Showing papers on "Tetrahydrofuran published in 2004"
TL;DR: The reaction of 2,2,3,3-tetrabromo-1,1,4, 4,4-tetrakis[bis(trimethylsilyl)methyl]-1, 4-diisopropyltetrasilane with four equivalents of potassium graphite (KC8) in tetrahydrofuran produces 1,1-4,4-, which shows half the magnitude of the bond shortening of alkynes compared with that
Abstract: The reaction of 2,2,3,3-tetrabromo-1,1,4,4-tetrakis[bis(trimethylsilyl)methyl]-1,4-diisopropyltetrasilane with four equivalents of potassium graphite (KC 8 ) in tetrahydrofuran produces 1,1,4,4-tetrakis[bis(trimethylsilyl)methyl]-1,4-diisopropyl-2-tetrasilyne, a stable compound with a silicon-silicon triple bond, which can be isolated as emerald green crystals stable up to 100°C in the absence of air. The SiSi triple-bond length (and its estimated standard deviation) is 2.0622(9) angstroms, which shows half the magnitude of the bond shortening of alkynes compared with that of alkenes. Unlike alkynes, the substituents at the SiSi group are not arranged in a linear fashion, but are trans-bent with a bond angle of 137.44(4)°.
467 citations
TL;DR: Results from molecular dynamics simulations of surfactant-solubilized subtilisin BPN' in three organic solvents (octane, tetrahydrofuran, and acetonitrile) and in pure water indicate that the behavior of hydration water on the enzyme surface and in the active site is an important determinant of biological function especially in low water media.
218 citations
TL;DR: By directed evolution, the activity of P450 BM‐3 in the presence of dimethylsulfoxide (DMSO) and tetrahydrofuran (THF) is improved, achieving increases in specific activity up to 10‐fold in 2% (v/v) THF and 6-fold in 25% DMSO.
Abstract: Cytochrome p450 BM-3 (EC 1.14.14.1) catalyzes the hydroxylation and/or epoxidation of a broad range of substrates, including alkanes, alkenes, alcohols, fatty acids, amides, polyaromatic hydrocarbons, and heterocycles. For many of these notoriously water-insoluble compounds, p450 BM-3's K(m) values are in the millimolar range. Polar organic cosolvents are therefore added to increase substrate solubility and achieve high catalytic efficiency. Using p450 BM-3 as a catalyst for these important transformations requires that we improve its ability to tolerate the cosolvents. By directed evolution, we improved the activity of p450 BM-3 in the presence of dimethylsulfoxide (DMSO) and tetrahydrofuran (THF), achieving increases in specific activity up to 10-fold in 2% (v/v) THF and 6-fold in 25% (v/v) DMSO. The engineered p450 BM-3's are also significantly more resistant to acetone, acetonitrile, dimethylformamide, and ethanol as cosolvents in the reaction.
187 citations
TL;DR: In this article, three novel magnesium aryloxides have been synthesized by the reaction of 2,2‘-methylenebis(4-chloro-6-isopropyl-3-methylphenol) (MCIMP−H2) with MgnBu2 in diethyl ether or tetrahydrofuran, respectively.
Abstract: Three novel magnesium aryloxides, [(MCIMP)2Mg2(THF)]2 (1), [(EDBP)Mg(Et2O)]2 (2), and [(EDBP)Mg(THF)]2 (3), have been synthesized by the reaction of 2,2‘-methylenebis(4-chloro-6-isopropyl-3-methylphenol) (MCIMP−H2) or 2,2‘-ethylidenebis(4,6-di-tert-butylphenol) (EDBP−H2) with MgnBu2 in diethyl ether or tetrahydrofuran, respectively. Experimental results show that 1−3 efficiently catalyze the ring-opening polymerization of e-caprolactone and l-lactide in a controlled fashion, yielding polymers with very narrow polydispersity indexes in a wide range of monomer-to-initiator ratios. Compound 1 has paved a way to synthesize as much as 500-fold polymer chains of poly(e-caprolactone) with a very narrow polydispersity index. In addition, block copolymers such as poly(e-caprolactone)-b-poly(l-lactide), poly(ethylene glycol) methyl ether-b-poly(l-lactide), and polystyrene-b-poly(l-lactide) have also been prepared.
125 citations
TL;DR: Although these nonaqueous solvates had higher solubility and dissolution rates than the monohydrous forms, they were unstable in aqueous media and rapidly transformed to one of the monhydrous forms.
Abstract: The purpose of the study was to characterize the physicochemical, structural, and spectral properties of the 1∶1 niclosamide and methanol, diethyl ether, dimethyl sulfoxide, N,N' dimethylformamide, and tetrahydrofuran solvates and the 2∶1 niclosamide and tetraethylene glycol hemisolvate prepared by recrystallization from these organic solvents. Structural, spectral, and thermal analysis results confirmed the presence of the solvents and differences in the structural properties of these solvates. In addition, differences in the activation energy of desolvation, batch solution calorimetry, and the aqueous solubility at 25°C, 24 hours, showed the stability of the solvates to be in the order: anhydrate > diethyl ether solvate > tetraethylene glycol hemisolvate > methanol solvate > dimethyl sulfoxide solvate > N,N' dimethylformamide solvate. The intrinsic and powder dissolution rates of the solvates were in the order: anhydrate > diethyl ether solvate > tetraethylene glycol hemisolvate > N,N' dimethylformamide solvate > methanol solvate > dimethyl sulfoxide solvate. Although these nonaqueous solvates had higher solubility and dissolution rates than the monohydrous forms, they were unstable in aqueous media and rapidly transformed to one of the monohydrous forms.
123 citations
TL;DR: In this paper, an emulsion technique was developed to determine the hydration number and the enthalpy of tetrahydrofuran (THF) and cyclopentane (CP) clathrate hydrates.
Abstract: Differential scanning calorimetry was applied to investigate the formation of tetrahydrofuran (THF) and cyclopentane (CP) clathrate hydrates. An emulsion technique was developed to determine the hydration number and the enthalpy of CP hydrate dissociation to liquid water and liquid cyclopentane, which were found to be 16.8 ± 0.7 and 82.3 kJ/mol CP, respectively. The hydration number corresponds to the theoretical number of 17 if all of the large cavities in the structure II hydrate are occupied. Experiments with water-in-CP emulsions did not identify homogeneous nucleation for the hydrate since ice and hydrate always formed together on supercooling. With water-in-heptane emulsions, for which no hydrate forms, the homogeneous ice supercooling limit was −37.8 °C. With the CP emulsion, ice and hydrate formed close to this temperature. For bulk THF/H2O solutions, even at the hydrate stoichiometric molar ratio of 1:17, ice and hydrate were found to form in the same crystallization event upon cooling, which imp...
105 citations
TL;DR: In this article, the electrochemical properties of surface films of deposited lithium on nickel substrates in electrolytes with LiN (SO 2 CF 3 ) 2 ) (LiTFSI), LiN(SO 2 C 2 F 5 ) 2 (LiBETI), LiPF 6 solutes, and tetrahydrofuran solvents were characterized by Fourier transform infrared, two-dimensional nuclear magnetic resonance (2D NMR), X-ray photoelectron spectroscopy, evolved gas analysis, and ion chromatograph in order to understand the electro
Abstract: Chemical components of surface films of deposited lithium on nickel substrates in electrolytes with LiN (SO 2 CF 3 ) 2 ) (LiTFSI), LiN (SO 2 C 2 F 5 ) 2 (LiBETI), LiPF 6 solutes, and tetrahydrofuran solvents were characterized by Fourier-transform infrared, two-dimensional nuclear magnetic resonance (2D NMR), X-ray photoelectron spectroscopy, evolved gas analysis, and ion chromatograph in order to understand the electrochemical performance of lithium imide/cyclic ether-based electrolytes The top layers of the surface film were ROCO 2 Li, Li 2 CO 3 , polymer constituents, and LiF The inner layers of the surface film consisted of Li 2 O and carbide species In imide/cyclic ether-based electrolytes, Li 2 S 2 O 4 and Li 2 SO 3 as outer layers, and Li 2 S as the inner layer were formed on a nickel substrate as reductive constituents of imide solute We found that organic surface layers consisted of lithium etoxides, lithium ethylene dicarbonate (CH 2 OCO 2 Li) 2 , polyethylene oxide, and lithium ethylene dicarbonate containing an oxyethylene unit by 1 H, 13 C, and 2D NMR Li cycling efficiency affects not only the deposited lithium morphology but also chemical components
104 citations
TL;DR: The linear-chain polymer [Tl[Au(C(6)Cl(5))(2)]](n), 1, reacts in the solid state and in solution with different volatile organic compounds and reveals a substantial participation of the metal atoms in transitions that give rise to the observed emissions.
Abstract: The linear-chain polymer {Tl[Au(C6Cl5)2]}n, 1, reacts in the solid state and in solution with different volatile organic compounds such as tetrahydrofuran, acetone, tetrahydrothiophene, 2-fluoropyridine, acetonitrile, acetylacetone, and pyridine. Solid-state exposure of 1 to vapors of the above VOCs produces a selective and reversible change in its color that is perceptible to the human eye and even deeper under UV irradiation, allowing 1 to function as a sensor for these VOCs. Heating the samples exposed to the VOCs for a few minutes at 100° C regenerates the original material without degradation, even after several exposure/heating cycles. The reversibility is further confirmed by X-ray powder diffraction measurements of complex 1 before and after exposure to vapors and again after heating the samples. The products obtained by reactions of complex 1 with the above VOCs as ligands in solution contain extended linear chains of alternating gold and thallium centers with two molecules of the organic ligands...
98 citations
TL;DR: In this article, the self-assembly of nonionic amphiphilic poly(ethylene oxide)-b-poly(e-caprolactone) (PEO-b-PCL) and poly(methyl-methyl-e-CAPOLACTONE) (PMCL) has been studied in water by dynamic light scattering (DLS), and the aqueous solutions have been prepared by three methods, i.e., dialysis of solutions in a common organic solvent against water, rapid addition of water to organic solutions, and rapid addition into water.
88 citations
TL;DR: In this paper, the authors show that gas-expanded liquids under CO2 pressure are unique media for amine formation and separation and demonstrate the potential for using modest pressures of CO2 to facilitate reactions as well as to separate products.
Abstract: Gas-expanded liquids are tunable media for reaction and separation. We report that gas-expanded liquids under CO2 pressure are unique media for amine formation and separation. In the heterogeneous hydrogenation of benzonitrile and phenylacetonitrile with NiCl2/NaBH4 in CO2-expanded ethanol, the primary amines are protected by CO2 so that the yield of the primary amines is greatly increased and the production of the secondary amines is effectively suppressed. In the homogeneous hydrogenation of benzonitrile and phenylacetonitrile with RhH(P-i-Pr3)3 and benzophenone imine with Rh(1,5-C8H12){P(C6H5)3}2]PF6 in CO2-expanded tetrahydrofuran, the primary amines are separated in situ in the form of solid carbamic acids and/or ammonium carbamates with increased yield while the catalyst remains in the solution. These results demonstrate the potential for using modest pressures of CO2 to facilitate reactions as well as to separate products.
83 citations
TL;DR: In this paper, four Chinese bituminous coals were extracted with CS 2, n -hexane, benzene, methanol, acetone, tetrahydrofuran (THF) and THF/methanol (1: 3 ǫ/vol) mixed solvent sequentially.
TL;DR: In this paper, a vanadium-dependent and vanadium independent reaction was proposed for the bromination of bis(homoally) alcohols with tert-butyl hydroperoxide (TBHP).
TL;DR: In this article, a simple mixture of water and tetrahydrofuran (THF) or 1,4-dioxane has been investigated by laser light scattering (LLS), and the results showed that PNIPAM swell in ether pure water or pure THF but fully collapse when [THF]:[water] = 0.05-0.15.
Abstract: The complexation of tetrahydrofuran as well as 1,4-dioxane with water has been investigated by laser light scattering (LLS). The complexation of cycloethers with water molecules makes the diffusion of water clusters visible in LLS. The intensity-intensity time correlation function of a simple mixture of water and tetrahydrofuran (THF) or 1,4-dioxane has two diffusive relaxation modes. The fast mode with a diffusion coefficient in the range 2-8 x 10 - 6 cm 2 s - 1 is related to mutual diffusion of the complexes formed between small water clusters and THF or 1,4-dioxane. The slow mode with a dynamic correlation length of 200-600 nm can be removed by filtration, indicating that the mixing of water and cycloethers is microscopically incomplete. Further, using a trace amount of spherical poly(N-isopropyl acryamide) microgels as probes, we indirectly investigated the water/THF interaction. Our results showed that PNIPAM swell in ether pure water or pure THF but fully collapse when [THF]:[water] = 0.05-0.15, in which the water/THF complexes are nonsolvent for PNIPAM. When [cycloether]:[water]> ∼0.16, water is not able to further complex with cycloethers added so that extra cycloethers exist as individual molecules to reswell the microgels, indicating that it is small water clusters, such as the pentamer and hexagon, that solvate PNIPAM.
TL;DR: In this article, the influence of the anion on the solubility of 1-butyl-3-methylimidazolium salts in dipropyl ether was tested.
TL;DR: In this paper, the neodymium trisborohydride Nd(BH 4 ) 3 - (THF) 3 was used as a catalyst precursor for isoprene polymerization for the first time.
Abstract: The neodymium trisborohydride Nd(BH 4 ) 3 - (THF) 3 (THF = tetrahydrofuran) has been used as a catalyst precursor for isoprene polymerization for the first time. Associated to an excess of Al(Et) 3 , the resulting catalyst is moderately active, giving a mixture of cis- and trans- polymer. Addition of a stoichiometric amount of MgBu 2 to Nd(BH 4 ) 3 (THF) 3 affords a stereospecific catalyst providing trans-1,4-polyisoprene, more than 96% regular. That dual component Nd/Mg system also shows a better efficiency and good control of the molecular weights. A molecular structure is tentatively attributed to a bimetallic active species, based on 1 H NMR experiments.
TL;DR: In this paper, the mechanism for the electrochemical reduction of titanocene dihalides, Cp2TiX2 (X = Cl, Br, I), in tetrahydrofuran has been described successfully using a common mesh scheme.
TL;DR: In this article, the authors characterized a distorted trigonal-bipyramidal structure with the THF ligands in trans position, which was confirmed by single-crystal X-ray diffraction.
TL;DR: Zinc powder was found to be a highly efficient catalyst for the synthesis of aromatic ethers using microwave heating in the presence of N,N-dimethylformamide as well as under stirring in an oil-bath using tetrahydrofuran as solvent without any inorganic base as discussed by the authors.
TL;DR: Using a laser monitoring observation technique, the authors determined the solubilities of paroxetine hydrochloride hemihydrate in N,N-dimethylformamide, methyl isobutyl ketone, tetrahydrofuran, ethyl acetate, methanol, ethanol, 1-propanol, 1butanol, and 2-butanol.
Abstract: Using a laser monitoring observation technique, we determined the solubilities of paroxetine hydrochloride hemihydrate in N,N-dimethylformamide, methyl isobutyl ketone, tetrahydrofuran, ethyl acetate, methanol, ethanol, 1-propanol, 1-butanol, and 2-butanol by the synthetic method from 286 K to 363 K. Results of these measurements were correlated by an empirical equation.
TL;DR: The Schlenk equilibrium involving RMgX, R2Mg, and MgX2 (R = Me, Et, Ph and X = Cl, Br) has been studied both in the gas phase and in diethyl ether (Et2O) and tetrahydrofuran (THF) solutions by means of the density functional theory (DFT) B3LYP/6-31+G* method as mentioned in this paper.
Abstract: The Schlenk equilibrium involving RMgX, R2Mg, and MgX2 (R = Me, Et, Ph and X = Cl, Br) has been studied both in the gas phase and in diethyl ether (Et2O) and tetrahydrofuran (THF) solutions by means of the density functional theory (DFT) B3LYP/6-31+G* method. Solvation was modeled using the supermolecule approach. The stabilization due to interaction with solvent molecules decreases in the order MgX2 > RMgX > R2Mg and among the groups (R and X) Ph > Me > Et and Cl > Br. Studied magnesium compounds are more strongly solvated by THF compared to Et2O. The magnesium halide is solvated with up to four solvent molecules in THF solution, assuming that trans-dihalotetrakis(tetrahydrofurano)magnesium(II) complex forms. The formation of cis-dihalotetrakis(tetrahydrofurano)magnesium(II) is energetically less favorable than the formation of corresponding disolvated complexes. The predominant species in the Schlenk equilibrium are RMgX in Et2O and R2Mg + MgX2 in THF, which is consistent with experimental data.
TL;DR: The transient organoindium intermediates formed in the reaction of propargyl bromide with indium in aqueous media and tetrahydrofuran were investigated by NMR spectroscopy and found to be allenylindium(I) and allenylon(III) dibromide.
Abstract: The transient organoindium intermediates formed in the reaction of propargyl bromide with indium in aqueous media and tetrahydrofuran were investigated by NMR spectroscopy and found to be allenylindium(I) and allenylindium(III) dibromide. The influence of solvent and methyl substitution on the propargyl-allenylindium system was also studied. The experimental observations were supported by theoretical calculations using the B3LYP/6-311+G* method.
TL;DR: Reaction with TMSOTf in MeCN at room-temperature effected C-glycosylation to provide the alpha-allyl-C-mannosyl product 18 with excellent stereoselectivity, and crossover experiments proved that reaction was proceeding via an intermolecular pathway rather than the hoped-for intramolecular delivery route.
Abstract: Methyl mannoside 16 containing an allyldimethylsilyl ether at C(2) was synthesized in nine steps from D-mannose. Reaction with TMSOTf in MeCN at room-temperature effected C-glycosylation to provide the alpha-allyl-C-mannosyl product 18 with excellent stereoselectivity. Crossover experiments over a range of reaction concentrations proved that reaction was proceeding via an intermolecular pathway rather than the hoped-for intramolecular delivery route. The exceptionally high stereoselectivity of this allylation in the presence of an acid-scavenger, 2,6-DTBMP, can be attributed to the allylsilyl ether 16 behaving as the allylating agent. Geometrical constraints in the seven-membered ring transition state account for the lack of intramolecular allyl transfer. Attaching a modified allylsilane 29a-c to C(2)OH of methyl mannoside 15 improved matters. Reaction of the tethered mannosides 27a-c with TMSOTf in the presence of 2,6-DTBMP in MeCN at rt provided a range of products, which depended on the size of the alkyl substituents at the silyl ether tether. Diene products were the major compounds irrespective of the size of the alkyl substituents at the silyl ether tether. Their formation can be understood by intramolecular allylation of the allylsilane on to the activated anomeric center, followed by collapse of the intermediate carbocation by preferential attack of an external nucleophile at the silyl ether tether, rather than at the allylic silicon center. A cascade of further reactions rationalizes the formation of the 2-dienyl-substituted tetrahydrofuran 30 and dienes 39 and 40. The desired beta-allyl-C-mannosyl products 42 and 43 were obtained, albeit in low yield, when bulky ethyl and isopropyl groups were employed at the silyl ether tether. Stereospecific oxidative cleavage of the silyl tether in 42 and 43 provided the corresponding stereodefined diols 44 and 45, respectively. Attempts to improve the yield and diastereoselectivity of the desired beta-allyl-C-mannosyls by moving to a sulfoxide mannosyl donor, which could be activated at low temperature, proved unsuccessful.
TL;DR: NMR spectroscopic studies have been performed on the mixed complexes formed by the lithium salt of acetonitrile and the chiral lithium amides in diethyl ether and tetrahydrofuran solvent, where the dimer undergoes fast exchange between ketenimine and bridged structures and the complex appears C(2)-symmetric on the N MR spectroscopy time scale.
Abstract: NMR spectroscopic studies have been performed on the mixed complexes formed by the lithium salt of acetonitrile (LiCH2CN) and the chiral lithium amides Li−(S)-N-(2-methoxybenzyl)-1-amino-1-phenyl-2-ethoxyethane (Li-1) and Li−(S)-N-isopropyl-2-amino-1-phenyl-3-methoxypropane (Li-2) in diethyl ether and tetrahydrofuran solvent. In diethyl ether Li-1 and LiCH2CN form a mixed dimeric (1:1) complex, while Li-2 and LiCH2CN form a mixed trimeric (2:1) complex. The dimer undergoes fast exchange between ketenimine and bridged structures. Both 1J(15N,6Li) and 1J(13C,6Li) couplings were observed for the respectively isotopically labeled compounds. In the trimeric complex the CH2CN anion also undergoes fast degenerate exchange between ketenimine and bridged structures, and the complex appears C2-symmetric on the NMR spectroscopy time scale. Both the dimer and trimer complexes have the bridged acetonitrile anion in common, as indicated by the highly shielded α-carbon 13C NMR shifts (δ −6.1 and −7.4, respectively). In ...
TL;DR: In this article, a diimide-diacid chloride (3) containing a noncoplanar 2,2′-dimethyl-4,4′-biphenylene unit was synthesized by using trimellitic anhydride followed by refluxing with thionyl chloride.
Abstract: A new diimide–diacid chloride (3) containing a noncoplanar 2,2′-dimethyl-4,4′-biphenylene unit was synthesized by treating 2,2′-dimethyl-4,4′-diamino-biphenylene with trimellitic anhydride followed by refluxing with thionyl chloride. Various new poly(ester-imide)s were prepared from 3 with different bisphenols by solution polycondensation in nitrobenzene using pyridine as hydrogen chloride quencher at 170°C. Inherent viscosities of the poly(ester-imide)s were found to range between 0.31 and 0.35 dL g−1. All of the poly(ester-imide)s, except the one containing pendent adamantyl group 5e, exhibited excellent solubility in the following solvents: N,N-dimethylformamide, tetrahydrofuran, tetrachloroethane, dimethyl sulfoxide, N,N-dimethylacetamide, N-methyl-2-pyrrolidinone, m-cresol, o-chlorophenol, and chloroform. The polymers showed glass-transition temperatures between 166 and 226°C. The 10% weight loss temperatures of the poly(ester-imide)s, measured by TGA, were found to be in the range between 415 and 456°C in nitrogen. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2486–2493, 2004
TL;DR: In this paper, the tetrahydropyranyl (THP) group was efficiently removed using PdCl 2 (CH 3 CN) 2 as catalyst in CH 3 CN, while other protection groups such as p -toluenesulfonyl (Ts), tert-butyldiphenylsilyl (TBDPS), benzyloxycarbonyl, allyl, benzyl (Bn), and benzoyl (Bz) remained intact under these conditions.
TL;DR: In this paper, the determination of absolute molar mass averages (MMA) and molar distribution (MMD) of the fourth generation hyperbranched polyester Boltorn H40 (Perstorp Specialty Chemicals AB), synthesized from 2,2-bis(methylol)propionic acid (bis-MPA) as the AB2 monomer and ethoxylated pentaerythritol as the B4 core molecule was studied in dependence on the type of solvent, preparation procedure and solution concentration.
TL;DR: In this paper, the vapor-hydrate equilibria were measured for CH 4 + C 2 H 6 + tetrahydrofuran (THF) + water systems in the temperature range of 274.15-282.15 K, pressure range of 1.0-3.0 MPa and THF concentration range of 4-14% in initial aqueous solution.
TL;DR: In this paper, a series of photosensitive hyperbranched polyimides (HB-PIs) were prepared through facile end-group modifications of the fully imidized polymer.
Abstract: A series of photosensitive hyperbranched polyimides (HB-PIs) were prepared through facile end-group modifications of the fully imidized polymer. A triamine, 1,3,5-tris(4-aminophenoxy)benzene, and a dianhydride, 4,4′-(hexafluoroisopropylidene)diphthalic anhydride, were condensed with a dropwise addition method in a molar ratio of 1/2 to afford an anhydride-terminated poly(amic acid) precursor, which was then end-capped by 4-aminophenol and chemically imidized to yield a phenol-terminated HB-PI. The modifications of the terminal phenol groups of the polyimide by acyl chloride compounds (acryloyl chloride, methylacryloyl chloride, and cinnamoyl chloride) gave the target polymers. The photosensitive HB-PIs showed good thermal properties and excellent solubility even in low-boiling-point solvents at room temperature, such as acetone, 1,1,2-trichloroethane, tetrahydrofuran, and chloroform. Photosensitive property studies revealed good photolithographic properties with a resolution greater than 3 μm and a sensitivity of 650–680 mJ/cm2. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1735–1744, 2004
TL;DR: In this article, the reaction of primary and secondary alcohols with tetrahydrofuran and a catalytic amount of 1- tert -butylperoxy-1,2-benziodoxol-3(1 H )-one in the presence of carbon tetrachloride at 50°C provides an efficient method for protecting the hydroxy group as 2-tetrahedrofuranyl ethers.
TL;DR: In this paper, the selfaggregation of TBA forms dominant cluster structures, and the hydrogen-bonded water clusters are disintegrated with increasing X T B A ≥ 0.3.
Abstract: The cluster structures observed by means of mass spectrometry for binary mixtures-tert-bulyl alcohol (TBA)-H 2 O and tetrahydrofuran (THF)-D 2 O-with varying mixing ratios exhibit striking contrast, even though both TBA andTHF are miscible with water at any mixing ratio. In the TBA-H 2 O mixtures at TBA mole fractions of (X T B A ) ≤ 0.01-0.025, some of the H 2 O molecules in the H 2 O clusters are replaced by TBA molecules. For 0.01-0.025 ≤ X T B A ≤ 0.2-0.3, the self-aggregation of TBA forms dominant cluster structures, and the hydrogen-bonded water clusters are disintegrated with increasing X T B A . This TBA self-aggregation is reduced with further increasing TBA at X T B A ≥ 0.3. However, in the THF-D 2 O mixtures, THF molecules have a weak additional interaction with D 2 O clusters, and the self-aggregation of THF is not promoted in the THF-D 2 O mixtures. The D 2 O clusters still exist, even at a THF mole fraction of X T H F = 0.3. On the basis of the observed cluster structure, the mechanism for the mixing between water and the organic solvent and the controlling factors in the self-aggregation are proposed.