Pure Organic Solvents Research Articles

Solubility and Dissolution Thermodynamics of 1,1-Bis(3-methyl-4-hydroxyphenyl)cyclohexane (MeBZ) in Different Pure Organic Solvents in the Temperature Range from 299.15 to 328.15 K

The solubility of 1,1-bis(3-methyl-4-hydroxyphenyl)cyclohexane (MeBZ) in different pure organic solvents such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, acetone, 1,4-dioxane, ethylacetate, and tetrahydrofuran over a temperature range from 299.15 to 328.15 K at atmospheric pressure were measured by gravimetric method. The solubility increased significantly with increase in temperature in all studied solvents. Among the studied solvents, tetrahydrofuran showed the highest solubility at 328.15 K. The experimental solubilities were corelated with the modified Apelbalt equation and Buchowski–Ksiazczak (λh) equation.The thermodynamic parameters such as enthalpies of solution ( $$\Delta H_{{{\text{sol}}}}^{^\circ }$$ ), Gibbs energy of dissolution ( $$\Delta G_{{{\text{sol}}}}^{^\circ }$$ ), isobaric heat capacity( $$\Delta C_{{p\;{\text{sol}}}}^{^\circ }$$ ), and entropy of solutions ( $$\Delta S_{{{\text{sol}}}}^{^\circ }$$ ) were calculated using Clark and Glew equation.

Photochemical Upconversion in Water Using Cu(I) MLCT Excited States: Role of Energy Shuttling at the Micellar/Water Interface

Photochemical upconversion (UC) through triplet-triplet annihilation (TTA), which employs a visible absorbing triplet photosensitizer and an annihilator, is a process that generates a high energy photon from two lower energy photons. TTA-UC has been largely developed in pure organic solvents and solid-state polymeric constructs while featuring near exclusive use of rare and expensive metals within the photosensitizer. In this current investigation, we demonstrate that TTA-UC from the long lifetime earth-abundant photosensitizer [Cu(dsbtmp)2](PF)6 (dsbtmp = 2,9-di(sec-butyl)-3,4,7,8-tetramethyl-1,10-phenanthroline), abbreviated as Cu-PS, functions in water through encapsulation within a cationic-based assembly. Cetyltrimethylammonium bromide was the surfactant of choice as it electrostatically binds the negatively charged water-soluble 10-phenylanthracene-9-carboxylate (PAC) acceptor/annihilator and ultimately facilitates energy transfer across the interface. Efficient triplet-triplet energy transfer (TTET) from Cu-PS to the PAC acceptor was achieved in this aqueous assembly. Unfortunately, the hindered mobility of the PAC moieties ultimately hampered the annihilation process, and this was reflected in attenuated TTA rates and efficiencies. The combined experimental data illustrated that the water-soluble PAC acceptor was able to vectorially deliver the excited-state energy stored in Cu-PS across the interface into the bulk aqueous solution by engaging in excited-state electron transfer with methyl viologen acceptors. These results are important for remotely operating photoredox reactions in water while rendering a photosensitizer spatially isolated in the hydrophobic core of a micelle.

The solubility and dissolution thermodynamic properties of chloroquine diphosphate in different organic solvents

Due to the currently commercial process for production of chloroquine diphosphate with certain disadvantages, there is need to select relevant solvents and to design an optimized production process. The dissolution process of chloroquine diphosphate (form II) in different solvents within the temperature range from 273.15 K to 313.15 K is studied by using the isothermal equilibrium method. Most information in pure solvents is in DMF (3.781 × 10−5 in mole fraction) at 313.15 K, followed by ethanol (2.426 × 10−5), n-propanol (1.153 × 10−5) and isopropanol (8.20 × 10−6). In mixtures of isopropanol (1-w) + DMF (w), the solubility values increase monotonically with the increasing mass fraction (w) of DMF. However, in the system of ethanol (1-w) + DMF (w), solubility increases first, and then decreases with the composition as DMF increases. The maximum value is (4.466 × 10−5) at w = 0.40 at 313.15 K, an increase about 2 fold. The solubility process depends on the chemical properties of solvent such as the hydrogen bond acidity (α), hydrogen bond basicity (β), dipolarity/polarizability (π*) and the Hildebrand solubility parameter (δ2 H), which are discussed. Moreover, the solubility results are evaluated by the modified Apelblat equation and Jouyban-Acree model, and the values of relative average deviation (RAD) are all less than 1.11% in pure organic solvents, and no more than 4.03% in two mixtures. Besides, the calculation of apparent thermodynamic analysis indicates that the dissolution is an endothermic, spontaneous and entropy driven process.

Crystal Structure, Hirschfeld Surface Analysis, and Absorption Spectra of a New Polymorph of Highly Symmetric Tetraphenylporphyrinato Zn(II), ZnTPP

The crystal and molecular structure of a new polymorph of four-coordinated Zn(II) tetraphenylporphyrin, with formula ZnTPP (TPP = 5,10,15,20-tetraphenyl porphyrin) has been determined from 3D X-ray diffraction data. The new polymorph crystallizes in the tetragonal space group, I4/m with cell dimensions a = 13.4206(9), c = 9.7210(16) A, V = 1750.9(3) A3, and Z = 4. The previous polymorph was crystallized in triclinic space group, P $$\bar {1}$$ . The single crystal of toluene solvate, a pseudopolymorph of tetraphenylporphinatozinc(II), ZnTPP ⋅ 2C7H8 was also crystallized in the triclinic space group, P $$\bar {1}$$ . The porphyrin cores of all the three centrosymmetric crystalline forms adopt a planar conformation which is attributed to the equivalent size of Zn2+ cations and that of porphyrin cores. In contrast to the two previous triclinic structures, which have two crystallography unique pyrrole rings, the tetragonal structure in the present form has all the pyrrole rings symmetric in nature. Further the symmetric orientations of phenyl rings about the mean N4 plane in the present form, unlike the two previous triclinic forms in which phenyl rings makes two types of dihedral angles with mean N4 plane reflects that the tetragonal structure of ZnTPP is the highly ordered geometry. All the four Zn–N bond distances in the present form are equal i.e., 2.048(2) A and is slightly longer than the average Zn–N bond distances found in the previous triclinic forms. The 3D packing of present form features sandwich type or face to face stacked layers that are bridged by a body centred molecule. The crystal packing is mainly stabilised by C–H⋅⋅⋅C and H⋅⋅⋅H intermolecular forces. Further the role and nature of various intermolecular interactions were quantitatively analysed by 3D Hirschfeld surface analysis and associated 2D fingerprint plots. The optical absorption spectra of ZnTPP and its free base analog, H2TPP have been further analysed in pure organic solvents of CH2Cl2 and CH3OH at different ionic strengths of the media and their results have been discussed in detail.

Reappraisal of Empirical Solvent Polarity Scales for Organic Solvents

AbstractCorrelations of Reichardt'sET(30), the CatalánSdP(solvent dipolarity),SP(solvent polarizability),SA(solvent acidity),SB(solvent basicity), Kamlet‐Taftπ* (dipolarity/polarizability),α(hydrogen bond donating ability) andβ(hydrogen bond accepting ability) polarity parameters with the molar concentration of 161 pure organic solvents are presented. Mostly, linear relationships of the polarity parameter as a function of molar concentration are obtained as long as each individual solvent class is considered separately. A physically different interpretation of theET(30), Kamlet‐Taftπ* andαas well as CatalánSAandSBparameters has been proposed. Furthermore, the Hildebrand solubility parameter in combination with the diffraction index is used for the correlation analysis with the above‐mentioned solvent parameters. It can be concluded that empirical polarity parameters derived from solvatochromic UV/Vis measurements are inherently a function of the molecular structure of the probe.

A Stable 3D Zn-Coordination Polymer Sensor Based on Dual Luminescent Ligands for Efficient Detection of Multiple Analytes under Acid or Alkaline Environment.

A novel 3D luminescent coordination polymer (LCP) [Zn4(3-dpyb)2(odpa)2(H2O)3]·4H2O (1) (3-dpyb = N,N'-bis (3-pyridinecarboxamide)-1,4-butane, H4 odpa = 4, 4'-oxidiphthalic acid) was successfully synthesized under solvothermal conditions. LCP 1 displays remarkable fluorescent behavior and stability in a wide range of pH values and different pure organic solvents. More importantly, LCP 1 can become an outstanding candidate in the selective sensing of Fe3+, Bi3+, Cr2O72-, MnO4-, nitrobenzene (NB), acetaldehyde (AH), and acetylacetone (Hacac) under a lower detection limit. The change process of fluorescent intensity of these seven analytes in a diverse pH range indicates that LCP 1 can be an excellent luminescent sensor in multiple acid/base solutions. As far as we know, it is an infrequent example of a CP-based multiresponsive fluorescent sensor for metal cations, oxyanions, and toxic organic solvents under an acid or alkaline environment.

Determination and Correlation of Solubility of Forms I and II of Imidacloprid in Seven Pure Solvents from 293.15 to 333.15 K

The solubility of two forms of imidacloprid, forms I and II, in seven pure organic solvents was measured using the analytical gravimetric method. It was shown that the solubility of the two forms o...

Thermodynamic Models for Determination of Solid–Liquid Equilibrium of the Sarafloxacin Hydrochloride in Pure and Binary Organic Solvents from (278.15 to 333.15) K

In this study, the gravimetric method was taken to measure the solubility of the sarafloxacin hydrochloride under atmospheric pressure in methanol, isopropanol, ethanol, 1-butanol, acetonitrile, n-...

Solubility Measurement and Data Correlation of Thiabendazole in 12 Pure Organic Solvents from 283.15 to 323.15 K

The solubility of thiabendazole (TBZ) in 12 organic solvents (methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, acetone, butanone, methyl acetate, ethyl acetate, n-butyl acetate, a...

Quaternized Chitosan Nanoparticles in Vaccine Applications.

Different natural and synthetic biodegradable polymers have been used in vaccine formulations as adjuvant and delivery system but have faced various limitations. Chitosan is a new delivery system with the potential to improve development of nano vaccines and drugs. However, chitosan is only soluble in acidic solutions of low concentration inorganic acids such as dilute acetic acid and dilute hydrochloric acid and in pure organic solvents, which greatly limits its application. Chemical modification of chitosan is an important way to improve its weak solubility. Quaternized chitosan not only retains the excellent properties of chitosan, but also improves its water solubility for a wider application. Recently, quaternized chitosan nanoparticles have been widely used in biomedical field. This review focuses on some quaternized chitosan nanoparticles, and points out the advantages and research direction of quaternized chitosan nanoparticles. As shown by the applications of quaternized chitosan nanoparticles as adjuvant and delivery carrier in vaccines, quaternized chitosan nanoparticles have promising potential in application for the development of nano vaccines in the future.

Experimental and Modeling of Conductivity for Electrolyte Solution Systems.

Studying the concentration and temperature dependence of the conductivity of electrolyte solution is of great significance for the evaluation and improvement of the performance of the electrochemical system. In this paper, based on the influence of the number of free ions and ion mobility on the conductivity, a semiempirical conductivity model with five parameters was proposed to correlate the conductivity, concentration and temperature data of electrolyte solutions at medium and high concentrations. The conductivities of NaCl and CaCl2 in propylene carbonate–H2O binary solvents were measured at temperatures varying from 283.15 to 333.15 K. The validity of the model was verified by the experimental data of this paper and the conductivity, concentration, and temperature data of 28 electrolyte solution systems in the literature. The electrolyte solutions investigated in this paper included binary organic solvent systems, pure organic solvent systems, and aqueous solution systems. The results showed that the proposed model can fit the experimental data well for both pure solvent and mixed solvents systems, which is of great value to practical engineering applications.

Efficient Chemo-Enzymatic Flow Synthesis of High Value Amides and Esters

A flow-based chemo-enzymatic synthesis of selected APIs (i.e., butacaine, procaine and procainamide) has been developed. A bioreactor made of MsAcT, a versatile acyltransferase from Mycobacterium smegmatis, immobilised on glyoxyl–garose, was exploited to efficiently prepare amide and ester intermediates in gram scale. Immobilised MsAcT was employed in pure organic solvent, demonstrating high stability and reusability. In-line purification of the key intermediates using polymer-bound sulphonyl chloride was added after the bioreactor, enhancing the automation of the process. A final hydrogenation step using the H-Cube reactor was further carried out to obtain the selected APIs in excellent yields (>99%), making the process fast, safe and easily handled.

Saturated Solubility of 2-Acrylamide-2-methylpropanesulfonic Acid in 14 Neat Organic Solvents from 283.15 to 328.15 K

This investigation was devoted to the saturated solubility of 2-acrylamide-2-methylpropanesulfonic acid in 14 pure organic solvents, namely, ethyl acetate, methanol, 1,4-dioxane, ethanol, isopropan...

Thermodynamics of the Enantiotropic Pharmaceutical Compound Benzocaine and Solubility in Pure Organic Solvents

The thermodynamic relationship between FI and FII of ethyl 4-aminobenzoate (benzocaine) has been investigated. Slurry conversion experiments show that the transition temperature below which FI is stable is located between 302 K–303 K (29 °C–30 °C). The polymorphs FI and FII have been characterised by infrared spectroscopy (IR), Raman spectroscopy, transmission powder X-ray diffraction (XRPD) and differential scanning calorimetry (DSC). The isobaric solid state heat capacities have been measured by DSC. The quantitative thermodynamic stability relationship has been determined in a comprehensive thermodynamic analysis of the calorimetric data. The solubility of both polymorphs has been determined in eight pure organic solvents over the temperature range 278 K–323 K by a gravimetric method. The mole fraction solubility of benzocaine decreases in the order: 1,4-dioxane, acetone, ethyl acetate, chloroform, acetonitrile, methanol, n-butanol and toluene. Comparison with the determined activity of solid benzocaine forms shows that negative deviation from Raoult's law ideality is found in dioxane, acetone and ethyl acetate solutions, and positive deviation in solutions of the other investigated solvents.

Characterization of Selected Polymeric Membranes Used in the Separation and Recovery of Palladium-Based Catalyst Systems.

Membrane separation processes tender a capable option for energy-demanding separation processes. Nanofiltration (NF) and reverse osmosis (RO) membranes are among the most explored, with a latent use in the chemical industry. In this study, four commercial membranes (NF90, NF270, BW30, and XLE) were investigated for their applicability based on the key structural performance characteristics in the recycling of Pd-based catalysts from Heck coupling post-reaction mixture. Pure water and organic solvent permeabilities, uncharged solute permeability, swelling, and catalyst rejection studies of the membranes were conducted as well as the morphological characterization using Fourier transform infrared, field emission gun scanning electron microscopy, and atomic force microscopy. Characterization results showed trends consistent with the manufactures’ specifications. Pure water and organic solvent fluxes generally followed the trend NF270 > NF90 > BW30 > XLE, with the solvent choice playing a major role in the separation process. Pd(PPh3)2Cl2 was well rejected by almost all membranes in 2-propanol; however, XLE rejects Pd(OAc)2 better at high pressure in acetonitrile. Our study, therefore, revealed that the separation and reuse of the two catalysts by NF90 at 10 bar resulted in 97% and 49% product yields with 52% and 10% catalyst retention for Pd(OAc)2 while Pd(PPh3)2Cl2. gave 87% and 6% yields with 58% and 36% catalyst retention in the first and second cycles, respectively. Considering, the influence of membrane–solute interactions in Pd-catalyst rejection, a careful selection of the polymeric membrane and solvent, a satisfactory separation, and recovery can be achieved.

Influence of particle type and concentration on the ultrafiltration behavior of nanoparticle stabilized Pickering emulsions and suspensions

In recent years, Pickering emulsions (PE) have become of increasing interest for their application in (bio-) catalytic multiphase processes. To design an economically feasible process, an efficient and effective catalyst recovery is necessary. Ultrafiltration of PE has been shown to be a promising procedure. In this work, the influence of drop size distributions and rheology on the ultrafiltration of water-in-oil and oil-in-water PE stabilized by different nanoparticles as well as organic solvent-nanoparticle suspensions was studied.Particles with higher hydrophobicity led to larger Sauter mean diameters. Depending on the ability of silica particles to form three-dimensional network structures, shear thinning or Newtonian rheological behavior was obtained. When suspensions of particles with gelling properties were filtered, an increase in flux compared to the filtration of the pure organic solvent was observed. Water-in-oil PE showed – regardless of investigated particle type and concentration – a disproportionate increase of flux with pressure. However, adjusting the membrane pre-treatment procedure led to a linear dependency between flux and pressure, which was also observed for oil-in-water PE (without special pre-treatment).This work shows that the ultrafiltration of PE made from various nanoparticles is possible and contributes to a better understanding of PE characteristic properties and their influence on the ultrafiltration behavior.

Microfluidic water-assisted trap focusing method for ultra-large volume injection in reversed-phase nano-liquid chromatography coupled to electron ionization tandem-mass spectrometry

Herein we present an efficient, column-switching method that relies on a custom-made T-union passive diffusion micromixer to assist water dilution and promote trap solute focusing of a high sample volume dissolved in pure organic solvent using a 0.075mm i.d. nano-LC column. This method allows injecting 20 μL (or higher) of sample volume, speeding up the analysis time, with a 400-fold increase of the limits of quantitation for selected compounds. Five pesticides in different media were used as model compounds, and the analyses were carried out with a triple quadrupole mass spectrometer equipped with a Liquid Electron Ionization (LEI) LC-MS interface working in multiple reaction monitoring (MRM) mode. The system microfluidics were investigated using COMSOL modeling software. Robustness of the entire system was evaluated using a post-extraction addition soil extracts with limits of detection values spanning from 0.10 to 0.45µg/L. Reproducible results in terms of peak area, peak shape, and retention times were achieved in soil matrix. Repeatability test on peak area variations were lower than 10%.

HILIC characterization: Estimation of phase volumes and composition for a zwitterionic column

A methodology for the estimation of the different phase volumes in HILIC is presented. For a ZIC-HILIC column the mobile phase volume (hold-up volume) is determined in several acetonitrile- and methanol-water compositions by a Linear Free Energy Relationships (LFER) homologous series approach involving n-alkyl-benzenes, -phenones, and -ketones. We demonstrate that the column works as a HILIC column when the mobile phase contains high and medium proportions of methanol or acetonitrile. However, for acetonitrile contents below 20%, or 40% for methanol, same column works in RPLC. In between, a mixed HILIC-RPLC behavior is observed, and solutes of low molecular volume are retained as in HILIC mode, but the largest ones show RPLC retention. From the homologous series retention data and pycnometric measurements involving the pure organic solvents and their mixtures with water, the mean solvent composition of the water-rich transition layers between column functionalization and the bulk mobile phase, which act as stationary phase, is estimated. Finally, the phase ratio between stationary and mobile phases is also estimated for each eluent composition, allowing the calculation of the corresponding stationary phase volumes. All volumes are strongly dependent on the water content in the eluent, especially when acetonitrile is selected as mobile phase constituent. In HILIC mode, when the water content in the hydroorganic mobile phase increases, the volumes of mobile phase decrease, but the volumes of stationary phase (mainly the water layer adsorbed onto the bonded-phase and the water-enriched interface) increase. However, at high water concentrations, where the column works in RPLC mode, the mobile phase volume increases and the stationary phase (which is now the bonded zwitterion) volume decreases when increasing the water percentage in the mobile phase.

Solubility of Benzanilide Crystals in Organic Solvents

The solubility of benzanilide in sixteen pure organic solvents, including N, N-dimethylformamide, tetrahydrofuran, butanone, acetone, ethyl acetate, dichloromethane, n-butanol, diethyl ether, n-pro...

A Methodology for the Estimation and Modelling of the Obstruction Factor in the Expression for Mesopore Diffusion in Reversed-Phase Liquid Chromatography Particles

An experimental methodology for the determination of the obstruction factor in the expression for mesopore diffusion in Zorbax Eclipse Plus C18 reversed-phase particles is proposed. The method uses peak parking experiments conducted on particles that were previously stripped of their stationary phase by flushing the column with trifluoroacetic acid at a temperature of 60°C. Further using pure organic solvents as the mobile phase, any potential retention or surface diffusion effect is omitted. To avoid interference between the parked peaks and baseline disturbances typically occurring when switching on and off the flow, peak parking experiments were carried out in a set-up wherein two identical columns were used in parallel. This set-up allowed to maintain the flow through the detector at all times, by redirecting the flow from one column to the other during the peak parking experiments. Several tracer molecules (ionic and deuterated tracers) were compared and it was found that the use of deuterated molecules provides the best possible coverage of the accessible space of the mesopore volume. Interpreting the peak parking responses obtained with these tracers with a model based on the effective medium theory (EMT) subsequently provided an estimate of the value of the mesopore diffusion obstruction factor γmp. Taking the well-established pore hindrance factor F(λ) correction into account, the obtained experimental γmp-values are more in agreement with the tortuous and constricted diffusion paths one can expect in the void space within a structure resembling a monolithic skeleton with tetrahedral connectivity rather than in the void space formed by a packing of nanospheres. This is also more in line with the measured internal porosity values lying around εpz=0.5, whereas a packing of nanospheres would rather correspond to an εpz of 0.4. As such, the presented protocol provides a means to infer the internal mesopore structure of reversed-phase particles.