (Figures 4b and 4d), that is, the reactive microenvironment in the resin with lower active site density was good. This finding corresponds to the result of previous studies, which found that the solvating capability between quaternary salt and water could reduce the quaternary salt's reactivity in the organic phase in a phase‐transfer‐catalyzed reaction 18, 19. Thus, too much water content in the interior of the catalyst would reduce the reactivity of the allylation of phenol.…”

Section: Resultssupporting

confidence: 90%

Catalytic kinetics of quaternary ammonium poly(styrene‐co‐methylstyrene) resin

Lin

2006

AIChE Journal

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(methanol, ethyl alcohol, and DMF), and kinds of tertiary amines (trimethylamine, triethylamine, tripropylamine, trin-butylamine, tri-n-pentylamine, tri-n-hexylamine, and tri-n-octylamine). These catalysts were used to achieve the optimum allylation of phenol. The reactions were conducted and studied individually with either equal mole or equal weight of catalyst. The best reactivity for the allylation of phenol was obtained when the structure of the quaternary ammonium catalyst was 10% degree of ring substitution and 2% degree of crosslinkage activating with trihexylamine. The turnover number and the effectiveness factor were also calculated.

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Section: Resultssupporting

confidence: 90%

Catalytic kinetics of quaternary ammonium poly(styrene‐co‐methylstyrene) resin

Lin

2006

AIChE Journal

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“…[3] They are used as interacting reagents in separation techniques (HPLC [4] or capillary electrophoresis [5] ) and are also involved in biphasic processes, such as phase-transfer catalysis [6] or reactive extraction. [7] In liquid-liquid systems quaternary ammonium salts, which are known for their ability to form hydrophobic IPs with organic and inorganic anions in water, are used as anion carriers. In a recent study, [8] we analyzed the behavior of mixtures of tetraalkylammonium bromides (TAABs) of increasing chain lengths [alkyl = methyl (TMAB), ethyl (TEAB), propyl (TPAB), and butyl (TBAB)] with an anionic surfactant, sodium dodecyl sulfate (SDS).…”

Section: Introductionmentioning

confidence: 99%

Amphiphilic Organic Ion Pairs in Solution: A Theoretical Study

2007

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The macroscopic manifestation of hydrophobic interactions for amphiphilic organic ion pairs (tetraalkylammonium-anion) has been shown experimentally by measuring their association constants and their affinity with the organic phase. Beyond a certain size, there is a direct relation between association constants and chain lengths in tetraalkylammonium ions. We propose to cast a bridge between these results and geometrical properties considered at the level of a single ion pair by means of quantum chemistry calculations performed on model systems: trimethylalkylammonium-pentyl sulfate instead of tetraalkylammonium-dodecyl sulfate. Two limiting cases are considered: head-to-head configurations, which yield an optimal electrostatic interaction between polar heads, and parallel configurations with a balance between electrostatic and hydrophobic interactions. All properties (geometries, complexation energies, and atomic charges) were obtained at the MP2 level of calculation, with water described by a continuum model (CPCM). Dispersion forces link hydrocarbon chains of tetraalkylammonium ions and pentyl sulfate, thus yielding (for the largest ion pairs) parallel configurations favored with respect to head-to-head geometries by solute-solvent electrostatic interactions. Given the small experimental association energies, we probe the accuracy limit of the MP2 and CPCM methods. However, clear trends are obtained as a function of chain length, which agree with the experimental observations. The calculated monotonic stabilization of ion pairs when the hydrocarbon chain increases in length is discussed in terms of electrostatic interactions (between ions and between ion pairs and water), dispersion forces, and cavitation energies.

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“…Sometimes, other processes may occur like dimerisation, 9 heteroconjugation, 10 , or aggregation. 11 The characteristics of such systems arise essentially from the coupling between bi-molecular (like association/dissociation) and monomolecular processes (like partition of the same species between the two phases). This is the reason why in this study we focus on the case where only one dissociation occurs in one phase or in both.…”

Section: Introductionmentioning

confidence: 99%

Partition of dissociable compounds in two‐phase liquid systems: a theoretical and experimental study

Pradines¹,

Despoux²,

Claparols³

et al. 2006

J of Physical Organic Chem

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The partition at equilibrium, in a two-phase liquid system, of a compound dissociated in one phase, or both, is expressed in terms of general equations and analyzed. Dissociation in the second phase, even weak, has a nonnegligible influence. The distribution ratio depends strongly on the concentration and can even be reversed in certain cases. All the partition and dissociation constants in each phase can be obtained from the concentrations at equilibrium measured under some given conditions. In less favorable cases, an apparent partition constant can still be estimated. This is illustrated by an experimental study, in the water/dichloromethane system, involving the partition of picric acid and cetyltrimethylammonium bromide (CTAB) followed by UV-Visible spectroscopy, and of a series of tetraalkylammonium bromides (ethyl, propyl, and butyl) assayed by mass spectroscopy.

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Modeling and extractive properties of quaternary salt in a two‐phase system

Cited by 10 publications

References 35 publications

Catalytic kinetics of quaternary ammonium poly(styrene‐co‐methylstyrene) resin

Catalytic kinetics of quaternary ammonium poly(styrene‐co‐methylstyrene) resin

Amphiphilic Organic Ion Pairs in Solution: A Theoretical Study

Partition of dissociable compounds in two‐phase liquid systems: a theoretical and experimental study

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