Butyl Ammonium Research Articles

Luminescent Mannich bases: Synthesis, crystal structures, and photophysical properties

Three Mannich bases have been obtained starting from 5‑bromo-salicylaldehyde: 5‑bromo-3-(((2-(dimethylamino)ethyl)(methyl)amino)methyl)-2-hydroxybenzaldehyde (TMEN), 5‑bromo-3-((benzyl(methyl)amino)methyl)-2-hydroxybenzaldehyde (MBA), 5‑bromo-3-(ethyl(methyl)amino)methyl)-2-hydroxybenzaldehyde (EMA). The crystal structure of MBA has been solved. The UV–Vis absorption and emission spectra were investigated in different solvents, revealing the presence of several species, the neutral forms, the zwitterionic, the anionic and the cationic (the protonated nitrogen) ones. In order to characterize the last two species, further experiments were performed in the presence of hydrogen extracting and hydrogen donating compounds, sodium fluoride (NaF) and tetrabutylammonium hydroxide (TBOH) to evidence the anion, and trichloroacetic acid (TCA) for the protonated cation. The experimental results were rationalized by DFT calculations of the potential energy surfaces (PES) of the S0 and S1 states and of the absorption and emission maxima.

Unveiling the impact of organic cation passivation on structural and optoelectronic properties of two-dimensional perovskites thin films

Several organic cations have been used to passivate perovskite films; however, selecting the optimal cation remains challenging. In this work, we carried out density functional theory calculations to understand the effects induced by 17 different organic cations on the passivation (P-cations) of thin two-dimensional P2 (MAn−1)PbnI3n+1 perovskites films, where n=1 and 2. We found that the interactions between different types of P-cations and the inorganic slab affect the length and angles of the bonds within the inorganic framework (PbI6-octahedra). In general, the binding mechanism includes the interactions of organic cations with the inorganic framework, which leads to the accumulation of electron density within the halides, indicative of Brønsted–Lowry acid–base interactions. Oxygenated groups facilitate additional H-bond formation through -OH and -COOH groups, promoting the localization of the electron density between layers and improving the energetic stability of the system. Based on the results and analysis, we found that three P-cations might have higher potential for real-life applications, namely 4-fluorophenylethylammonium (FPEA), phenylethylammonium (PEA) and butylammonium (BtA).

Tetra Butyl Ammonium Bromide Catalyzed Synthesis of Thiols and Thioethers

A simple and commercially feasible route of synthesis of thiols and thioethers was developed using a simple phase transfer catalyst, i.e., Tetra Butyl Ammonium Bromide (TBAB). Sodium hydrogen sulfide (NaSH) is used as a sulfurization agent which is easily available and cost-effective. Thiols are obtained by treating alkyl or benzyl halides with sodium hydrogen sulfide (NaSH) in the presence of a phase transfer catalyst (TBAB) at 10 to 15℃. Thioethers are obtained by benzyl thiols treated with corresponding benzyl halides in the presence of a phase transfer catalyst (TBAB) at 10 to 15℃. Synthesis of thiols and thioethers is achieved by substitution reaction of benzyl or alkyl halides with sulfide in the presence of phase transfer catalyst (TBAB) and monochlorobenzene as a solvent at 10 to 15℃. Milder reaction conditions, excellent yield, shorter reaction time and operational simplicity are the key features of this procedure.

Synthesis and Characterization of Palladium Catalyzed (Carbon-carbon Bond Formation) compounds

In atmospheric condition, cesium carbonate was dissolved in water in a small bottle. Aryl halides, phenyl boronic acid, tetra butyl ammonium bromide, Bis (tri phenyl phosphine) palladium II chloride catalyst and toluene were taken in another small bottle. The contents of both the small bottles were added in a pressure tube. Heating of reaction mixture was done at 80-900C and then stirred until the reaction completion, which was confirmed by TLC. After this, the reaction mixture was extracted with ethyl acetate and the organic layer was washed with brine solution and then filtered by buckner funnel prepared with celite bed. Sodium sulphate was added to the filtrate, filtered again using cotton bed and silica (60-120 mesh size) was added to the filtrate and evaporated by using rotavapour. Through column chromatography, the crude product obtained was purified using Ethyl acetate/Hexane as mobile phase.Bis (tri phenyl phosphine) palladium II chloride catalyzes the reaction of aryl halides and phenyl boronic acid at 80-900C giving moderate to high yields even when the catalyst quantity used was low.

Simultaneous deep eutectic solvent based microextraction of Allura Red and Brilliant Blue in violet-purple foodstuffs

A vortex-assisted simultaneous deep eutectic solvent based microextraction and spectrophotometric determination method was established for the first time to simultaneously monitor Allura Red and Brilliant Blue in violet-purple foodstuffs. A ternary deep eutectic solvent was created using benzoic acid, tetra butyl ammonium bromide and benzyl alcohol at 1:1:3 mol ratio. The method variables including pH, volume of deep eutectic solvent and vortex time were optimized by Box-Behnken design of response surface methodology. The limits of detection were determined to be 25 and 9 µg/L for Allura Red and Brilliant Blue, respectively. The linear dynamic ranges of the method were obtained between 82 and 12,000 and 29–4200 µg/L for Allura Red and Brilliant Blue, respectively. Preconcentration factor of the method was obtained as 15. Greenness evaluation was performed using Analytical GREEnness tools. Extraction mechanisms affecting quantitative simultaneous microextraction of the target dyes were explained. The developed method was validated with high-performance liquid chromatography analysis. Analyte addition-recovery tests were also applied to confectionery samples to validate the proposed method and determine the dye contents of foodstuffs. Allura Red and Brilliant Blue contents of violet-purple confectioneries were determined between 3.85 and 74.59 and 4.02–26.11 µg/g concentrations with 94.5–98.6 % and 93.0–101.0 % recoveries, respectively.

Adsorption differences of xanthate, dithiophosphate and dithiocarbamate on stibnite (010) surface with Cu2+ activated: Combined DFT calculations and experiments

Antimony is an important strategic metal resource. Stibnite as one of the main sources of antimony resources, efficiently recycling stibnite has always been a topic of interest. Currently, there is a scarcity of research examining the adsorption differences of butyl xanthate (BX), sodium diethyldithiocarbamate (DDTC) and ammonium dibutyl dithiophosphate (ADD) on the stibnite (010) surface with Cu2+ activated based on atomic scale. This study investigates the adsorption differences of BX, DDTC and ADD on the stibnite (010) surface with Cu2+ activated, combining density functional theory with experiments. DFT calculations showed that there are five adsorption sites of Cu2+ on the stibnite surface, analysis of partial density of states (PDOS) indicated that the difference in hybridization strength between Cu 3d and S 3p orbitals caused discrepancy in adsorption sites performance. Analysis of PDOS, Mulliken population and electron density difference, it can be concluded that the collector interaction strongly with the stibnite surface with Cu2+ activated and the difference of charge transferred by S atoms during the interaction process is the main reason for the differences in adsorption performance and the varying stability of CuS bonds in adsorption models. Under comprehensive comparison the flotation experiments and adsorption tests showed that with Cu2+ activation, the recovery rate of stibnite was significantly improved with DDTC and the adsorption effect was optimal. Finally, the adsorption performance sequence on Cu2+ activated stibnite surface for the three collectors is as follows: DDTC > ADD > BX. This study combining experimental and DFT calculations, provides guidance for the development of efficient collectors for stibnite flotation in the future.

A smartphone-assisted sensing hydrogels based on UCNPs@SiO2-phenol red nanoprobes for detecting the pH of aquatic products

For some aquatic products, pH has been considered a useful index to reflect the changes in materials during the loss of freshness. Based on the inner filter effect (IFE) between deprotonated phenol red (PR) and upconversion nanoparticles (UCNPs), UCNPs coated with PR-doped SiO2 shell were embedded in agarose hydrogel to develop a smartphone-assisted method for pH sensing. With the enhancement of pH response using a phase transfer agent (i.e., tetra butyl ammonium hydroxide, TBAH), the proposed senor realized the colorimetric and fluorescence detection of pH in the range of pH 6.6–8 and pH 6–8, respectively. The sensor also showed satisfied reversibility when switched between pH 6 and 8 for at least 5 cycles. Moreover, this sensor displayed great sensitivity, stability, and portability in analyzing actual fish, shrimp, and shellfish samples, providing a new sight for evaluating the freshness of aquatic products.

The effect of organic ligand length on structural, vibrational and electrical properties of low-dimensional cobalt hybrid perovskites

Recently, two-dimensional hybrid organic–inorganic perovskites (2D-HOIPs) have emerged in popularity due to ease of tunability in terms of the structure and properties. However, a systematic chemistry and physical description of cobalt-based system is lacking. In this study, we employ X-ray diffraction, Raman spectroscopy and electrochemical impedance spectroscopy (EIS) techniques to investigate the effect of the organic ligand length on the structural, vibrational, and electrical properties of A2CoCl4 [A = methylammonium (MA), ethylammonium (EA) and butylammonium (BA)] perovskite. Results from the measurements showed a noticeable difference and showed potential usage in future applications in the field of electronics.

Boosting exciton mobility approaching Mott-Ioffe-Regel limit in Ruddlesden−Popper perovskites by anchoring the organic cation

Exciton transport in two-dimensional Ruddlesden−Popper perovskite plays a pivotal role for their optoelectronic performance. However, a clear photophysical picture of exciton transport is still lacking due to strong confinement effects and intricate exciton-phonon interactions in an organic-inorganic hybrid lattice. Herein, we present a systematical study on exciton transport in (BA)2(MA)n−1PbnI3n+1 Ruddlesden−Popper perovskites using time-resolved photoluminescence microscopy. We reveal that the free exciton mobilities in exfoliated thin flakes can be improved from around 8 cm2 V−1 s−1 to 280 cm2V−1s−1 by anchoring the soft butyl ammonium cation with a polymethyl methacrylate network at the surface. The mobility of the latter is close to the theoretical limit of Mott-Ioffe-Regel criterion. Combining optical measurements and theoretical studies, it is unveiled that the polymethyl methacrylate network significantly improve the lattice rigidity resulting in the decrease of deformation potential scattering and lattice fluctuation at the surface few layers. Our work elucidates the origin of high exciton mobility in Ruddlesden−Popper perovskites and opens up avenues to regulate exciton transport in two-dimensional materials.

Halide Ion Mobility in Paired 2D Halide Perovskites: Ruddlesden–Popper Versus Dion–Jacobson Phases

Abstract2D lead halide perovskites with tunable optoelectronic properties through modulating inorganic components and organic spacer ligands represent a promising candidate in perovskite optoelectronics. However, an intrinsic soft lattice of perovskites gives rise to a vacancy‐mediated halide ion migration, which further affects the long‐term stability of materials as well as devices. Here, halide ion mobility is evaluated using two different 2D perovskites yielded with butylammonium (BA) for the Ruddlesden–Popper (RP) phase and butane‐1,4‐diamine (BDA) for the Dion–Jacobson (DJ) phase, respectively. By probing the halide ion migration kinetics in the physically paired 2D bromide and iodide perovskite films, the softer lattice (RP) shows a lower activation energy of 50.9 kJ mol−1 as compared to that of more rigid lattice (DJ) of 60.8 kJ mol−1. Given similar halide diffusion pathlength and halide mixing chemical potential, the binding mode (RP and DJ) can indeed dictate the overall halide ion stability. Understanding such halide ion mobility is important in designing perovskites with increased stability and performances at material and device levels.

Simultaneous deep eutectic solvent based microextraction for monitoring Brilliant blue and rhodamine B in foodstuff and industrial samples

Brilliant blue (Bb) (legal food dye) and rhodamine b (Rb) (illegal food dye) are artificial dyes used in different industries such as food and cosmetic. Due to their toxic effects on humans, extreme exposure to these food additives can lead to health problems. Simultaneous deep eutectic solvent based (DES) microextraction method was developed first time for spectrophotometric determination of Bb and Rb. DES composed of 1-heptanol and tetra butyl ammonium bromide (TBAB) was synthesized and then used for simultaneous microextraction of Bb and Rb. Effects of pH, composition ratio and volume of DES, time of vortex mixing, centrifugation time and rate, sample volume and matrix components were investigated to achieve quantitative simultaneous microextraction of the dyes. The detection limits 20 and 13 µg/L, linear dynamic ranges between 0.068–4.5 and 0.042–3 µg/mL and 40 preconcentration factors were obtained for Bb and Rb, respectively. Bb and Rb contents of commercially available industrial samples were determined between 3.85–6.28 µg/mL and 1.05–23.50 µg/g for liquid and solid samples, respectively. Quantitative recoveries ranging from 92 to 106% were obtained in multivariable analyte addition-recovery tests. In addition to dye content determination process of real samples and method development studies, extraction mechanisms of method were elucidated for Bb and Rb. Green Analytical Procedure Index (GAPI) and score of Analytical Eco-Scale (AES) were evaluated.

Experimental study on mineral processing of shallow oxidation ore in a hydrothermal metasamatic sulfide gold mine

The ore produced by a gold mine in Fujian province belongs to hydrothermal metasomatism sulfide type gold (silver) ore, and the shallow oxidized ore of the deposit has a gold grade of 0.91g/t. In order to understand the selectability of this oxidized ore, the selectability test study is carried out. Through the beneficiation test study, the concentration of-0.074mm is 70%, the concentration of isoopyl yellow is 150g/t, the concentration of butyl ammonium black is 50g/t, and the concentrate products of 16.98g/t can be obtained, and the gold recovery rate is 74.04%.

Cyclic voltammetry studies of malonamide hydrazone derivative and its electrochemical effect on CdCl2

The purpose of this study is to detect the electrochemical reduction of a novel N-(benzo[d]thiazol-2-yl)-3-oxo-3-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)propenamide ligand (o-H2BMP) at varying pH by using a gold electrode in the presence of tetra butyl ammonium bromide as a supporting electrolyte at room temperature. The outcomes results showed that the effective reduction mechanism of the o-H2BMP ligand consumes 8 electrons and 8 hydrogen ions at pH 5, which belong to the reduction of azomethine and two carbonyl groups at (0.0518 V – 0.678 V), respectively. Also, the electrochemical behavior of Cd(II) ions in a cell containing 0.1 M KCl in 50 % (DMSO-water) mixed solvent by using glassy carbon electrode was proceeded with two electrons transfer as Cd+2/Cd0 in reversible mechanism. This work presents a novel structural analysis of the complexes that can be formed in solution and which exhibit stochiometric ratios of (M:L, 1:1, 2:3, 1:2). Moreover, the degree of reversibility of Cd(II) ions redox behavior was evaluated in the absence/presence of the o-H2BMP ligand which indicated that the redox behavior of Cd(II) ions more reversible in the case of free Cd(II) according to the ∆Ep, α, and kh values. While, in the presence of the o-H2BMP ligand, the degree of reversibility was decreased and the number of electrons transferred in the rate-determining step increased which confirming the complexation reaction of Cd(II) with the ligand.

Insights into the Growth Orientation and Phase Stability of Chemical-Vapor-Deposited Two-Dimensional Hybrid Halide Perovskite Films.

Chemical vapor deposition (CVD) offers a large-area, scalable, and conformal growth of perovskite thin films without the use of solvents. Low-dimensional organic-inorganic halide perovskites, with alternating layers of organic spacer groups and inorganic perovskite layers, are promising for enhancing the stability of optoelectronic devices. Moreover, their multiple quantum-well structures provide a powerful platform for tuning excitonic physics. In this work, we show that the CVD process is conducive to the growth of 2D hybrid halide perovskite films. Using butylammonium (BA) and phenylethylammonium (PEA) cations, the growth parameters of BA2PbI4 and PEA2PbI4 and mixed halide perovskite films were first optimized. These films are characterized by well-defined grain boundaries and display characteristic absorption and emission features of the 2D quantum wells. X-ray diffraction (XRD) and a noninteger dimensionality model of the absorption spectrum provide insights into the orientation of the crystalline planes. Unlike BA2PbI4, temperature-dependent photoluminescence measurements from PEA2PbI4 show a single excitonic peak throughout the temperature range from 20 to 350 K, highlighting the lack of defect states. These results further corroborate the temperature-dependent synchrotron-based XRD results. Furthermore, the nonlinear optical properties of the CVD-grown perovskite films are investigated, and a high third harmonic generation efficiency is observed.

Prominent reverse saturable absorption of lead-free two-dimensional organic-inorganic hybrid double perovskites promoted by defects

Two-dimensional (2D) organic-inorganic hybrid perovskites have exhibited prominent reverse saturable absorption (RSA), yet their practical application is hindered by the lack of a defect-tolerance performance-enhancing strategy and lead-related toxicity. This study demonstrates that the realization of RSA via excited-state absorption is an effective strategy to achieve defect-promoted RSA in a series of lead-free 2D hybrid double perovskites (A4AgBiBr8), where A represents propylammonium (PA), butylammonium (BA), and hexylammonium (HA). Among these, the (PA)4AgBiBr8 shows the best performance. The nonlinear absorption coefficient of the solution-phase deposited thin film is as high as (2.0 ± 0.3) × 104 cm GW−1, a value that is competitive with those of most mechanically-exfoliated 2D hybrid lead halide perovskites and inorganic monolayer/few-layer 2D materials. Spectral characterization and density functional theory calculation demonstrate that Br vacancies in A4AgBiBr8 introduce abundant defect states, which act as intermediate states and enable efficient excited-state absorption. Consequently, a larger number of defect states results in a stronger RSA response.

Investigation of kinetics of semi-clathrate formation for CO2 capture in the presence of L-methionine amino acid

ABSTRACT Gas hydrates cater to several applications including methane/natural gas storage, CO2 capture, gas separation, desalination, etc. Semi-clathrates are a class of inclusion compounds in which a part of guest molecule (typically anion of tertiary butyl ammonium salts) involves in the formation of cage structure along with water and the other remaining part of guest molecule (cation) occupies and stabilizes the gas hydrate structure. This study is the first effort to explore the kinetics of the formation of tertiary butyl ammonium chloride (TBAC) semi clathrate in the presence of CO2 without and with the addition of a kinetic promoter (L-methionine amino acid). Experimental conditions of the study include starting pressure of 3.4 MPa and temperatures in the range of 279.2–283.2 K. Kinetics of TBAB-CO2 and TBAC-CO2 mixed semi-clathrates have been compared and reported along with morphology observations under similar experimental conditions. TBAC-CO2 mixed semi-clathrates showcase significant reduction in induction time in comparison to TBAB-CO2 mixed semi-clathrates. Also, gas uptake (CO2 storage capacity) is observed to be slightly better for TBAC mixed semi-clathrates at lower concentrations (5 wt%). Though l-methionine amino acid aids in the reduction of t90 (time taken for 90% completion of hydrate formation) for TBAB-CO2 system, such an effect was not observed for TBAC-CO2 system. Formed semi-clathrates can be easily dissociated with low-grade waste heat to release the stored CO2 (based on the observed dissociation by thermal stimulation in conducted experiments), making it an excellent contender for Carbon Capture Utilization and Storage (CCUS) Technology.

Cation Migration in Physically Paired 2D and 3D Lead Halide Perovskite Films

Abstract2D/3D interfaces provide long‐term stability for the operation of metal halide perovskite solar cells. However, the cation migration under heat and light can disturb the interface and create a graded cation interface. This study has now probed the cation migration by physically pairing X2PbI4 (X = butylammonium BA, oleylammonium OA, or phenethylammonium PEA) 2D film and (CH3NH3, MA)PbI3 3D film at different temperatures and recording changes in the absorption and emission spectra. The migration of the methyl ammonium cation toward the 2D film slowly transforms the n = 1 layered phase into n = 2 and 3 layered phases. The 3D film, on the other hand, exhibits relatively small changes, as the inclusion of spacer cation has little effect on its phase. The apparent activation energy determined from the temperature‐dependent cation migration kinetics (Ea = 29– 50 kJ mol−1) indicates alkyl ammonium cations such as butyl ammonium migrate more readily into the 3D layer than aromatic cations such as PEA. The ease of migration of spacer cations between physically paired films suggests that the varied composition at the interface should be considered while evaluating the effectiveness of the 2D/3D design strategy for improving the performance of perovskite solar cells.

Molecular simulations of understanding the Na+ ion structure, dynamic and thermodynamic behavior in ionic liquids: Butyl ammonium hydrogen bisulfate and tri-butyl ammonium hydrogen bisulfate

This manuscript presents the all-atom molecular dynamics simulations to investigate intermolecular structure and solvation thermodynamics of Na+ ion in two different ammonium-based protic ionic liquids (1) Butyl Ammonium hydrogen bisulfate [BA+][HSO4−], (2) Tri-butyl ammonium hydrogen bisulfate [TBA+][HSO4−]. The ionic liquid [BA+][HSO4−] show a more coordinated behavior when compared to [TBA+][HSO4−], which is observed over the temperature range from 278 K to 348 K. Hydrogens of the cations show a hydrogen bonding interaction with oxygens of anions. The cationic [TBA+] molecules show more solvation behavior with anions when compared to the [BA+]. The Na+ ion show a strong coordination structure with [HSO4−] in [TBA+][HSO4−] when compared to the [BA+][HSO4−]. We further calculate the detailed solvation free energy (ΔG) calculations using thermodynamic integration. We found that the ΔG of Na+ is more favorable in [TBA+][HSO4−] when compared to [BA+][HSO4−] in the temperature range varying from 278 K to 348 K. With the temperature rise, we observe the more favorable solvation of Na+ in both ionic liquids. On the other hand, the solvation of Cl− becomes less favorable. Overall, this manuscript provides detailed molecular level structural and thermodynamic origins of Na+ in protic ionic liquids useful for designing and developing sustainable electrolytes for Na+ battery applications.

The strain regulation of atomic structure and properties on ultra-stable monolayer butylammonium-based halide perovskites: Insight from density functional theory

The two-dimensional (2D) monolayer butylammonium (BA)-based halide perovskites are applied for perovskite solar cells (PSCs) due to ultra-stable and highly crystalline. However, the systematic analysis has not been well conducted for 2D monolayer (BA)2BX4 (BPb, Sn; X = I, Br, Cl) perovskites. Here we systematically investigated the photoelectric and mechanical properties using density functional theory (DFT), further revealing the effect and mechanism of the direct and doping-modulated strain induced by external strain(stress) and pre-strain treatment technology. (BA)2PbI4, (BA)2SnI4 and (BA)2SnBr4 have excellent properties for PSCs. Based on the direct strain regulation, (BA)2SnBr4 exhibits smaller bandgaps and more stable atomic evolution than (BA)2PbI4, and better mechanical properties and smaller electrostatic macroscopic average potential difference (ΔP) than (BA)2SnI4. Based on the doping-modulated strain regulation on 2D (BA)2(Pb1-xSnx)X4, lower Pb-doping ratio induces the nonlinear dependence of bandgaps, which mainly originating from the local compressive strain effect on Sn crystal structure induced by larger Pb-atomic radius. Especially, the double-decker structure (Sn2Pb2-p) obtains excellent stability due to stress relaxation induced by in-inorganic layer homogeneity. We anticipate this work will provide the sufficient guidance for designing and fabricating green 2D or 2D/3D halide junction PSCs to improve both PCE and stability.

Synergistic Effect of Water-Soluble Hydroxylated Multi-Wall Carbon Nanotubes and Graphene Nanoribbons Coupled with Tetra Butyl Ammonium Bromide on Kinetics of Carbon Dioxide Hydrate Formation

In this work, the thermodynamics and kinetics of hydrate formation in 9.01 wt% tetra butyl ammonium bromide (TBAB) mixed with water-soluble hydroxylated multi-wall carbon nanotube (MWCNTol) systems were characterized by measuring hydrate formation conditions, induction time, and final gas consumption. The results showed that MWCNTols had little effect on the phase equilibrium of CO2 hydrate formation. Nanoparticles (graphene nanoribbons (GNs) and MWCNTols) could significantly shorten the induction time. When the concentration was ≤0.06 wt%, MWCNTols had a better effect on the induction time than the GN system, and the maximum reduction in induction time reached 44.22%. The large surface area of MWCNTols could provide sites for heterogeneous nucleation, thus shortening the induction time of hydrate formation. Furthermore, adding different concentrations of nanoparticles to the 9.01 wt% TBAB solution effectively increased the final gas consumption, and the maximum increase was 10.44% of the 9.01 wt% TBAB + 0.08 wt% GN system. Meanwhile, the suitable initial pressure and experimental temperature could also promote the hydrate formation and increase the motivation in hydrate formation. The 9.01 wt% TBAB + 0.02 wt% MWCNTol system had the best effect at 3.5 MPa and 277.15 K. The induction time was reduced by 66.67% and the final gas consumption was increased by 284.11% compared to those of the same system but at a different initial pressure and experimental temperature. This work helps to promote the industrial application of hydrate technology in CO2 capture and storage.