Ammonium Acetate In Ethanol Research Articles

Protic Ionic Liquids as Electrolytes for Metal-Hydride Batteries

Nowadays, the most popular and effective energy storage systems are Li-ion batteries, despite some limitations such as high cost, flammability, temperature restrictions, and use of critical raw material (e.g. Co) [1]. This raises the challenge of the demand for alternative systems. One potential alternative is the Ni-MH battery, which are recognized for their good cyclability, competitive energy density, low memory effect, wide range of operating temperatures, low cost, and environmental friendliness [1]. Their practical use, however, is constrained due to their low specific energy density, high self-discharge rate, and electrode ageing [2,3].This work is focused on the study of the negative electrode of the Ni-MH battery and its interaction with the electrolyte. The objective aims to improve the performance of the negative electrode of Ni-MH batteries by substituting the conventional water-based KOH 8.7 M electrolyte by a Protic Ionic Liquid (PIL) to overcome aforementioned drawbacks [4]. PILs can exchange a labile proton, thereby supporting the main redox reaction, hydrogenation, at the negative electrode of Ni-MH battery.Thus, a series of twelve PILs or their combinations were synthesized and tested in a half-cell configuration. The charge/discharge cycle tests were carried out. Results showed that Pyrrolidinium Acetate (PyrrAc), Ethanolammonium Acetate (EOAAc) mixed with g-butyrolactone (GBL), and Diethanolammonium Acetate (DEOAAc) exhibited promising performance in half-cell configuration (Table 1).PyrrAc was shown to be an optimal electrolyte and has been further studied in terms of long-term performance and system degradation. The morphology of the aged negative electrodes was observed by Scanning Electron Microscopy (SEM) (Fig. 1). For instance, after 7 cycles of charge/discharge, formation of cracks was observed in the electrode (Fig. 1 (right)) due to hydrogen ab/desorption.The utilization of PyrrAc as electrolyte resulted in no initial capacity loss and, moreover, exhibited an increase in capacity during the first cycles, which can be recognized as an activation of the electrode (similar to the one observed in aqueous electrolytes). In order to obtain a complete understanding of the electrode stability, the electrolytes after cycling as well as calendar corrosion were studied using Inductively Coupled Plasma - Optical Emission Spectrometry (ICP-OES).[1] M.A. Hannan, M.M. Hoque, A. Mohamed, and A. Ayob, Renewable and Sustainable Energy Reviews, 69 (2017) 771–789.[2] B. Puga et al., ChemElectroChem, 2 (2015) 1321–1330.[3] J. Matsuda, Y. Nakamura, E. Akiba, J Alloys Compd, 509 (2011) 7498–7503.[4] T. Meng, K. H. Young, D. F. Wong, and J. Nei, Batteries, 3 (2017) 4. Figure 1

Studies on wetting behaviour of pure and aqueous protic ionic liquids (PIL) solutions on different surfaces: ILphobicity to ILphilicity

In this study, the wetting behaviour of pure protic ionic liquids (PILs) and their mixture with water was studied at ambient conditions. Ethanolammonium acetate [EAAc], ethanolammonium butyrate [EABu], and ethanolammonium hexanoate [EAHx] were used as PILs for the wetting studies on various surfaces. The contact angle and wetting area of pure and mixed PIL solutions were determined on superhydrophobic, hydrophilic, and total wetting surfaces. Smaller alkyl chain PIL, ethanolammonium acetate (EAAc) displayed the highest contact angle (CA) of 141° on superhydrophobic surfaces. On hydrophilic polycarbonate (PC), shorter anionic chain PILs demonstrated CA < 90°, showing the ILphilic behaviour, and the variation of CA was PIL anionic chain length dependent. Total wetting glass exhibited the lowest CA for [EAAc], which increased with the PIL anionic chain. A binary mixture of PIL with water demonstrated unique wetting behaviour on the total wetting surface. The aqueous drops of EAHx exhibited a dynamic contact line on the glass surface, showing the greatest expansion in wetting area compared to drops of aqueous EAAc or aqueous EABu. This occurrence could be ascribed to the substantial decrease in water surface tension induced by the hydrophobic hexanoate anion, potentially leading to improved spreading characteristics.

Thermal Stability of Protic Ionic Liquids.

While protic ionic liquids (ILs) have found great success as solvents for a broad range of applications, little is known about their degradation when exposed to temperatures above ambient for extended periods of time. Here, we report the thermal stability of six protic ILs, namely, ethylammonium nitrate, ethylammonium formate, ethylammonium acetate, ethanolammonium nitrate, ethanolammonium formate, and ethanolammonium acetate. The effect of heating each ionic liquid to 60 °C for 1 h or 1 week (sealed or open to the atmosphere) was evaluated by considering the changes to water content, pH, mass, thermal phase transitions, and molecular structure after each treatment. Heating each of the six ILs when sealed led to measurable shifts in their water content and 10 wt % pH, but there was no significant change in their mass, thermal phase transitions according to differential scanning calorimetry (DSC), or molecular structure using proton nuclear magnetic resonance (1H NMR) spectra, indicating that the samples were largely unchanged. The samples that were heated open to the atmosphere also displayed no significant changes after 1 h but displayed significant changes after 1 week.

Lyotropic liquid crystal phases of monoolein in protic ionic liquids.

Monoolein-based liquid crystal phases are established media that are researched for various biological applications, including drug delivery. While water is the most common solvent for self-assembly, some ionic liquids (ILs) can support lipidic self-assembly. However, currently, there is limited knowledge of IL-lipid phase behavior in ILs. In this study, the lyotropic liquid crystal phase behavior of monoolein was investigated in six protic ILs known to support amphiphile self-assembly, namely ethylammonium nitrate, ethanolammonium nitrate, ethylammonium formate, ethanolammonium formate, ethylammonium acetate, and ethanolammonium acetate. These ILs were selected to identify specific ion effects on monoolein self-assembly, specifically increasing the alkyl chain length of the cation or anion, the presence of a hydroxyl group in the cation, and varying the anion. The lyotropic liquid crystal phases with 20-80 wt. % of monoolein were characterized over a temperature range from 25 to 65 °C using synchrotron small angle x-ray scattering and cross-polarized optical microscopy. These results were used to construct partial phase diagrams of monoolein in each of the six protic ILs, with inverse hexagonal, bicontinuous cubic, and lamellar phases observed. Protic ILs containing the ethylammonium cation led to monoolein forming lamellar and bicontinuous cubic phases, while those containing the ethanolammonium cation formed inverse hexagonal and bicontinuous cubic phases. Protic ILs containing formate and acetate anions favored bicontinuous cubic phases across a broader range of protic IL concentrations than those containing the nitrate anion.

Synthesis, Characterization and Antibacterial Screening of Amino Cyanopyridines Analogues

The new series of amino cyanopyridine derivatives were prepared from mixture of Chalcones (2.3a-i), malononitrile and ammonium acetate in ethanol. all the newly synthesized compounds were evaluated for their antibacterial action in vitro against gram +ve bacteria S. aureus, B. subtilis and gram -ve bacteria P. aeruginosa, E. coli by agar well diffusion method. The tested compounds 3.1a showed good activity against two bacterial strain viz. E. coli, P. aeruginosa and the compound 3.1b showed good antibacterial activity against all bacterial strain w.r.t penicillin as a std. drig while remaining compounds showed moderate to poor activity. The chemical structures of the compounds were proved by IR, 1H NMR, Mass, C13 NMR spectrometric data.

Caffeine-protic ionic liquid interactions in aqueous solutions evaluated by volumetric and spectroscopic studies

A comprehensive study on volumetric and spectroscopic properties of ternary solutions [water + protic ionic liquids (PILs) + caffeine (CAF)] was performed. Volumetric and compressibility properties were evaluated at different concentrations and temperatures, by measuring density and speed of sound of solutions. The newly synthesized PILs, ethanolammonium acetate; [EAAc] and ethanolammonium hexanoate; [EAHx] was used as co-solute. The density and speed of sound have been estimated at four different temperatures (298.15 K to 313.15 K) and at 0.1 MPa. Using these experimental data, apparent molar-volume, -isentropic compressibility, volumes of transfer were evaluated to understand the solute–solute, solute–solvent and solute–cosolute interactions occurring within the ternary solutions. At lower concentrations, negative transfer volumes indicate the presence of hydrophobic interactions among components of PILs (cations/anions) and CAF. The transfer volumes become positive as the concentration of PILs rises, implying that hydrophilic interactions were strengthened. In addition, UV–visible spectroscopic analysis was also performed to evaluate the nature of interactions. Hydrogen bonding interactions were also suggested based on the hyperchromic shift observed in UV absorption when aqueous CAF was titrated with PILs solutions. Physico-chemical analysis of the PILs-caffeine system are essential for comprehending the kinds of interactions that may occur in liquid combinations used for therapeutic drug delivery.

The tannic acid–based iron nanoparticle: A capable nanocatalyst for the green synthesis of polyhydroquinolines

The tannic acid–based iron nanoparticle (TAN-Fe-NP) was prepared by a redox reaction between tannic acid and FeCl3 in water and characterized by the Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, energy dispersive X-ray analysis, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy techniques. Then, a TAN-Fe-NP nanocatalyst was used as an efficient catalyst for the synthesis of polyhydroquinolines from the reaction of ethyl acetoacetate, benzaldehydes, dimedone, and ammonium acetate in ethanol at 60 °C in high yields and low reaction times. Since this catalyst is made of natural materials, it has a great advantage compared with the other catalysts and is cheap, available, natural, safe, nontoxic, and eco-friendly as well.

Ammonium Acetate Catalyzed Formation of 1,5‐Benzodiazepines through [4+2+1] Cycloaddition Involving 5‐Hydroxymethylfurfural

AbstractThe use of the renewable platform molecule 5‐hydroxymethylfurfural (5‐HMF) in multi‐component reaction with a diamine and an alkynone to generate seven‐membered 1,5‐benzodiazepines is described. Due to the sensitivity of 5‐HMF to strong acidic and basic conditions, the investigation required an in‐depth revisit of reaction parameters as compared to benchmark aldehydes. Among catalysts/solvents couples, ammonium acetate in ethanol proved to be a clean and efficient system. These optimized conditions were subsequently used to investigate the scope of the reaction providing a library of 1,5‐benzodiazepines in moderate to good yields from a wide range of diversely substituted diamines and alkynones or alkyl alkynoates.

3,5-Bis(trifluoromethyl) phenylammonium triflate: a new and green organocatalyst for the synthesis of indeno[1,2?b]pyridines

3,5-Bis(trifluoromethyl) phenyl ammonium triflate(BFPAT) catalyzed one-pot synthesis of indeno[1,2-b]pyridine compound derivatives by four-component condensation of aldehyde, aromatic ketones, 1,3-indanedione, and ammonium acetate in ethanol. Accessible starting materials, Simplicity of operation, green and practical catalyst, easy purification, and excellent yields are the key benefits of the current technique.

One-Pot Synthesis of 1,8-Dioxodecahydroacridines using Ag-TiO2 Nanocomposite as a Mild and Heterogeneous Catalytic System

Abstract:Ag-TiO2 nanocomposite is reported to be an efficient, active, and benign recyclable catalyst for highly efficient synthesis of 1,8-dioxodecahydroacridine derivatives from dimedone, aromatic aldehydes, and several anilines or ammonium acetate in ethanol as a solvent at room temperature in a short reaction time and suitable yield. This catalyst is effortlessly recycled by simple filtration and can be reused up to five times with only a negligible loss in its catalytic effectiveness. Low catalyst loading, cost-effectively mild conditions, non-chromatographic purification of target compounds, excellent atom economy, informal procedure, use of a cheaply accessible nanocomposite catalyst, and recyclability of the catalyst are all significant benefits of this method. AFM analysis is performed to confirm the structure, topography, and morphology of Ag-TiO2 nanocomposite. 1,8-dioxodecahydroacridine derivatives having natural significance possess a wide range of pharmacological activities; for instance, antibacterial, antimalarial, anticancer, and mutagenic properties. In terms of the distinctions between aldehydes and anilines, this approach offers a wide range of applications.

Synthesis, spectroscopic characterization and apparent molar properties of ethanolammonium based ionic liquids with DMSO

The density (ρ) and speed of sound (u) of binary solutions containing protic ionic liquids such as N‑butyl ethanolammonium acetate [NBEA][Ace] and N‑butyl ethanolammonium propionate [NBEA][Pro] with Dimethyl Sulfoxide (DMSO) were determined over a temperature range of (293.15 to 318.15) K at intervals of 5 K at 0.1 MPa pressure. The apparent molar volume (Vφ), isentropic compressibility (ks) and apparent molar isentropic compressibility (ks,φ) were estimated using the measured data. The apparent molar volume (Vφ∞) and apparent molar isentropic compressibility (kφ∞) at infinite dilution, as well as the related empirical parameters (Sv, Bv, Sk and Bk), were calculated using the Redlich-Mayer type equation. The solute-solute and solute-solvent interactions are indicated by the obtained limiting apparent molar volume and limiting apparent molar isentropic compressibility. Furthermore, the apparent molar expansibility at infinite dilution was calculated using temperature dependent apparent molar volume at infinite dilution (Eφ∞).

Pretreatment of Jerusalem artichoke stalk using hydroxylammonium ionic liquids and their influences on 2,3-butanediol fermentation by Bacillus subtilis

Pretreatment of lignocellulose is a vital step for biological production of bio-chemicals and bio-fuels. In this work, the pretreatment of Jerusalem artichoke stalk (JAS) by hydroxylammonium ionic liquids was evaluated based on pretreatment efficiency including polysaccharide recovery and enzymatic digestibility, and influence of ionic liquids on 2,3-butanediol fermentation using Bacillus subtilis. The results showed ethanolammonium acetate (EOAA) was efficient in JAS pretreatment, and maximum cell density was increased 25% when EOAA concentration was not greater than 0.3 mol/L in medium, while the total concentration of acetoin and 2,3-butanediol was 15% greater than the control at 0.1 mol/L EOAA. After the pretreatment under optimized conditions of 170 °C for 5-h and liquid–solid ratio of 18, about 87% cellulose and 75% hemicellulose were recovered, and glucose yield of 64% and xylose of 66% were obtained after 24-h hydrolysis of JAS residue by cellulase (15 FPU/g) with solid loading of 10 wt%.

Lignin extraction from black liquor using acetate based ionic liquids: Extraction kinetics and product characterization

One ionic liquid, 1-ethyl-3-methylimidazolium acetate [Emim][Ac] and four acetate-protic ionic liquids (PILs), ethanolammonium acetate [Eth][Ac], diethylenammonium acetate [DiEt][Ac], propylammonium acetate [Prop][Ac], and pyrrolidinium acetate [Pyrr][Ac], were employed to extract lignin from Kraft black liquor (BL). Under atmospheric pressure and at 368 K, the total lignin extracted was 75.3 ± 3.4% (wt%) when using [Eth][Ac] in a 20:1 (w/w) [Eth][Ac]:BL ratio and a reaction time of 270 min. Fourier transform infrared (FTIR) spectroscopy and proton nuclear magnetic resonance (1H NMR) were employed to characterize the extracted lignin. Gel permeation chromatography revealed that molecular weights of 2283±67 g mol−1 and 1892±122 g mol−1 were measured for the lignin extracted using [Eth][Ac] and [Prop][Ac], respectively. The kinetics of lignin extraction were examined for a 270 min. reaction time period at three different temperatures. The lowest activation energy (Ea = 6.5 kJ·mol−1) was affiliated with [Prop][Ac]. The PIL with the maximum total lignin extracted, [Eth][Ac], was regenerated using vacuum distillation, and the lignin extraction ability of the regenerated solvent was found to be equivalent to the fresh solvent.

Density, speed of sound, and surface tension of binary aqueous solutions containing ammonium based protic ionic liquids

Density, ρ, speed of sound, u, and surface tension γ, of binary mixtures containing ethanolammonium based protic ionic liquids (PILs) and water were measured to access the influence of PIL-water interactions on physicochemical properties. Volumetric properties of PILs were evaluated at ambient pressure but at temperatures from 298.15 K to 313.15 K. Apparent molar volume and apparent molar isentropic compressibility values of ethanolammonium acetate [EAAc], ethanolammonium butanoate [EABu], and ethanolammonium hexanoate [EAHx], were calculated and commuted to determine the infinite dilution partial molar volume using Redlich-Mayer type of equation. Further, excess molar volume was also determined as a function of mole fraction. The coefficients of Redlich-Kister equation also determined and presented. Overall, the hydrophilic interactions occur between PILs and water molecules and the strength of interactions weakens as anionic chain length increases. Low surface tension values were observed for PILs with longest alkyl chain. The results indicate that hydrophobicity of alkyl chain strongly influences the interfacial properties.

P-TSA Catalyzed Synthesis of Tetrahydrobenzo[g]quinolines via Multicomponent Reaction using Pyrazole Aldehyde, Lawsone, β-Ketoesters and Ammonium Acetate

An efficient protocol has been developed for the multicomponent synthesis of tetrahydrobenzo[g]quinoline-3-carboxylate derivatives using p-toluenesulfonic acid (p-TSA) as catalyst through one-pot four component condensation reaction of pyrazole aldehyde, Lawsone, β-ketoesters and ammonium acetate in ethanol. The synthesized compounds were characterized by spectroscopic techniques.

Green chemistry approach for the synthesis of 2,4,5-triaryl-1H-imidazole derivatives using lemon juice as a bio-catalyst

The use of green chemistry is crucial for organic synthesis to protect the environment from hazardous and toxic substances. Lemon juice is a promising candidate for a green chemistry catalyst because it is widely available, inexpensive, biodegradable, and non-toxic. This study reports a simple and highly effective one-pot synthesis of 2,4,5-triaryl-1H-imidazole derivatives 4(a-l) using lemon juice as a biocatalyst. The method involves a three-component condensation reaction of benzil, aromatic aldehydes, and ammonium acetate in ethanol using lemon juice asa catalyst, and offers several benefits such as short reaction time, easy work-up, low-cost catalyst, and good yields. Additionally, in silico prediction of ADME properties suggests that the synthesized compounds 4(a-l) have the potential to exhibit favourable oral drug-like properties.

One-Pot Synthesis of 2,4,5-Triaryl-1H-imidazoles Using Glutamic Acid as Catalyst

Glutamic acid has been found to be an efficient organocatalyst for one-pot synthesis of 2,4,5-triaryl substituted imidazole by using a mixture of an aromatic aldehyde, a benzil or benzoin and an ammonium acetate in ethanol as solvent. The cleaner reaction, and easy workup make this protocol practical and economically attractive. DOI: http://dx.doi.org/10.17807/orbital.v13i3.1611

Eco-Friendly Chromatographic Methods for Determination of Acemetacin and Indomethacin; Greenness Profile Assessment.

The green chemistry approach was developed for the purpose of saving the environment by using green solvents. Applying green analytical chemistry principles to traditional methods is considered a challenge. Acemetacin is a commonly used analgesic prodrug that bioactivates to indomethacin. Developing two simple, eco-friendly chromatographic methods for simultaneous determination of acemetacin and indomethacin. The first method is HPLC-DAD. Separation was performed on a Waters XBridge® Shield RP18 (250 × 4.6 mm, 5 µm) analytical column with ethanol-ammonium acetate buffer (50 mM, pH 3.5 ± 0.1; 60:40, v/v) as a mobile phase at a flow rate of 1 mL/min at 25 ± 0.5°C and UV detection at 254 nm. The other method is TLC coupled with densitometric quantification using pre-coated silica TLC plates and butanol-ethyl acetate (70:30, v/v) elution system. The plates were scanned at 254 nm. Both methods were validated according to International Conference on Harmonization guidelines. Linearity was confirmed for both over a concentration range of 1-100 µg/mL for the HPLC method and 0.2-7 µg/band for TLC-densitometric method. The methods' greenness was evaluated by the National Environmental Methods Index, Eco-Scale, Green Analytical Procedure Index metrics and Analytical GREEnness Metric Approach. The proposed methods were found to be suitable for determination of studied drugs in their marketed formulations and is suggested for routine analysis in quality control laboratories. The developed HPLC method shortened the elution time of the analyzed drugs saving more time and money and the TLC method lowered the drugs' detection limit. HPLC and TLC methods were validated for the assay of acemetacin and indomethacin. The methods' greenness was evaluated and compared to published methods. The developed HPLC method shortened the elution time of the analyzed drugs, saving time and money and the TLC method lowered the drugs' detection limit.

An eco-friendly synthesis of polyhydroquinoline derivatives using MoO3 promoted CeO2-ZrO2 solid heterogeneous catalyst

The molybdenum (8–20 wt%) (MoO3) promoted CeO2-ZrO2 (ceria-zirconia) solid solutions were prepared using precipitation and impregnation method, calcined at 500 °C. The catalytic potency of synthesized materials were tested for the synthesis of polyhydroquinoline derivatives using a mixture of various aromatic aldehydes, dimedone, and ethyl acetoacetate and ammonium acetate in ethanol under reflux condition. Amazingly, it was observed that with increasing Mo wt% loading increases the excellent yield of product this may be due to acidic nature of MoO3. Particularly, the 20 wt% MoO3 promoted CeO2-ZrO2 catalyst exhibited promising catalytic activity in terms of excellent yield of the products with short reaction time. The present methods significantly contributed as efficient and eco-friendly method for the synthesis of polyhydroquinoline derivatives.

Development of an efficient, one-pot, multicomponent protocol for synthesis of 8-hydroxy-4-phenyl-1,2-dihydroquinoline derivatives.

A one‐pot quick and efficient multicomponent reaction has been developed for the synthesis of a new series of functionalized 8‐hydroxy‐4‐phenyl‐1,2‐dihydroquinoline derivatives using 30 mol% ammonium acetate in ethanol as solvent. This economical protocol run smoothly to give variety of quinoline derivatives in 55% to 98% yield from inexpensive reagents and catalyst in mild reaction conditions. Various spectroscopic techniques like FTIR, 1H NMR and 13C NMR, MALDI‐TOF‐MS, and EI‐MS were used to study and confirm their structure.