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The structure of the title compound, [Ni2(C9H10NO2)4], is built up by discrete centrosymmetric dimers. Two nitrogen and three oxygen atoms of two Schiff base ligands singly deprotonated at the phenolate site form a square-pyramidal environment for each metal atom. The ligands are bonded differently to the metal centre: one of the phenolic O atoms is bound to one nickel atom, whereas another bridges the two metal atoms to form the dimer. The Ni--N/O distances fall in the range 1.8965 (13)-1.9926 (15) Å, with the Ni--N bonds being slightly longer; the fifth contact of the metal to the bridging phenolate oxygen atom is substantially elongated [2.533 (1) Å]. A similar coordination geometry was observed in the isomorphous Cu analogue previously reported by us [Sydoruk et al. (2013[Sydoruk, T. V., Buvaylo, E. A., Kokozay, V. N., Vassilyeva, O. Y. & Skelton, B. W. (2013). Acta Cryst. E69, m551-m552.]). Acta Cryst. E69, m551-m552]. In the crystal, the [Ni2L4] molecules form sheets parallel to the ab plane with the polar methoxy groups protruding into the intersheet space and keeping the sheets apart. Within a sheet, the molecules are stacked relative to each other in such a way that the Ni2O2 planes of neighbouring molecules are orthogonal. [ABSTRACT FROM AUTHOR]

An easy and scalable methylamine (MA) gas healing method was realized for inorganic cesium‐based perovskite (CsPbX3) layers by incorporating a certain amount of MAX (X=I or Br) initiators into the raw film. It was found that the excess MAX accelerated the absorption of the MA gas into the CsPbX3 film and quickly turned it into a liquid intermediate phase. Through the healing process, a highly uniform and highly crystalline CsPbX3 film with enhanced photovoltaic performance was obtained. Moreover, the chemical interactions between a series of halides and MA gas molecules were studied, and the results could offer guidance in further optimizations of the healing strategy. A facile and scalable methylamine (MA) gas healing method for inorganic cesium‐based perovskite (CsPbX3) layers is based on incorporating a certain amount of MAX (X=I or Br) initiators into the raw film. The excess MAX accelerated the absorption of the MA gas into the CsPbX3 film and the formation of a liquid intermediate phase, enabling the formation of a highly uniform and crystalline CsPbX3 film with enhanced photovoltaic performance. [ABSTRACT FROM AUTHOR]

Electrochemical water splitting is one of the most important ways to produce hydrogen fuel for an environmentally friendly energy system. Low‐cost and efficient electrocatalysts for oxygen evolution reaction (OER) have been studied to overcome the sluggish kinetics of OER, which is considered to be a bottleneck that affects the overall efficiency of water splitting. However, the atomic‐level understanding and control of the catalyst surface still remains elusive. Here, we show that methylamine treatment of manganese oxide nanoparticles can effectively control their surface charge and enhance their OER catalytic activity under neutral condition. Methylamine treatment can reduce the overpotential for OER by nearly 100 mV at the current density 5 mA cm−2. Through spectroscopic studies, potentiometric titration, and zeta potential analysis, we discovered that methylamine does not exist on the surface after methylamine treatment but deprotonates the surface of nanoparticles and induce additional negative charge on the surface. Surprisingly, treatment with not only methylamine but other amines can also improve the OER performance and the catalytic activity of the amine treated nanoparticles is influenced by the pKa values of amines. Underwater stars: After methylamine treatment of OH− ligand exchanged Mn3O4 nanoparticles, oxygen evolving reaction performance is significantly enhanced. Detailed mechanistic study reveals that methylamine deprotonates the surface and generates additional negative charges on the surface. The catalytic performance could also be enhanced with different amines and the decrease in overpotential is associated with pKa of amines. [ABSTRACT FROM AUTHOR]

The mechanism of photochemical hydrogen atom transfer from an amine to a triplet nitro compound has been studied using monomethylamine and triplet nitromethane as an example. Two variants of the reaction have been considered: the transfer of hydrogen from the amino group and from the methyl group. The simulation has been carried out by quantum chemistry methods using the B2PLYP/cc-pVDZ functional. Complexation in pre- and postreaction complexes has been shown in terms of the theory of atoms in molecules. The profiles of potential energy surface of the reactions have been constructed. It has been concluded that the reaction of hydrogen transfer from the methyl group is energetically more favorable. It has been established that a strong hydrogen-bonded complex is formed during the reaction. [ABSTRACT FROM AUTHOR]

The conversion of methylamine (CH 3 NH 2 , 1000 ppm) has been studied in an atmospheric-pressure flow reactor from both experimental and modeling points of view. Several values of the oxygen excess ratio (λ), from pyrolysis to fuel-lean conditions, have been tested, and a large number of different species have been quantified experimentally by three different diagnostic techniques: gas chromatography, Fourier Transform Infra-red spectroscopy (FTIR) and an infra-red NO analyzer. For the first time, the influence of NO addition (500 and 1000 ppm) on the stoichiometric oxidation of methylamine has also been experimentally evaluated, and the main products of such interaction have been identified. Results indicate that, unlike the little influence of oxygen availability on methylamine conversion, the presence of different concentrations of NO promotes methylamine oxidation at lower temperatures. A literature mechanism has been validated against the present experimental data since previous experimental works under these conditions are scarce. The largest discrepancies have been found for the formation of NH 3 and NO as oxidation products, which are under and overestimated by the model, respectively, and under pyrolysis conditions, where modification of the kinetic parameters for the reaction CH 2 NH 2 ⇌ CH 2 NH + H from the original mechanism notably improves the agreement between experimental and simulated results. [ABSTRACT FROM AUTHOR]

[Display omitted] We undertook density functional theory (DFT) computations for inspecting the decomposition and adsorption of methylamine (MLA) onto the surface of a pure boron nitride nano-tube (BNNT). We also obtained the activation energies of viable elementary reactions and the adsorption energies of stable complexes. The most suitable reaction pathway which generated one hydrogen cyanide molecule as well as 4 hydrogen atoms was relatively endothermal. For MLA decomposition, the energy barrier was around 44.6 kcal/mol. Due to the fact that the activation energy for the side reaction which generated NH 2 as well as CH 3 was somewhat high, reducing the temperature could depress the generation of side products. [ABSTRACT FROM AUTHOR]

A new solvent system for PbI2 based on HI solution in acetone with a low boiling point is proposed. High solubility of PbI2 is caused by the formation of iodoplumbate complexes, and reaches a concentration of 1.6 M. Upon its crystallization metastable solvate phases PbI2∙HI∙n{(CH3)2CO} are formed. The latter allows for their easy deposition on substrates in a form of smooth and uniform thin films by spin-coating. Through a fast acid-base reaction with a gaseous amine, the films of the intermediate phase can be completely converted to single-phase perovskite films. The developed method allows one to form smooth perovskite films with high crystallinity with a thickness up to 1 μm. Due to easy and fast processing, the developed method can be promising for perovskite technology upscaling.

In the title compound, [CoBr(CH5N)(C2H8N2)2]Br2, the cobalt(III) ion has a distorted octahedral coordination environment and is ligated by four N atoms in the equatorial plane, with an additional N atom and a Br− ion occupying the axial positions. In the crystal, the complex cation and the two counter-anions are linked via N—H...Br and C—H...Br hydrogen bonds, forming a supramolecular framework.

Methylamine plays an important role in the global carbon and nitrogen budget; microorganisms that grow on reduced single carbon compounds, methylotrophs, serve as a major biological sink for methylamine in aerobic environments. Two non-orthologous, functionally degenerate routes for methylamine oxidation have been studied in methylotrophic Proteobacteria: Methylamine dehydrogenase and the N-methylglutamate pathway. Recent work suggests the N-methylglutamate (NMG) pathway may be more common in nature than the well-studied methylamine dehydrogenase (MaDH, encoded by the mau gene cluster). However, the distribution of these pathways across methylotrophs has never been analyzed. Furthermore, even though horizontal gene transfer (HGT) is commonly invoked as a means to transfer these pathways between strains, the physiological barriers to doing so have not been investigated. We found that the NMG pathway is both more abundant and more universally distributed across methylotrophic Proteobacteria compared to MaDH, which displays a patchy distribution and has clearly been transmitted by HGT even amongst very closely related strains. This trend was especially prominent in well-characterized strains of the Methylobacterium extroquens species, which also display significant phenotypic variability during methylamine growth. Strains like Methylobacterium extorquens PA1 that only encode the NMG pathway grew on methylamine at least five-fold slower than strains like Methylobacterium extorquens AM1 that also possess the mau gene cluster. By mimicking a HGT event through the introduction of the M. extorquens AM1 mau gene cluster into the PA1 genome, the resulting strain instantaneously achieved a 4.5-fold increase in growth rate on methylamine and a 11-fold increase in fitness on methylamine, which even surpassed the fitness of M. extorquens AM1. In contrast, when three replicate populations of wild type M. extorquens PA1 were evolved on methylamine as the sole carbon and energy source for 150 generations neither fitness nor growth rate improved. These results suggest that the NMG pathway permits slow growth on methylamine and is widely distributed in methylotrophs; however, rapid growth on methylamine can be achieved quite readily through acquisition of the mau cluster by HGT.

Abstract Low molecular weight (LMW) compounds are key intermediates in organic matter degradation and their metabolism supports a diverse microbial community in anoxic sediments. Much remains to be learned about the metabolic pathways and turnover rates of LMW compounds as well as the factors that influence their metabolism in the environment. We studied the microbial metabolism of acetate, methanol and methylamine in sediments from Northern Gulf of Mexico to elucidate their role as energy and carbon sources for microorganisms mediating terminal metabolic processes and to constrain the importance of C1 and C2 metabolism in the sedimentary carbon cycle. In terms of carbon flow, methanogenesis was a minor process in sulfate-rich sediments; acetate and methanol were oxidized primarily by non-methanogenic heterotrophs as an energy source. A large fraction of utilized acetate (20–76%) was assimilated into biomass, suggesting that acetate was a significant biomass-building source. In situ thermodynamic calculations suggested the utilization of acetate and methanol by sulfate-reducing bacteria was more favorable than the utilization by methanogens, consistent with the observed higher oxidation rates than methanogenesis rates as well as results from inhibitor experiments employing 2-bromoethanesulfonate and molybdate. Methylamine, by contrast, was utilized for methane production (up to 100%), but its utilization was not limited to methanogens. At an organic-poor deep-sea site, elevated acetate and methanol oxidation rates in the absence of sulfate-reducing and methanogenic activity indicated that metabolism of LMW compounds was coupled to other electron accepting processes, such as denitrification. Heterotrophic carbon assimilation was an important pathway for generating biomass at this site, as evidenced by comparable rates of acetate assimilation to bicarbonate incorporation. The oxidation and assimilation rates of LMW compounds generally decreased with sediment depth, following the trend of organic carbon degradation rates. Environmental factor, such as temperature but not pressure, affected the metabolism of LMW compounds; the oxidation of acetate, methanol and methylamine exhibited distinct responses to changes in temperature. In seep sediments, the oxidation of acetate and methanol accounted for 5% and 0.9%, respectively, of the total organic carbon oxidation. Collectively, this assessment of C1 and C2 LMW compound utilization shows that these compounds serve as energetic substrates to fuel methanogens, sulfate reducers and other microbes. [ABSTRACT FROM AUTHOR]

A facultative methylotroph, strain 2AzMo (VKM Ac-2782), was isolated from the coastal zone of the Sea of Azov. The cells of the isolate are aerobic gram-positive nonmotile rods. Optimal growth occurs at 1% NaCl, 28°C, and pH 7.5 with 1% СH3OH or 0.3% methylamine as the carbon and energy sources. A broad spectrum of polycarbon substrates is also utilized. Sequencing of the 16S rRNA gene of the strain revealed its similarity to Rhodococcus species: 99.9% to R. wratislaviensis IEGM 1112T (=NCIMB 13082T), 99.4% to R. imtechensis IEGM 940T (=RKJ300T), and 99.2% to R. koreensis IEGM 962T (=DNP505T). The level of DNA–DNA homology of strain 2AzMo with R. wratislaviensis IEGM 1112T (=NCIMB 13082T) was 76%, supporting its identification as a strain of this species. However, unlike strain 2AzMo, the type strain R. wratislaviensis IEGM 1112T, as well as other members of this genus (R. imtechensis IEGM 940T, R. koreensis IEGM 962T, and R. opacus IEGM 716T), do not grow on methanol and methylamine. Methanol oxidation by R.wratislaviensis 2AzMo is catalyzed by alcohol dehydrogenase, which uses 4-nitroso-N,N-dimethylaniline as an artificial electron acceptor. Methylamine is oxidized by methylamine dehydrogenase and the enzymes of the N-methylglutamate pathway. Formaldehyde is then assimilated via the fructose bisphosphate aldolase variant of the ribulose monophosphate pathway of C1 metabolism. Ammonium is assimilated by α-ketoglutarate reductive amination and via the glutamate cycle. [ABSTRACT FROM AUTHOR]

Carbaryl is the most widely used carbamate family pesticide, and its persistent nature causes it to pollute both soil and water ecosystems. Microbes maintain the Earth's biogeochemical cycles by metabolizing various compounds present in the matter, including xenobiotics, as a sole source of carbon, nitrogen, and energy. Soil isolate Pseudomonas sp. strain C5pp metabolizes carbaryl efficiently as the carbon source. Periplasmic carbaryl hydrolase catalyzes the conversion of carbaryl to 1-naphthol and methylamine. 1-Naphthol was further used as a carbon source via gentisate, whereas the metabolic fate of methylamine is not known. Here, we demonstrate that strain C5pp showed efficient growth on carbaryl when supplied as a carbon and nitrogen source, suggesting that the methylamine generated was used as the nitrogen source. Genes involved in the methylamine metabolism were annotated and characterized at the biochemical and molecular level. Transcriptional and enzyme activity studies corroborate that the γ-glutamylmethylamide/Nmethylglutamate (GMA/NMG) pathway is involved in the metabolism of carbaryl and methylamine as a nitrogen source. Compared to carbaryl, methylamine was found to be an effective inducer for the metabolic and transporter genes. Strain C5pp also harbored genes involved in sarcosine metabolism that were cotranscribed and induced by sarcosine. The presence of inducible pathways for metabolism of carbaryl as a nitrogen and carbon source helps in complete and efficient mineralization of carbaryl by strain C5pp, thereby maintaining the biogeochemical cycles. IMPORTANCE The degradation of xenobiotics plays a significant role in the environment to maintain ecological systems as well as to prevent the imbalance of biogeochemical cycles via carbon-nitrogen cycling. Carbaryl is the most widely used pesticide from the carbamate family. Pseudomonas sp. strain C5pp, capable of utilizing carbaryl as a carbon and nitrogen source for its growth, subsequently helps in complete remediation of carbaryl. Thus, it maintains the ecosystem by balancing the biogeochemical cycles. The metabolic versatility and genetic diversity of strain C5pp for the transformation of contaminants like carbaryl and 1-naphthol into less harmful products make it a suitable candidate from the perspective of bioremediation. [ABSTRACT FROM AUTHOR]

The first methylamine complexes of gold are reported. Both crystallize in chiral trigonal space groups. In bis(methylamine)gold(I) chloride [(CH3NH2)2Au]+ Cl−, the gold and chlorine atoms lie on twofold axes in space group P3121. The packing is largely determined by two hydrogen bonds of the form N–H···Cl, which combine to form chains of rings, the latter with graph set R 4 2 (12). ${\rm{R}}_4^2(12).$ Aurophilic interactions are at best borderline [Au···Au 3.9014(2) Å]. Cyano(methylamine)gold(I), (CH3NH2)AuCN crystallizes in space group P31; the molecules are connected by short aurophilic contacts [Au···Au 3.1507(2) Å] to form spiral chains parallel to the c axis, and also by two hydrogen bonds of the form N–H···N≡C. [ABSTRACT FROM AUTHOR]

The title compound, [CoCd(C9H10NO2)3Cl2]·H2O, is a solvatomorph of the corresponding hemihydrate recently published by us [Nesterova et al. (2018). Appl. Cat. A, 560, 171-184]. The current structure reveals different cell parameters and space group compared with the published one while both are monoclinic with almost the same cell volume. The title compound is formed of discrete neutral dinuclear molecules with no crystallographically imposed symmetry and water molecules of crystallization. The overall geometry about the cobalt(III) ion is octahedral with an N3O3 environment; each ligand acts as a meridional ONO donor. The CdII coordination sphere approximates an irregular square pyramid with a chlorine atom at the apex. There is significant shortening of a Cd-O bond length to the oxygen atom of the methoxo group on one of the ligands [2.459 (3) Å ] compared to the corresponding distance in the published structure [2.724 (7) Å ], while other Cd-Cl/N/O bonds remain roughly the same. In the crystal lattice, the heterometallic molecules, which are related by the crystallographic n-glide plane and interlinked by weak hydrogen bonds to solvent water molecules, form columns along [101]. Adjacent columns lie antiparallel to each other. [ABSTRACT FROM AUTHOR]

Monitoring and control of odorous compound emissions have been enforced by the Korean government since 2005. One of the point sources for these emissions was from food waste composting facilities. In this study, a pilot-scale scrubber installed in a composting facility was evaluated for its performance in the removal of malodorous compounds. The exhaust stream contained ammonia and methylamine as the major odorants detected by the threshold odor test and various instrumental techniques (GC-FID, FPD, MS and HPLC/UV). For the scrubber operation, the column was randomly packed with polypropylene Hi-Rex 200, while aqueous sulfuric acid was selected as the scrubbing solution. To achieve 95% removal, the scrubber must be operated by using H2SO4 solution with pH at < 6.5, liquid to gas ratio > 4.5, gas loading rate < 1750 m3/m3-hr and contact time < 0.94 s. The scrubber performance was further evaluated by determining the mass transfer coefficients and then monitoring for 355 days of operation. The pilot-scale scrubber maintained > 95% ammonia and methylamine removal efficiencies despite the fluctuations in the inlet (from composting facility exhaust stream) concentration. The optimum operating conditions and scrubber performance indicators determined in this study provides a basis for the design of a plant-scale scrubber for treatment of composting facility gas emissions. [ABSTRACT FROM AUTHOR]

The high resolution infrared spectrum of methylamine has been analyzed in the 40–720 cm −1 region (the ν 15  = 2←1 hot and ν 15  = 2←0 overtone bands) with a resolution of 0.00125 cm −1 . More than 14,400 rovibrational transitions (out of 133,000 spectral lines) for 0 ≤  K  ≤ 13 and K  ≤  J  ≤ 40 have been assigned using an original Loomis–Wood program dedicated to methylamine. A global fit of the torsional hot and overtone transitions has been carried out. The assigned transitions were fit to a single state model based on the group theoretical formalism of Hougen and Ohashi, which for the second torsional state seems to be at the limit of applicability. The standard deviation of the fit with K  ≤ 11 and J  ≤ 40 to 94 parameters was 0.006 cm −1 . [ABSTRACT FROM AUTHOR]

Graphical abstract We report that a single water molecule plays a catalytic role in the reaction of dimethylamine with acetaldehyde. Highlights • Dimethylamine is more easily reacted with acetaldehyde than methylamine. • A single water molecule plays an important role in the (CH 3 ) 2 NH + CH 3 CHO reaction. • (CH 3 ) 2 NH + CH 3 CHO + H 2 O should contribute to secondary organic aerosol formation. Abstract We have used quantum chemical methods and transition state theory with Eckart tunneling to study the water-catalyzed addition reaction of dimethylamine ((CH 3 ) 2 NH) and methylamine (CH 3 NH 2 ) with acetaldehyde (CH 3 CHO) responsible for the formation of organic amines acted as the important precursors in the atmospheric nucleation processes. The calculated results show that the CH 3 CHO + (CH 3 ) 2 NH reaction is more feasible than the CH 3 CHO + CH 3 NH 2 reaction because the energy barrier of the CH 3 CHO + (CH 3 ) 2 NH reaction is about 3 kcal/mol lower than that of the CH 3 CHO + CH 3 NH 2 reaction. In addition, a single water molecule can substantially reduce the energy barriers of the CH 3 CHO + (CH 3 ) 2 NH/CH 3 NH 2 reactions. In particular, the reaction barrier of CH 3 CHO + (CH 3 ) 2 NH is decreased from 23.46 to −1.3 kcal/mol with a single water molecule involved. The calculated rate constants also show that the CH 3 CHO + (CH 3 ) 2 NH + H 2 O reaction has strong negative temperature dependence and is about 10 orders of magnitude faster than CH 3 CHO + (CH 3 ) 2 NH. Our results suggest that the CH 3 CHO + (CH 3 ) 2 NH + H 2 O reaction could make a non-negligible contribution to the aerosol nucleation under some atmospheric conditions. [ABSTRACT FROM AUTHOR]

Air pollution by industry and humans activities is a major health issue, notably in major cities. Secondary organic aerosols are formed by oxidation of volatile organic compounds, accounting for 20-80% of organic aerosols in the atmosphere. Secondary organic aerosols are contributing to photochemical smog in urban areas. However, the mechanisms of formation of secondary organic aerosols are still poorly understood. Here, we synthesized secondary organic aerosols by aqueous reaction of hydroxyacetone and methylamine in the dark. Products were analyzed by UV-Vis spectrophotometry and liquid chromatography-mass spectrometry-ion trap-time of flight. Results showed that all reactions fit first-order kinetics, and reactions were accelerated with reactants’ concentrations and pH. The main reaction mechanisms were aldolization of hydroxyacetone, and nucleophilic attack of methylamine to hydroxyacetone, followed by dehydration. The main products were imines, transforming the solution from colorless to deep brown, which is responsible for about 1% of light absorption by atmospheric brown carbon. [ABSTRACT FROM AUTHOR]

New hybrid organic-inorganic derivatives HLnTiO4 · CH3NH2 (Ln = La and Nd) are obtained via the intercalation of methylamine into the interlayer space of protonated layered perovskite-like titanates HLnTiO4. The existence of three stable methylamine derivatives, namely, α-, β-, and γ-forms, is found for each of the titanates. The thermal stability of the obtained intercalation products is studied and their structural parameters are determined. [ABSTRACT FROM AUTHOR]

Particleboard is one of the building materials that contribute to the emittance of formaldehyde in enclosed area. In order to reduce the formaldehyde emission from particleboard, amines were added into the urea formaldehyde (UF) resin as formaldehyde scavenger. The amines used were methylamine, ethylamine and propylamine. 0.5, 0.7 and 1% of each type of amine were added into UF resin and the mixtures were used to produce particleboard from rubberwood particles. The properties of the UF resin after addition of amines such as gelation time, viscosity, pH, free formaldehyde content and thermal stability were evaluated. The physical, mechanical properties and formaldehyde emission of the produced boards were also assessed. The results revealed that fully cured amine-containing UF resin possesses higher thermal stability compared to control UF resin. Amine-containing UF resin also had longer gelation time due to higher pH value. Nevertheless, both physical and mechanical properties of the resultant particleboard were negatively affected. Particleboard made from amine-containing UF resin had higher thickness swelling and water absorption. In addition, lower bending strength and internal bonding strength were also recorded. Insufficient pressing time for fully cured of resin might be the reason for such phenomenon. Particleboard with F*** emission level (0.5 ≤ x ≤ 1.5 mg/L) as specified in Japanese Industrial Standard (JIS) or European's E0 class equivalent were achieved when ethylamine and propylamine were added, regardless of dosage used. This study showed the feasibility of using amines as formaldehyde scavenger. However, optimisation of processing parameters is needed to enhance the physico-mechanical properties of the particleboard. [ABSTRACT FROM AUTHOR]

The effect of methylamine vapor on luminescence of Eu(III) tris-benzoylacetonate ( I ) immobilized in thin-layer chromatography plates has been investigated. It has been revealed that interaction of I with analyte vapor results in increase of the intensity of Eu(III) luminescence. The mechanism of the effect of methylamine vapors on intensification of the Eu(III) luminescence has been suggested using the data of IR spectroscopy and quantum chemistry calculations. The mechanism of luminescence sensitization consists in bonding of an analyte molecule with a water molecule into the coordination sphere of Eu(III). As a result, the bond of a water molecule with the luminescence centre weakens, rigid structural fragment including europium ion, water and methylamine molecules forms. The presence of such fragment must naturally promote decrease of influence of OH-vibrations on luminescence of the complex I . [ABSTRACT FROM AUTHOR]

Reductive functionalization of CO2 with amines and a reductant, which combines both reduction of CO2 and C--N bond formation in one pot to produce versatile chemicals and energy-storage materials such as formamides, aminals, and methylamines that are usually derived from petroleum feedstock, would be appealing and promising. Herein, we give a brief review on recent developments in the titled CO2 chemistry by employing transition-metal-free catalysis, which can be catalogued as below according to the diversified energy content of the products, that is formamides, aminals, and methylamines being consistent with 2-, 4-, and 6-electron reduction of CO2, respectively. Notably, hierarchical reduction of CO2 with amines to afford at least two products, for example, formamides and methylamines, could be realized with the same catalyst through tuning the hydrosilane type, reaction temperature, or CO2 pressure. Finally, the opportunities and challenges of the reductive functionalization of CO2 with amines are also highlighted. 1 Introduction 2 2-Electron Reduction of CO2 to Formamide 3 6-Electron Reduction of CO2 to Methylamine 4 4-Electron Reduction of CO2 to Aminal 5 Hierarchical Reduction of CO2 with Amines 6 Conclusion [ABSTRACT FROM AUTHOR]

The contribution of methanesulfonic acid (MSA) to new particle formation (NPF) has increased significantly with the strict implementation of anthropogenic SO 2 emission reductions globally. However, even considering the enhancing effect of methylamine (MA), identified as the strongest enhancer in MSA-driven NPF, the MSA-driven nucleation rates have been undervalued from the nucleation mechanism of the present theoretical simulation compared to field observations. So, it is vital to evaluate the participation and enhancement of MSA-MA clusters nucleation by the third atmospheric molecule. Herein, the role of trifluoroacetic acid (TFA), which has strong acidity and hydrogen bonding capabilities and is one of the most abundant atmospheric organic substances, has been investigated in the MSA-MA nucleation at different ambient atmospheres by quantum chemical calculations and atmospheric cluster dynamics code (ACDC) simulations. The results indicated that the enhancement strength R of TFA increased with decreasing temperature, up to 7.28-fold at 218.15 K, and is most remarkable in regions with insufficient MSA and relatively larger amounts of TFA and MA. The present results also revealed that TFA plays different roles under different atmospheric conditions. A "catalyst" role of TFA was found in the formation of MSA-MA-based clusters under relatively low temperatures (such as during winter or the top of troposphere at higher altitudes) and medium concentrations of TFA and MA. Whereas in the vicinity of major sources of TFA and MA emission (with the highest [TFA] and [MA]), TFA acted as a "direct participant" in the formation of nucleus clusters during winter or the top of troposphere (218.15 K). These new insights may be useful in understanding the perspective of the realistic role of TFA in MSA-MA-driven NPF, especially in the intensive human activity and industrial pollution serious of global megacities with winter of dry climate, or western China, Africa and the Arctic remote regions with scant precipitation and the abundant TFA pollutants sources. • TFA can enhance the formation rates of MSA-MA-based clusters at lower T and [MSA] as well as higher [TFA] and [MA]. • TFA can act as both a "catalyst" and a "participator" in the growth of MSA-MA clusters. • TFA is critical for NPF in the region of insufficient MSA and relatively larger amounts of TFA and MA. • This work reveals the realistic role of TFA in MSA-MA-driven NPF, especially in remote regions with scant precipitation. [ABSTRACT FROM AUTHOR]

The present study measured the concentrations of aliphatic amines (methylamine (MA), ethylamine (EA), dimethylamine (DMA), diethylamine (DEA), trimethylamine (TMA), and triethylamine (TEA)) in both the aerosols and gas phase at a forested site in Japan, and discussed their seasonal trends and potential sources. These measured amines were more preferentially partitioned into the aerosols than into the gas phase, and mainly distributed into the fine-mode range in the aerosols, although the DMA and TMA were also abundant in the gas phase and the TMA in the aerosols was mainly distributed into the coarse-mode range. The most abundant amine both in the aerosol and gas phase was the DMA, followed by the MA. The MA, EA, DMA, and DEA in the gas phase and aerosols showed higher concentrations in the summer, although the coarse-mode EA concentration did not show the seasonality. The gaseous TMA also showed higher concentrations in the summer, but the coarse-mode TMA increased in the autumn and no seasonality was found in the fine-mode TMA concentrations. The TEA in the gas phase showed higher concentrations in the autumn, but that in the aerosols did not show the seasonality. The decomposition of organic materials in the soil and subsequent volatilization would be an important source of the gaseous MA, DMA, DEA, and TMA. Various biogenic activities can be also expected to be potential sources of the gaseous MA and DMA. The fine-mode MA, EA, DMA, DEA, TMA, and the coarse-mode DMA would be derived from their gaseous form through direct dissolution. Some portions of the fine-mode MA, DMA, and the coarse-mode DMA can be expected to be derived from the primary sources such as biogenic particles like plant debris. The transport of the anthropogenic aerosols can be also expected to contribute to the fine-mode MA. Only the TEA in the gas phase was suggested to be derived from the different sources in the forest from the other five gaseous amines and not contribute to the formation of the fine-mode TEA. It can be considered that the coarse-mode MA, EA, DEA, TMA, TEA, and the fine-mode TEA were affected by the sources independent from the local emission of the gaseous amines, such as the primary sources or the transport from distant sources, although some portions of the coarse-mode MA, EA and DEA might be derived from the dissolution of their gaseous form. Biogenic and pedospheric processes in the forest would be important sources for the amines, especially the gaseous and fine-mode amines, in a forest atmosphere. • The measured six amines were mainly distributed into the fine-mode aerosols. • The most abundant amine in the aerosol and gas phase was the DMA, followed by the MA. • Many of the gaseous and particulate amines showed high concentrations in the summer. • Decomposition of organic matters in the soil was a main source of the gaseous amines. • The fine-mode amines were mainly caused by the gas phase through direct dissolution. [ABSTRACT FROM AUTHOR]