Tetraethylammonium P-toluenesulfonate Research Articles

Fitting of experimental viscosity to temperature data for deep eutectic solvents

Seven new deep eutectic solvents (DESs) based on tetrabutylammonium bromide (TBAB) and tetraethylammonium p-toluene sulfonate (TEAPTS) were prepared and their viscosity determined between 298.15 and 323.15 K. The effect of temperature was modeled using an appropriate fitting procedure, proposed in this work, with a coefficient of determination R2 > 0.99 for all DES. The fitting procedure used of pre-existing experimental data in which 70 DESs were collected from the literature and refined on the basis of R2 and root mean square error (RMSE); ~10% of the data was rejected. Furthermore, about half of the refined data was fitted with a three-parameter Vogel–Fulcher–Tammann (VFT) equation with an R2 higher than 0.99. The remaining data were more adequately fitted with a two-parameter Arrhenius equation. The adjusted parameters of both models for 62 DESs were determined to estimate the viscosity. Based on R2, the VFT model was more accurate than the Arrhenius model. Moreover, additional in-lab experiments were performed for model validation at six temperatures (from 298.15 to 323.15 K). In some cases, the experimental measurements were different from those in the literature with an R2 below 0.95 indicating a large scatter in the viscosity data. Most of the highly viscous DESs considered in this study showed a rapid decay when temperature increases. Hence, the limitation of using these solvents for applications such as absorption could be overcome by operating at slightly higher temperature (i.e., 313.15 to 333.15 K).

Modifying Mesoporous TiO2 by Ammonium Sulfonate Boosts Performance of Perovskite Solar Cells

Mesoporous-structure perovskite solar cells (meso-PVKSCs) have been widely utilized due to the achieved high efficiency for which the TiO2 layer usually suffers from sufficient electron trap states, low electron mobility, and inavoidable catalytic activity. Herein, a mesoporous TiO2 (m-TiO2) layer is modified by tetraethylammonium p-toluenesulfonate (abbreviated as TEATS) for the first time, leading to a significant photoelectric conversion efficiency enhancement from 19.14 to 20.69% for Cs0.05MA0.12FA0.83PbI2.55Br0.45 (abbreviated as CsMAFA) meso-PVKSCs. In particular, the obtained champion open-circuit voltage (Voc) is 1.18 V, which is a record high value for meso-PVKSCs with CsMAFA triple cation mixed perovskite. A series of measurements were employed to investigate the influences of TEATS modification on the energy band structures of TiO2 as well as the CsMAFA perovskite layer atop, unveiling that TEATS modification benefits defect passivation of the TiO2 film along with a decrease in the work function of TiO2. Besides, TEATS modification helps to improve the wettability of perovskite precursors on the m-TiO2 substrate, affording improved film quality of perovskite with enhanced crystallinity and grain size. Consequently, the trap states existed in the perovskite film can be passivated, and the interfacial charge recombination is suppressed. This further benefits the improvement of the ambient stability of devices.

SFG Study of the Potential-Dependent Adsorption of the p-Toluenesulfonate Anion at an Activated Carbon/Propylene Carbonate Interface

Sum frequency generation spectroscopy has been used to characterize the potential-dependent adsorption of the p-toluenesulfonate anion at the activated carbon/propylene carbonate interface of the commercial carbon YP50F. Spectra recorded from the interface between YP50F and a 1 M tetraethylammonium p-toluenesulfonate in propylene carbonate solution showed no ordered anion adsorption without an applied potential. In contrast, there is clear evidence of increasingly ordered anion adsorption with applied potential. Furthermore, there is evidence of hysteresis such that the anion remains adsorbed when the applied potential was decreased back to 0 V. Significant reversal of polarity was required before the anion signal was lost. Changes to the propylene carbonate solvent peaks during the electrochemical cycle were also observed. The data indicate that the positive electrode charges either via a counterion adsorption mechanism or via an ion-exchange mechanism.

Electrothermal Feedback in Polypyrrole Coated Cotton Fabric

In this study, polypyrrole (PPy) was coated by chemical oxidation through in-situ polymerization technique. Tetraethyl ammonium p-toluene sulfonate (TEAp-TS) was chosen as a doping agent along with FeCl3 as oxidizing agent. Six different fabric samples were prepared by varying concentrations of monomer, doping agent and oxidizing agent in order to obtain samples with different electrical resistivity. Each sample was exposed to four different temperatures (80, 120, 160 and 200 °C) and electrical resistivity was recorded at different intervals in the range 0-600 seconds. In this way the influence of temperature on electrical resistivity of PPy coated cotton fabric samples was analyzed and found that resistivity decreases with the increase in temperature in two minutes significantly. FT-IR spectrum confirms that there is no change in PPy before and after heating of samples. SEM micrographs showed the deposition of PPy on cotton fibers surface.

Coordination ability of alkali metal or alkaline earth metal ions with aromatic dicarboxylate, sulfonate, or disulfonate ions in acetonitrile

In a poor solvating solvent, acetonitrile, the coordination ability of alkali metal (Li+, Na+) and alkaline earth metal (Mg2+, Ca2+, Ba2+) ions with carboxylate and sulfonate ions has been thoroughly examined, based on the precipitation of non-charged species and the successive re-dissolution of charged species. At first, the formation of [C6H5CO2Ca]+ (the calcium benzoate cation) in acetonitrile was evidenced by ESI-MS. Tetraethylammonium 3-nitrophthalate (3-nitro-1,2-benzenedicarboxylate, L2−) of 2.0×10−3moldm−3 was precipitated completely by the addition of 2.0×10−3moldm−3 Ca(ClO4)2, although the absorption spectrum of L2− was only slightly changed by 1.0×10−3moldm−3 Ca(ClO4)2. In the presence of 5.0×10−3moldm−3 Ca(ClO4)2, however, the precipitates re-dissolved drastically. The successively formed species between Ca2+ and L2− were proposed to be CaL22−, CaL0, and Ca2L2+. The lithium ion also caused the precipitation of non-charged species (Li2L0) as well as the re-dissolution of charged species (tentatively assigned to be Li3L+ or Li4L2+), however, the re-dissolution with Na+ took place just hardly. We were able to observe the re-dissolution of precipitates for 4-nitrophthalate through the formation of positively charged species in the presence of excess amounts of the alkaline earth metal ions, but not of the alkali metal ions. Tetraethylammonium p-toluenesulfonate, and 1,5-, 2,6-, and 2,7-naphtalenesulfonates were also examined. The “reverse” coordination constants have been successfully evaluated for some of all the systems, e.g., K2=3×107 (2 Mg2++L2− ⇆ Mg2L2+) and K3=2×108 (3 Li++L2− ⇆ M3L+), where L2−=2,7-naphthalenedisulfonate.

Novel potentiometric sensing of creatinine

The potentiometric sensing device for quantitative estimation of creatinine is reported. The sensor comprises a bi-enzymatic reactor and potentiometric urea biosensor. The bi-enzymatic reactor is developed by sandwiching two enzymes, creatininase and creatinase, within two layers of organically modified sol–gel glass (ORMOSIL). The urea biosensor is developed by immobilizing urease on a new pH sensor developed by p-toluenesulfonate doped polyaniline-modified electrode. The polyaniline-modified electrode is developed by potentiodynamic electropolymerization of aniline based on sweeping the electrode potential within −0.7 to 2.0 V versus Ag/AgCl in non-aqueous medium in the presence of tetraethylammonium p-toluenesulfonate as supporting electrolyte. The enzyme reactor converts creatinine into urea. The urea formed through bienzymatic reactor is monitored by new urea biosensor. The typical results on urea sensing, pH sensing and creatinine sensing are reported. The detection limit of the new sensor for urea is 5 μM and for creatinine is 100 μM.

Electrochemical Formation of Methoxy‐ and Cyano(phenylazo)alkanes from Aldehyde and Ketone Phenylhydrazones.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Preparation and properties of polypyrrole

Optimal conditions and improvement methods for electrochemical polymerization of pyrrole (Py) in the presence of sodium p-toluenesulfonate (PTS) as a dopant in water were studied. The electrical and spectral properties of poly-Py (PPy) doped with PTS were compared with those of PPy doped with sodium alkylbenzenesulfonates such as sodium benzenesulfonate (BS), sodium 4-ethylbenzenesulfonate (EBS), sodium 4-n-octylbenzenesulfonate (OBS), sodium dodecylbenzenesulfonate (DBS) and tetraethylammonium p-toluenesulfonate (Et 4 NPTS), prepared under the same polymerization conditions. UV-Vis-NIR absorption spectra were independent of the electrolytes used.

Ionic Conductivity in Binary Solvent Mixtures. 6. Behavior of Selected 1:1 Electrolytes in 80 mass Propylene Carbonate + p-Xylene at 25 °C

The electrolytic conductance behavior of certain univalent electrolytes, viz., tetrabutylammonium tetraphenylborate, tetrabutylammonium halides, tetrabutylammonium perchlorate, tetraethylammonium perchlorate, tetraethylammonium iodide, tetraethylammonium 2,5-dichlorobenzenesulfonate, tetraethylammonium p-toluenesulfonate, tetramethylammonium iodide, sodium tetraphenylborate, sodium iodide, and potassium iodide in 80 mass % propylene carbonate + p-xylene, was studied. The conductance data were analyzed by the Fuoss conductance−concentration equation. The ionic conductivities have been calculated using the Λ0 value of tetrabutylammonium tetraphenylborate as a reference value that is independent of solvent. The association constants and cosphere diameters for the above electrolytes are reported. The variations of ionic conductivities are explained in terms of viscosity, the Stokes radii in some specific cases, and specific ion−solvent interactions.

Electrochemical Formation of Methoxy- and Cyano(phenylazo)alkanes from Aldehyde and Ketone Phenylhydrazones

Several aldehyde and ketone phenylhydrazones were electrooxidized in MeOH. Electrooxidation in the presence of KI or tetraethylammonium p-toluenesulfonate as the supporting electrolyte afforded the corresponding methoxy(phenylazo)alkanes. whereas electrooxidation in the presence of KI, NaCN, and HOAc afforded the cyano(phenylazo)alkanes.

Characteristics of electrochromic device with polypyrrole and WO 3

The characteristics of electrochromic films (WO3, V2O5) prepared by sol-gel-spin coating and a vacuum evaporation process were compared to identify a new application of an electrochromic display. Polypyrrole films were prepared by electropolymerization in a pyrrole solution, acetonitrile, and TEPS (tetraethylammonium p-toluenesulfonate). The liquid electrolyte was prepared using LiClO4, propylene carbonate, polymethylmetacrylate, and ethyl acetate. The optical modulation of the electrochromic device was measured as the LiClO4: PMMA weight ratio changed from 10:3 to 10:5. The highest optical modulation value was when the LiClO4: PMMA weight ratio was 10:4. Each type of film was analyzed using a four-point probe, a differential scanning calorimeter (DSC), an X-ray diffractometer (XRD), and a UV-vis spectrophotometer (DR/4000H). The ESCA spectra of the WO3 films showed that the tungsten oxidation number decreased in a coloration state. © 2001 Kluwer Academic Publishers

In situ EPR/UV–VIS spectroelectrochemistry of polypyrrole redox cycling

The redox behaviour of polypyrrole layers prepared by the electrochemical oxidation of pyrrole in acetonitrile solutions was studied using insitu EPR/UV–VIS spectroelectrochemistry. Various supporting electrolytes: p-toluene sulfonic acid, tetrabutylammonium perchlorate (TBAP) and tetraethylammonium p-toluene sulfonate (TEATos), were used. Optically transparent indium tin oxide (ITO)-coated glass and gold mesh electrodes were used as electrode materials. Using the calibrated manganese EPR standard, the quantitative time dependences of the three oxidation states in the polymer layer were obtained during redox cycling. The separation of the superimposed UV–VIS spectra was carried out by a least-squares method. The different mechanisms of the polymer oxidation, the polaron/bipolaron route and polaron/dimer route, are compared.

Nitrate ion‐selective sensor based on electrochemically prepared conducting polypyrrole films

AbstractNitrate‐doped polypyrrole (PPy) films on a glassy carbon substrate have been prepared electrochemically in aqueous, acetonitrile, and propylene carbonate solutions for use as nitrate sensors. Lithium nitrate, sodium nitrate, nitric acid, tetraethylammonium p‐toluene sulfonate (TS), and tetradodecylammonium nitrate (TDN) were employed as electrolytes. The effect of dibutylphthalate (DBP) as a plasticizer on the sensitivity and lifetime of PPy film sensors was also investigated. A Nernstian behavior with a slope of 56.9 m V/decade over 0.1–7.4 × 10−5 M NO and a detection limit of 4.7 × 10−5 M were observed for the polymer sensor prepared in acetonitrile solution containing lithium nitrate and 15% plasticizer (DBP). A lifetime of more than 6 months for this PPy film electrode was obtained.

Improved preparation of polybenzo[ c]thiophene-modified electrodes employing p-toluenesulfonate as dopant anion

Use of tetraethylammonium p-toluenesulfonate (TEATos) as electrolyte for electrodeposition of polybenzo[ c]thiophene from CH 3CN solution gives compact, smooth films on indium-doped tin oxide electrodes. These grow at lower overpotentials, and with fewer problems of film inhomogeneity, than films grown using tetrafluoroborate electrolytes. Films up to 10 μm thick have been deposited with TEATos, but film growth is self-limiting with tetraethylammonium tetrafluoroborate (TEAT). TEATos-grown films have a different morphology, but can still be reversibly p-doped in the same way as TEAT-grown films. n-Doping, however, is not electrochemically improved by using TEATos as growth electrolyte.

Silicon-controlled oxidation of enol acetates to enones by electrochemical method

Anodic oxidation of β-silylcycloalkanone enol acetates 1a-d in glacial acetic acid containing tetraethylammonium p-toluenesulfonate afforded α,β-unsaturated β-silylcycloalkenones 2a-d exclusively in 81–95% yields. The silyl group in 1a-d directed the oxidation under electrochemical conditions.

Electropolymrization and physicochemical properties of polypyrrole p‐toluenesulfonate

AbstractPolypyrrole p‐toluenesulfonate (PPTS) polymers were synthesized by the electrochemical technique from 0.2M pyrrole in 0:100, 1:99, 5:95, and 10:90 water/acetonitrile solutions containing 0.1M tetraethylammonium p‐toluene sulfonate (TEATS) as a supporting electrolyte. Following the cyclic voltammetry measurements, the number of electrons involved in the reaction was determined to be unity. The results of thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) showed that the weight loss was most reapid in the temperature range from 533 K to 768 K, and the maximum value of the reaction rate was 0.27 mg/min at 651 K. From the temperature dependence of the electrical condutivity and electron spin responance (ESR) measurement, a small pallaron hopping conduction was suggested for PPTS polymers. © 1994 John Wiley & Sons, Inc.

Chemical and physical properties of electrochemically prepared polyaniline p-toluenesulfonates

Polyaniline p-toluenesulfonate (PATS) was synthesized by the electrochemical technique from 0.2 M aniline in 1:99 water/acetonitrile solution containing 0.1 M tetraethylammonium p-toluenesulfonate (TEATS) as supporting electrolyte. Following the polarographic and cyclic voltammetry measurements, the values of the half-wave potential, transfer coefficient and number of electrons were measured to be 516 mV, 0.49, and 1, respectively. The results of TGA and DSC showed the the weight loss was most rapid in the temperature range from 553 to 653 K, and the maximum value of the reaction rate was 0.23 mg/min at 611 K. The electrical conductivity of PATS was measured in the temperature range from 123 to 298 K. From the plot of resistivity vs 1/T, E{sub a} was obtained to be 0.038 eV. From the temperature dependence of the conductivity and ESR measurements, it is suggested that the conduction mechanism for PATS is possibly a small polaron hopping conduction.

Electrically Conductive Polymer Composite from Polypyrrole and Electrodeposited Poly(p-phenylene terephthalamide) Film

Electrically conductive composites from polypyrrole (PPy) and poly(p-phenylene terephthalamide) (PPTA) were formed by electropolymerization of pyrrole on the electrode covered with PPTA film prepared by electrolysis of PPTA polyanions dissolved in dimethylsulfoxide. For the PPTA film annealed above 250°C, the polymerization of pyrrole hardly took place. Based on DSC measurements, it was found that the remaining solvent of PPTA film was closely related to composite formation. The morphologies of the composites varied, depending on the supporting electrolytes of tetraethylammonium p-toluenesulfonate and lithium perchlorate. The conductivity of the composite was 5–50 S cm−1. The composite showed improved mechanical properties: tensile strength was 142 MPa and tensile modulus was 6.2 GPa for the PPy(TsO−)/PPTA composite, where TsO− denotes the p-toluenesulfonate ion. The temperature dependence of the dynamic viscoelasticity of the PPy(TsO−)/PPTA composite was well explained by Takayanagi’s two-phase model, which was also consistent with SEM observation. The conductivities of the composites doped with p-toluenesulfonate and perchlorate were both retained at all times up to 150°C, whereas that of the pure PPy film decreased to 80% the original value after annealing at 150°C, being independent of the dopants. PPTA film was dimensionally stable and heat-resistant, and these properties provided a stable conductive composite film.

Electrochemical studies of sulfonates in non-aqueous solvents Part I. Polarographic reductions of alkali metal ions with sulfonate supporting electrolyte in N,N-dimethylformamide and acetonitrile

The effect of the supporting electrolytes tetraethylammonium p-toluenesulfonate, methanesulfonate and trifluoromethanesulfonate on the polarographic reduction of alkali metal ions in N,N-dimethylformamide and acetonitrile has been investigated. In tetraethylammonium trifluoromethanesulfonate supporting electrolyte, the polarographic reductions of alkali metal ions are almost the same as those in perchlorate in both solvents. In tetraethylammonium p-toluenesulfonate and methanesulfonate, the half-wave potentials shift to more negative potentials, especially in acetonitrile. These shifts can be explained in terms of ion-pair formation between the alkali metal ion and the supporting electrolyte anion.

Electrochemical studies of sulfonates in non-aqueous solvents: Part I. Polarographic reductions of alkali metal ions with sulfonate supporting electrolyte in N,N-dimethylformamide and acetonitrile

The effect of the supporting electrolytes tetraethylammonium p-toluenesulfonate, methanesulfonate and trifluoromethanesulfonate on the polarographic reduction of alkali metal ions in N,N-dimethylformamide and acetonitrile has been investigated. In tetraethylammonium trifluoromethanesulfonate supporting electrolyte, the polarographic reductions of alkali metal ions are almost the same as those in perchlorate in both solvents. In tetraethylammonium p-toluenesulfonate and methanesulfonate, the half-wave potentials shift to more negative potentials, especially in acetonitrile. These shifts can be explained in terms of ion-pair formation between the alkali metal ion and the supporting electrolyte anion.