Ammonium Research Articles

Micro Solvation Effect of Methanol on Excited-State Dynamics of Protonated Tryptophan and Dopamine.

The electronic and vibrational cryogenic ion spectroscopy of protonated tryptophan (TrpH+) and dopamine (DAH+) complexed with methanol has been recorded. These two biological chromophores exhibit ultrafast photochemistry due to excited-state proton transfer (ESPT). We have established the relationship between the structure of the complexes and their photodynamics and compared them with recent results obtained in hydrated complexes. For TrpH+, there is no substantial change between methanol and water complexes; ESPT is hindered by a single solvent molecule. In the DAH+(MeOH)1 complex, the most stable conformer adopts a structure that prevents the direct interaction of the ammonium group of the side chain with the catechol ring, thus blocking the ESPT reaction. Such a ring structure is indeed a very minor populated conformer in the single-hydrated complex. The change in conformal stability between water and methanol clusters is due to a weak CH-π attractive interaction of the methyl group of methanol with the catechol.

Sulphur storage in cold molecular clouds: the case of the NH4+SH- salt on interstellar dust grains

Abstract In comets and in the cold phase of the interstellar medium (ISM), ammonium salts are key molecular species due to their role in the retention of volatile compounds on cold surfaces. In the case of sulphur, the H2S/OCS ratio observed in protostars could be explained by the presence of ammonium hydrosulphide (NH4SH) salts. However, laboratory data on the properties of NH4SH in ISM cold relevant conditions are rather scarce, as they usually focus on the atmosphere of Jupiter. We propose to consolidate the laboratory data regarding NH4SH on grains, by performing temperature programmed desorption experiments and Fourier transform infrared reflection spectroscopy. The salt was also exposed to H atoms to mimic the ISM conditions. NH4SH was found to form in situ at 10 K, from a mixture of ammonia (NH3) and hydrogen sulphide (H2S). The NH4+ infrared feature (1485 cm−1) is the most prominent one at 80 K. As pure species, H2S and NH3 desorb at 76 K and 90 K, respectively, whereas they are released into the gas phase at 153 K when adsorbed in the form of salt. The presence of water delays the desorption of the salt until the very end of the water desorption, but does not affect the desorption kinetics. During H-exposure, the salt is dissociated and no new product was detected. As a comparative study, salts have been included in the Nautilus gas-grain model. The results show a good correlation with the observations of IRAS 16293-2422B, as opposed to when NH2SH is not included in the model.

Ethanediamine Intercalation Induced Hydrogen Bond Network in Vanadium Oxide for Ultralong‐Life Aqueous Ammonium Ion Batteries

Aqueous ammonium‐ion batteries (AAIBs) have received tremendous attention as a potential energy technology, but their development is severely challenged by the fact that the as‐reported electrode materials are usually unable to meet the requirements of high capacity and high stability simultaneously. Herein, an organic‐inorganic hybrid material of ethanediamine (EDA) intercalated vanadium oxide (VO‐EDA) is synthesized as a high‐performance anode material for AAIBs. The intercalated EDA molecules not only act as an electron donor to bind with NH4+, but also form hydrogen bonding network structures with vanadium oxides to facilitate charge/ion transfer. As a result, this hybrid material provides a high specific capacity of 104.4 mAh g−1 at 0.5 A g−1 and good cycling stability after 5000 cycles 10 A g−1 with a coulombic efficiency of ~100%. Moreover, the ammonium‐ion full cell based on VO‐EDA anode and NiHCF cathode achieves a specific capacity of 55 mAh g−1 at 0.1 A g−1 and impressive cycling stability with 88.6% capacity retention after 10000 cycles at 5 A g−1.

Development of a Cone Homooxacalix[3]arene-Based Fluorescent Chemosensor for the Selective Detection of Biogenic Ammonium Ions in Protic Solvents.

We report here on the development of a fluorescent cone homooxacalix[3]arene-based receptor with a pyrene unit on the wide rim of the macrocycle (Ox3F) for the selective detection of primary ammonium ions, including those of biological importance. Ox3F was synthesized efficiently via an innovative strategy that enables the regio- and iteroselective wide rim functionalization of the readily available p-tBu-substituted homooxacalix[3]arene precursor. Nuclear magnetic resonance studies and in silico methods highlighted the endo-complexation of primary ammonium ions, including the protonated form of biogenic dopamine, tryptamine, serotonin, mexamine, and 3-iodothyronamine. The binding mode is similar for all guests with the ion deeply inserted into the polyaromatic cavity, enabling the NH3+ head to establish three hydrogen bonds with the ethereal oxygens of the macrocycle. Fluorescence quenching of the pyrene unit was observed following the π-π interaction between the pyrene moiety and the aromatic groups of serotonin, mexamine, and 3-iodothyronamine. No quenching was observed upon complexation of the smaller aromatic neurotransmitter dopamine as well as aliphatic amines and polyamines. This study presents a novel approach for biologically relevant ammonium ion chemosensing with ongoing efforts focused on translating these systems for aqueous environment applications.

A Multielectron and High-Potential Spirobifluorene-based Posolyte for Aqueous Redox Flow Batteries.

The rising energy demand driven by human activity has posed pressing challenges in embracing renewable energy, necessitating advances in energy storage technologies to maximize their utilization efficiency. Recent studies in aqueous organic redox flow batteriesfocused primarily on the development of organic negative electrolytes, while the progress in organic positive electrolytes remains constrained by limitations in their redox potentials and effective electron concentrations. Herein, we report a spatially twisted chlorinated spirobifluorene ammonium salts (CSFAs), created through an unexpected green chlorination-protection pathway during the initial cycling in flow battery, utilizing chloride ions from counterions in aqueous solution. The chlorinated, nonplanar spiral structure of CFSAs possesses a one-step four-electron transfer electrochemical property and offers exceptional resistance to nucleophilic attacks, exhibiting an unprecedented redox potential as high as 1.05 V (vs. SHE). A full redox flow battery based on CFSA-Cl (chloride ions as the counter ions) with 1.4 M electron concentration achieved an average coulombic efficiency exceeding 99.4% and a capacity utilization reaching 95% of the four-electron capacity for a stable cycling over 250 cycles (~22 days). The present work exemplifies the use of side reactions to develop new redox species, which can be extended to create more structurally versatile energy storage materials.

Bottom-up fabrication of DABCO-based bicationic ionic liquid-grafted MIL-101(Cr): Facilitating simultaneous activation of CO2 and epoxides for cyclic carbonate synthesis

Efficient activation of substrates as an orthogonal pathway for facilitating CO2 fixation into cyclic carbonates, poses ongoing challenges for the ingenious design and development of heterogeneous cooperative catalysts. Herein, a bottom-up strategy was employed to stepwise graft chloromethyl, triethylenediamine (DABCO), and chloroethylamine onto the organic linkers, forming bicationic ionic liquid tethered to MIL-101(Cr). The introduced –NH2 and quaternary ammonium groups dangling within the micro-mesopores ensured the fast enrichment and polarization of CO2 molecules, while the inherent unsaturated Cr3+ sites bonded with the epoxides to promote the simultaneous activation. The ample Cl- counter-anions further nucleophilically attacked to proceed the ring opening process, triggering an upgradation in catalytic performance for cycloaddition. After optimized by the response surface methodology (RSM), a chloropropene carbonate (CPC) yield of 97.8 % with a selectivity of 99.3 % were attained over the developed Cl[TNH2]Cl@MIL-101(Cr) at mild conditions (104.5 °C, 1.07 MPa, 3.75 wt% of catalyst, 1.91 h) in the absence of any solvent or co-catalyst. Furthermore, Cl[TNH2]Cl@MIL-101(Cr) displayed good durability, universality, and recyclability. The synergy of multiple sites was testified by the in-situ DRIFTS spectra and DFT calculations, and thus the potential catalytic mechanism was deduced. The implement of this work could shed some lights on the rational assembling of robust IL@MOFs nanocomposites and offered novel avenues for the fabrication of high-efficiency catalysts for practical CO2 conversion.

An Evaluation of the Corrosion Inhibition Performance of Chitosan Modified by Quaternary Ammonium Salt for Carbon Steel in Stone Processing Wastewater

Chitosan was used as the raw material. A quaternization reaction was carried out between 2,3-epoxypropyltrimethylammonium chloride and water-soluble chitosan to prepare quaternary ammonium salt water-soluble chitosan (QWSC), and its corrosion inhibition performance against the corrosion of carbon steel in stone processing wastewater was evaluated. The corrosion inhibition efficiencies of QWSC on carbon steel in stone processing wastewater were investigated through weight loss, as well as electrochemical and surface morphology characterization techniques. The results show that QWSC has superior corrosion inhibition performance for A3 carbon steel. When an amount of 60 mL·L−1 is added, the corrosion inhibition efficiency can reach 59.51%. Electrochemical research has shown that a QWSC inhibitor is a mixed-type corrosion inhibitor. The inhibition mechanisms of the QWSC inhibitor revealed that the positive charge on the surface of carbon steel in stone wastewater was conducive to the adsorption of Cl− in the medium, which produced an excessive negative charge on the metal’s surface. At the same time, the quaternary ammonium cation and amino cation formed in QWSC in stone processing wastewater can be physically absorbed on the surface of A3 carbon steel, forming a thin-film inhibitor to prevent metal corrosion.

Research on the corrosion inhibition performance and mechanism of pyrimidine quaternary ammonium salt

Purpose At present, research on the preparation of corrosion inhibitors using modified pyrimidine derivatives is still blank. The purpose of this study is to synthesize a new cationic mercaptopyrimidine derivative quaternary ammonium salt, known as DTEBTAC, that can be used as a corrosion inhibitor to slow down the metal corrosion problems encountered in oil and gas extraction processes. Design/methodology/approach A new corrosion inhibitor was synthesized by the reaction of anti-Markovnikov addition and nucleophilic substitution. The weight loss method was used to study the corrosion inhibition characteristics of synthetic corrosion inhibitors. Electrochemical and surface topography analyses were used to determine the type of inhibitor and the adsorption state formed on the surface of N80 steel. Molecular dynamics simulations and quantum chemistry calculations were used to investigate the synthetic corrosion inhibitor’s molecular structure and corrosion inhibition mechanisms. Findings The results of the weight loss method show that when the dosage of DTEBTAC is 1%, the corrosion rate of N80 steel in hydrochloric acid solution at 90? is 3.3325 g m-2 h-1. Electrochemical and surface morphology analysis show that DTEBTAC can form a protective layer on the surface of N80 steel, and is a hybrid corrosion inhibitor that can inhibit the main anode. Quantum chemical parameter calculation shows that DTEBTAC has a better corrosion inhibition effect than DTP. The molecular dynamics simulation results show that DTEBTAC has stronger binding energy than DTP, and forms a network packing structure through hydrogen bonding, and the adsorption stability is enhanced. Originality/value A novel cationic mercaptopyrimidine derivative quaternium-ammonium salt corrosion inhibitor was designed and provided. Compared with the prior art, the preparation method of the synthesized mercaptopyrimidine derivative quaternary ammonium salt corrosion inhibitor is simple, and the presence of nitrogen-positive ions, sulfur atoms and nitrogen-rich atoms has an obvious corrosion inhibition effect, which can be used to inhibit metal corrosion during oil and gas field exploitation. It not only expands the application field of new materials but also provides a new idea for the research and development of new corrosion inhibitors.

Elucidating and Optimizing the Photochemical Mechanism of Coumarin-Caged Tertiary Amines.

Photoactivatable or "caged" pharmacological agents combine the high spatiotemporal specificity of light application with the molecular specificity of drugs. A key factor in all optopharmacology experiments is the mechanism of uncaging, which dictates the photochemical quantum yield and determines the byproducts produced by the light-driven chemical reaction. In previous work, we demonstrated that coumarin-based photolabile groups could be used to cage tertiary amine drugs as quaternary ammonium salts. Although stable, water-soluble, and useful for experiments in brain tissue, these first-generation compounds exhibit relatively low uncaging quantum yield (Φu < 1%) and release the toxic byproduct formaldehyde upon photolysis. Here, we elucidate the photochemical mechanisms of coumarin-caged tertiary amines and then optimize the major pathway using chemical modification. We discovered that the combination of 3,3-dicarboxyazetidine and bromine substituents shift the mechanism of release to heterolysis, eliminating the formaldehyde byproduct and giving photolabile tertiary amine drugs with Φu > 20%─a 35-fold increase in uncaging efficiency. This new "ABC" cage allows synthesis of improved photoactivatable derivatives of escitalopram and nicotine along with a novel caged agonist of the oxytocin receptor.

Contribution of Electrostatic CH3-π Interactions to Recognition of Histone Asymmetric Dimethylarginine by the SPIN1 Triple Tudor Domain.

Methylation of arginine (Arg) residues on histones creates a new binding epitope, enabling recognition by aromatic cage binding pockets in Tudor domains; these protein-protein interactions (PPIs) govern gene expression. Despite their biological importance, the molecular details of methylated Arg recognition are poorly understood. While the desolvation, hydrogen bonding, and guanidinium stacking of methylated Arg have been explored in model systems and proposed to contribute to binding, direct interactions between the methyl groups and the aromatic residues in the binding pocket have not previously been investigated. Herein, we mechanistically study the CH3-π interactions between the SPIN1 triple Tudor domain and histone asymmetric dimethylarginine. We find that these CH3-π interactions are electrostatically tunable, exhibiting cation-π character, albeit attenuated relative to cation-π interactions with quaternary ammonium ions, offering key insight into how methylation of Arg alters its binding epitope to enable new PPIs.

Exogenous Metal Cations in the Synthesis of CsPbBr3 Nanocrystals and Their Interplay with Tertiary Amines.

Current syntheses of CsPbBr3 halide perovskite nanocrystals (NCs) rely on overstoichiometric amounts of Pb2+ precursors, resulting in unreacted lead ions at the end of the process. In our synthesis scheme of CsPbBr3 NCs, we replaced excess Pb2+ with different exogenous metal cations (M) and investigated their effect on the synthesis products. These cations can be divided into two groups: group 1 delivers monodisperse CsPbBr3 cubes capped with oleate species (as for the case when Pb2+ is used in excess) and with a photoluminescence quantum yield (PLQY) as high as 90% with some cations (for example with M = In3+); group 2 yields irregularly shaped CsPbBr3 NCs with broad size distributions. In both cases, the addition of a tertiary ammonium cation (didodecylmethylammonium, DDMA+) during the synthesis, after the nucleation of the NCs, reshapes the NCs to monodisperse truncated cubes. Such NCs feature a mixed oleate/DDMA+ surface termination with PLQY values of up to 97%. For group 1 cations this happens only if the ammonium cation is directly added as a salt (DDMA-Br), while for group 2 cations this happens even if the corresponding tertiary amine (DDMA) is added, instead of DDMA-Br. This is attributed to the fact that only group 2 cations can facilitate the protonation of DDMA by the excess oleic acid present in the reaction environment. In all cases studied, the incorporation of M cations is marginal, and the reshaping of the NCs is only transient: if the reactions are run for a long time, the truncated cubes evolve to cubes.

Anethole Regulated Crystallization for High Efficiency Carbon‐Based Perovskite Solar Cells

AbstractTwo‐step sequential deposition is a widespread technique for the fabrication of perovskite films, renowned for its better control of the crystallization process. However, achieving a well‐controlled and complete reaction of PbI2 by organic ammonium salts remains a key challenge. Previous studies have predominantly focused on regulating the properties of the PbI2 layer while paying less attention to the high reactivity of organic ammonium salts. In this study, the natural molecule anethole is first explored to control perovskite crystallization during two‐step sequential deposition, focusing on the reactivity modulation of organic formamidine ion (FA+). It is demonstrated that FA+ exhibits strong hydrogen bond interactions with anethole, inhibiting the high reactivity of FA+ and effectively delaying the rapid reaction between FAI and PbI2. This decelerates the crystallization kinetics of perovskite films, facilitating the orderly and complete reaction of PbI2 by FAI while suppressing detrimental δ‐phase formation. Consequently, FA‐based perovskite films with high crystallinity, preferred orientation, and low defect state density are obtained. The fabricated planar hole transport layer‐free carbon electrode perovskite solar cells deliver an efficiency of 20.41% (certified efficiency of 20.0%), which is a new record for this kind of solar cell.

A Comprehensive Review of Ammonium Ion Hybrid Supercapacitors: Exploring Recent Breakthroughs and Future Horizons

A Comprehensive Review of Ammonium Ion Hybrid Supercapacitors: Exploring Recent Breakthroughs and Future Horizons

Cover Picture

4‐(2‐Hydroxyethyl)piperazin‐1‐ium iodide (PZOI) is a functional ammonium salt that can simultaneously reduce shallow/deep‐level defect densities by passivation effect and form 2D component, respectively. These advances reduce the energy loss of single‐junction devices and significantly enhance the efficiency and stability of perovskite/organic tandems. More details are discussed in the article by Li et al. on page 1819—1827.image

Comparative proteomics analysis of root and nodule mitochondria of soybean.

Legumes perform symbiotic nitrogen fixation through rhizobial bacteroids housed in specialised root nodules. The biochemical process is energy-intensive and consumes a huge carbon source to generate sufficient reducing power. To maintain the symbiosis, malate is supplied by legume nodules to bacteroids as their major carbon and energy source in return for ammonium ions and nitrogenous compounds. To sustain the carbon supply to bacteroids, nodule cells undergo drastic reorganisation of carbon metabolism. Here, a comprehensive quantitative comparison of the mitochondrial proteomes between root nodules and uninoculated roots was performed using data-independent acquisition proteomics, revealing the modulations in nodule mitochondrial proteins and pathways in response to carbon reallocation. Corroborated our findings with that from the literature, we believe nodules preferably allocate cytosolic phosphoenolpyruvates towards malate synthesis in lieu of pyruvate synthesis, and nodule mitochondria prefer malate over pyruvate as the primary source of NADH for ATP production. Moreover, the differential regulation of respiratory chain-associated proteins suggests that nodule mitochondria could enhance the efficiencies of complexes I and IV for ATP synthesis. This study highlighted a quantitative proteomic view of the mitochondrial adaptation in soybean nodules.

Strong Enhancement in Cobalt(II) TPMA Aqueous Hydrogen Photosynthesis through Intramolecular Proton Relay.

Photosynthetic hydrogen generation by cobalt(II) tris(2-pyridilmethyl)amine (TPMA) complexes is mainly limited by protonation kinetics and decomposition routes involving demetallation. In the present work we have explored the effects of both proton shuttles and improved rigidity on the catalytic ability of cobalt(II) TPMA complexes. Remarkably, we demonstrate that, while a small enhancement in the catalytic performance is attained in a rigid cage structure, the introduction of ammonium groups as proton transfer relays in close proximity to the cobalt center allows to reach a 4-fold increase in the quantum efficiency of H2 formation, and a surprising 22-fold gain in the maximum turnover number, at low catalyst concentration. The beneficial role of the ammonium relays in promoting faster intramolecular proton transfer to the reduced cobalt center is documented by transient absorption spectroscopy, showcasing the great relevance of tuning the catalyst periphery to achieve efficient catalysis of solar fuel formation.

Strong Enhancement in Cobalt(II) TPMA Aqueous Hydrogen Photosynthesis through Intramolecular Proton Relay

Photosynthetic hydrogen generation by cobalt(II) tris(2‐pyridilmethyl)amine (TPMA) complexes is mainly limited by protonation kinetics and decomposition routes involving demetallation. In the present work we have explored the effects of both proton shuttles and improved rigidity on the catalytic ability of cobalt(II) TPMA complexes. Remarkably, we demonstrate that, while a small enhancement in the catalytic performance is attained in a rigid cage structure, the introduction of ammonium groups as proton transfer relays in close proximity to the cobalt center allows to reach a 4‐fold increase in the quantum efficiency of H2 formation, and a surprising 22‐fold gain in the maximum turnover number, at low catalyst concentration. The beneficial role of the ammonium relays in promoting faster intramolecular proton transfer to the reduced cobalt center is documented by transient absorption spectroscopy, showcasing the great relevance of tuning the catalyst periphery to achieve efficient catalysis of solar fuel formation.

Graphene nanoribbon hydrogel scaffold for highly conductive and robust polyimide nanocomposite

Although highly loaded graphitic nanocarbon materials effectively enhance the electrical, mechanical, and thermal properties of polymeric materials, their practical implementation has been hindered by severe aggregation issues. Here, we propose a method to achieve homogeneous nanocarbon-polyimide (PI) composites by integrating graphene oxide nanoribbons (GONRs) with polyamic acid ammonium (PAA) salt, a precursor of PI. Self-assembled scaffold structure of GONRs hydrogel enables the uniform integration and immobilization of PAA within the GONR scaffold, mitigating aggregation concerns. The resulting GONR/PAA hydrogel, formed through physical interactions, can be coated onto substrates via a shear stress-induced bar coating method due to its viscoelastic rheological properties. Subsequent heat treatment at 400 °C triggers the imidization reaction of PAA and the reduction of GONR, facilitating the formation of uniformly integrated GNR/PI nanocomposite coatings. Under optimized conditions, incorporating a high-loading GONR content in PAA (95 wt% of GONR and 5 wt% of PAA) yielded GNR/PI composites with excellent mechanical properties, exhibiting a hardness of 0.75 GPa and an elastic modulus of 8.3 GPa. Additionally, this GNR/PI composite displayed a good electrical conductivity of 3890 S/m, attributed to the electrical pathways formed by GNRs within the PI matrix.

Structure-activity correlation for new phosphorylated quaternary ammonium salts: To antimicrobial activity via self-organization

The impact of the hydrocarbon tail length on the physicochemical properties of N-((diisopropoxyphosphoryl)methyl)-N,N-dimethyl-N-alkylammonium bromides (CnPN+Br-, where n = 10, 12, 14, 16, 18) was studied through surface tension, electrical conductivity, and spectral characteristics of hydrophobic probes (Orange OT, pyrene) measurements. In homologous series, the values of the critical micelle concentration (cmс) decrease and reach the micromolar range for hexadecyl and octadecyl derivatives. Surface tension isotherms were used to determine the maximum surface excess (Γmax), the minimum area per surfactant molecule at the air/water interface (Amin), and the Gibbs free energy of micelle formation (∆Gmic) and adsorption (∆Gad). Thermodynamic parameters (ΔGmic, ΔHmic, ΔSmic) and counterion binding degree values (β) were calculated from the temperature dependences of specific electrical conductivity on the CnPN+Br- concentration. It was established that micellization is a spontaneous and entropy-driven process. Additionally, aggregation numbers of CnPN+Br- were obtained from steady-state fluorescence quenching and dye solubilization techniques. It was established that the investigated cationic surfactants exhibit membranotropic activity against gram-positive bacteria Staphylococcus aureus, caused by depolarization of bacterial cytoplasmic membrane.

Bioconversion of Apple Pomace to Meyerozyma guilliermondii and Scheffersomyces stipitis Biomass

Poland is one of the leading apple-producing countries, both in Europe and around the world. One of the main byproducts of apple processing is pomace, which can account for 20–35% of the harvested apples. Pomace is a potential source of many valuable bioactive components and can also serve as a food ingredient, either directly or indirectly (after bioconversion with fodder yeast). This study aimed to evaluate the possibility of converting polysaccharides contained in apple pomace to yeast biomass. Meyerozyma guilliermondii and Scheffersomyces stipitis yeasts were grown in a medium prepared by pretreatment of the raw material with water or 2% sulphuric acid at 120 °C. Subsequently, enzymatic hydrolysis was performed using a Cellic CTec2 preparation at 30 °C or 50 °C. The resulting hydrolysates were enriched with ammonium salts, and shaken yeast cultures were incubated at 30 °C for 72 h. Based on the results, it can be concluded that acid pretreatment of apple pomace is more effective than water pretreatment under the same time and temperature conditions. The Meyerozyma guilliermondii strain grows in apple pomace hydrolysates more efficiently (16.29 g/L) than Scheffersomyces stipitis cells do (14.63 g/L).