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Copper nanowires were synthesized by the wet chemical reduction method using copper sulfate as the copper precursor, aliphatic amines (methylamine, ethanediamine, 1,2-propanediamine) as the inducing reagents, and hydrazine hydrate as the reductant through the aging and reduction processes. The high-resolution transmission electron microscopy (HRTEM) images reveal that the copper nanowires were synthesized by coalescing extremely small-sized copper nanoparticles with the particle sizes of 1–6 nm in copper complex micelles. A longer aging time period favored the coalescing of the copper nanoparticles to form thinner copper nanowires in the following reduction process. The coalescing extent of copper nanoparticles in copper nanowires was highly enhanced by ethanediamine and 1,2-propanediamine as compared with that by methylamine. The copper nanowire-filled polyester films had higher electrical conductivity than the copper nanoparticle-filled ones.

New methylamine derivatives with 1,2-azole fragments (phenylisoxazole, p-tolylisoxazole, 2,5-dimethylphenylisoxazole and 4,5-dichloroisothiazole) and their palladium complexes were synthesized. It was shown that palladium complexes with the obtained N-methyl-1-(1,2-azol-3-yl)methylamine exhibit high catalytic activity in the Suzuki reaction in aqueous medium.

The fast progress of lab-scale perovskite solar cells makes the problem of upscaling of perovskite thin-film deposition more and more acute; therefore, the development of new methods for perovskite deposition is highly desired. In this work, we proposed a new solution-free preparation approach for hybrid perovskite films based on the in situ generation of methylammonium iodide from methylamine and iodine vapors in the presence of an organic reducing agent conjugated with a redox process of metallic lead conversion with iodine vapor. At first, we demonstrated that either metallic lead or lead iodide powders can readily react with the solution of methylamine and iodine in the presence of isopropyl alcohol acting as a reducing agent, resulting in a phase-pure polycrystalline CH3NH3PbI3 perovskite. A possible mechanism of underlying chemical processes has been proposed. In order to convert the predeposited thin films of metallic lead to CH3NH3PbI3 perovskite, a protocol of sequential treatment by iodine and methylamine vapors was proposed. Finally, we revealed the optimal conditions of processing, which were proven to be facile and robust for the sake of the better control of perovskite grain morphology.

The electrochemical reduction of carbon dioxide is an appealing technology that stores renewable electricity in the chemical form and has the potential to transform the way carbon fuels are utilized today. While there have been successes in the electrosynthesis of alkanes, alkenes and alcohols, access to organonitrogen molecules such as alkylamines remains largely beyond the reach of current electrocatalysis. Here we report the first electrochemical reaction that converts carbon dioxide and nitrate to methylamine in aqueous media under ambient conditions catalysed by a cobalt β-tetraaminophthalocyanine molecular catalyst supported on carbon nanotubes. The overall reaction, involving the transfer of 14 electrons and 15 protons to form each methylamine molecule, is an eight-step catalytic cascade process enabled by the coupling of two reactive intermediates near the catalyst surface. The key C–N bond-forming step is found to be the spillover of hydroxylamine from nitrate reduction and its subsequent condensation with formaldehyde from carbon dioxide reduction. This study provides a successful example of sustainable alkylamine synthesis from inorganic carbon and nitrogen wastes, which could contribute to greenhouse gas mitigation for a carbon-neutral future. The electroreduction of CO2 provides a sustainable pathway to value-added fuels and chemicals. Here the authors show a cascade reaction that yields methylamine from CO2 and nitrate. With detailed insight into the multistep catalytic process, the current findings further push the boundaries of this technology.

The dependence of the global population on ammonia means that the Haber–Bosch process is one of the most studied and optimised processes in chemistry. Despite this focus, the reaction still requires harsh conditions, which has prompted substantial research efforts to enable the electroreduction of N2 at ambient conditions. The literature regarding this reaction is plagued with reports of competition with the hydrogen evolution reaction and large potentials required for N2 dissociation. Cyanide, isoelectronic with N2, has a significantly lower bond dissociation energy which could enable a route to sustainable ammonia production. Herein, we present the first mechanistic study of the cyanide electroreduction on a Ni cathode, experimentally shown to produce methylamine as a major product, and CH4 and NH3 as minor products. Theoretical calculations reveal that the dominance of methylamine in the products is due to the weak binding of this species, which desorbs from the surface preventing further hydrogenation. We also present an alternative CNRR pathway which involves the hydrogen atoms comprising the predicted surface coverage at relevant reaction conditions. Interestingly, this new pathway circumvents the formation of methylamine, exclusively producing CH4 and NH3, although it is hindered by the presence of a large energy barrier. Strategies to favour this alternative pathway and the prospects of CNRR for the sustainable production of ammonia under ambient conditions are also outlined.

The reaction of 4-X-substituted 1-[(difluoromethyl)sulfinyl]-2,3,5,6-tetrafluorobenzenes (X = CF3, H, OMe) with methylamine and ammonia in MeCN, Et2O, and hydrocarbons occurs involves nucleophilic substitution in position 2 of the substrate. The reaction time increases with increasing donor ability of substituent X in the series X = CF3 < H < OMe, as well as with decreasing solvent polarity. Further substitution of fluorine in position 6 of the substrate by methylamine is also possible, but requires a higher reaction temperature. The reaction of ammonia with 1-[(difluoromethyl)sulfinyl]-4-methoxy-2,3,5,6-tetrafluorobenzene is accompanied by partial demethylation to form 2-[(difluoromethyl)sulfinyl]-3,4,6-trifluoro-5-methoxy-N-methylaniline and 4-[(difluoromethyl)sulfinyl]-2,3,5,6-tetrafluorophenol.

A method for preparing fully brominated sulfonium derivatives of the closo-decaborate anion with functional amino groups (n-Bu4N)[2-B10Br9S((CH2)nNH2)2]– (n = 1–3) has been developed. The method is based on the interaction between sulfonium derivatives of the closo-decaborate anion with phthalimide groups (n-Bu4N)[2-B10Br9S((CH2)npht)2]– (n = 1–3) and elemental bromine in acetonitrile in an inert atmosphere, followed by removal of the phthalimide protection using methylamine.

The electrochemical performance of two Na2/3Ni1/3Mn2/3O2 samples, prepared by an oleic - assisted emulsion procedure, is examined. As a novelty, the effect of cosurfactants with either short (methylamine) or long (octylamine) chains is determined for their applicability as cathode materials for sodium-ion batteries. Their structural and morphological properties are studied by X-ray diffraction and electron microscopy. The electrochemical performance is determined by cycling sodium half cells by the galvanostatic method. Especial interest is devoted to their kinetic properties evaluated by impedance spectroscopy

BACKGROUND: Persimmon tannin, extracted from young astringent persimmons, is a cheap waste biomass material. The abundant phenolic hydroxyl groups in persimmon tannin are known to display excellent affinity to Mo(VI). In addition, ligands containing N donor atoms, as brilliant adsorption groups, can strongly interact with Mo(VI) when the groups are protonated under acidic conditions. Therefore, the introduction of nitrogen‐containing groups in persimmon tannin may be an effective method to improve the recovery capacity of biosorbent for Mo(VI) in aqueous solution. In this work, a series of adsorbents were prepared by immobilizing ethylenediamine or methylamine on the surface of persimmon tannin. RESULTS: Due to the abundant nitrogen‐containing groups and hydroxyl groups, the ethylenediamine modified persimmon tannin exhibited excellent maximum uptake capacity to Mo(VI) (478.02 mg·g⁻¹), which was superior to that of methylamine modified persimmon tannin. Further, the results of XPS and FT‐IR confirmed that Mo(VI) was adsorbed on the hydroxyl‐assisted nitrogen‐containing group modified persimmon tannin via coordination and electrostatic interaction. CONCLUSION: Furthermore, 99% of Mo(VI) was selectively recovered from coexisting ions by en‐CPT under appropriate acidic conditions (pH 1). Pseudo‐second‐order kinetic model best represented the adsorption process of Mo(VI) onto the en‐CPT. The adsorption equilibrium was achieved in a relatively short time (no more than 1 h). High recovery efficiency and excellent selective adsorption made the en‐CPT an ideal candidate for Mo(VI) recovery in practical applications. © 2020 Society of Chemical Industry (SCI)

PTDC/NAN-MAT/30565/2017 D01-284/2019 (INFRAMAT) IBB BASE 2020-2023 UID/FIS/00068/2019. The ability to change the secondary electron emission properties of nitrogen-doped graphene (N-graphene) has been demonstrated. To this end, a novel microwave plasma-enabled scalable route for continuous and controllable fabrication of free-standing N-graphene sheets was developed. High-quality N-graphene with prescribed structural qualities was produced at a rate of 0.5 mg/min by tailoring the high energy density plasma environment. Up to 8% of nitrogen doping levels were achieved while keeping the oxygen content at residual amounts ( 1%). The synthesis is accomplished via a single step, at atmospheric conditions, using ethanol/methane and ammonia/methylamine as carbon and nitrogen precursors. The type and level of doping is affected by the position where the N-precursor is injected in the plasma environment and by the type of precursors used. Importantly, N atoms incorporated predominantly in pyridinic/pyrrolic functional groups alter the performance of the collective electronic oscillations, i.e. plasmons, of graphene. For the first time it has been demonstrated that the synergistic effect between the electronic structure changes and the reduction of graphene $-plasmons caused by N doping, along with the peculiar “crumpled” morphology, leads to sub-unitary (textless 1) secondary electron yields. N-graphene can be considered as a prospective low secondary electron emission and plasmonic material. publishersversion published

Reactions of photochemical hydrogen transfer are modeled by means of quantum chemistry. Nitromethane and nitrobenzene in the triplet state in combination with ammonia, methylamine, or dimethylamine as hydrogen donors are studied. The structures of reaction complexes of the original materials, the transitional states and reaction products, the activation energies of the reactions, and changes in the standard enthalpies of the reactions are determined. The profiles of the potential energy surfaces of certain reactions are modeled. It is established that all profiles are very smooth, and the activation energies are low. The distribution of electron density in complexes is studied using Bader’s theory of atoms in molecules. All complexes have a characteristic ring structure that can be considered a source of additional interaction during a reaction. It is suggested that such a structure is responsible for the low activation energies of the reaction.

The new copper(II) complex [CuLCl2]2, where L is a product of Schiff base condensation between methyl­amine and 2-pyridine­carbaldehyde, is built of discrete centrosymmetric dimers., The new copper(II) complex, namely, di-μ-chlorido-bis­{chlorido­[meth­yl(pyri­din-2-yl­methyl­idene)amine-κ2 N,N′]copper(II)}, [Cu2Cl4(C7H8N2)2], (I), with the ligand 2-pyridyl­methyl-N-methyl­imine (L, a product of Schiff base condensation between methyl­amine and 2-pyridine­carbaldehyde) is built of discrete centrosymmetric dimers. The coordination about the CuII ion can be described as distorted square pyramidal. The base of the pyramid consists of two nitro­gen atoms from the bidentate chelate L [Cu—N = 2.0241 (9), 2.0374 (8) Å] and two chlorine atoms [Cu—Cl = 2.2500 (3), 2.2835 (3) Å]. The apical position is occupied by another Cl atom with the apical bond being significantly elongated at 2.6112 (3) Å. The trans angles of the base are 155.16 (3) and 173.79 (2)°. The Cu⋯Cu separation in the dimer is 3.4346 (3) Å. In the crystal structure, the loosely packed dimers are arranged in stacks propagating along the a axis. The X-band polycrystalline 77 K EPR spectrum of (I) demonstrates a typical axial pattern characteristic of mononuclear CuII complexes. Compound (I) is redox active and shows a cyclic voltammetric response with E 1/2 = −0.037 V versus silver–silver chloride electrode (SSCE) assignable to the reduction peak of CuII/CuI in methanol as solvent.

The scientific interest in catalytic hydroaminoalkylation reactions of alkenes has vastly increased over the past decade, but these reactions have struggled to become a viable option for general laboratory or industrial use because of reaction times of several days. The titanium‐based catalytic system introduced in this work not only reduces the reaction time by several orders of magnitude, into the range of minutes, but the catalyst is also demonstrated to be easily available from common starting materials, at a cost of approximately 1 € per millimole of catalyst. We were also able to formally perform C−H activation of methylamine and achieve coupling to a broad variety of alkenes, through silyl protection of the amine and simple deprotection by water., Methylamine can be coupled to alkenes by using a titanium hydroaminoalkylation catalyst that is inexpensive (1 €/g) and easily accessible. Compatibility of methylamine with the catalyst is achieved by silylation; the products can be isolated with the protective group intact or, through simple deprotection with water, as the free amine.

Solvated sodium anions (Na-) were thought to behave essentially like isolated gas-phase ions that interact only weakly with their environments. For example, 23Na NMR signals for solvated Na- are very sharp, despite the potential for strong quadrupolar broadening. The sharp NMR signals appear to indicate a nearly spherical electron density of the ion. For the present study, ab initio molecular dynamics simulations and quadrupolar relaxation rate calculations were carried out for the Na-/Na+ [2.2.2]cryptand system solvated in methylamine, followed by detailed analyses of the electric field gradient at the sodium nuclei. It is found that Na- does not behave like a quasi-free ion interacting only weakly with its environment. Rather, the filled 3s shell of Na- interacts weakly with the ion's own core and the nucleus, causing Na- to appear in NMR experiments like a free ion.

In the present study, the first ever and easy surfactant-aided synthesis of hexadecyltrimethyl ammoniumbromide-stabilized RhCo nanoclusters (Rh0.63Co0.37@CTAB) and their employment as highly efficient,relatively cost-saving, and recyclable catalysts to generate hydrogen from the hydrolysis reactions ofmethylamine borane (MeAB) and dimethylamine borane (DMAB) are reported. The easy synthesis of Rh0.63-Co0.37@CTAB nanoclusters is accomplished by synchronous reduction of appropriate rhodium and cobaltsalts by sodium borohydride in the presence of CTAB as a surfactant in aqueous solution at roomtemperature. The Rh0.63Co0.37@CTAB nanoclusters are characterized by some techniques like ultravioletvisibleelectronic absorption spectroscopy (UV-vis), transmission electron microscopy (TEM), and X-rayphotoelectron spectroscopy (XPS). They provide very remarkable turnover frequencies (TOFs) of 107.1min−1 and 142.9 min−1 (8571.4 h−1, best ever value) in the hydrolysis of MeAB and DMAB, respectively, evenat very low temperatures. Their activation energies in the same reactions are calculated to be 55.3 kJ mol−1and 50.3 kJ mol−1, respectively.

Although some thermoanalytical studies regarding thermal analysis of dipyrone sodium monohydrate had already been presented in literature, results are incomplete once no evolved gas analysis has been presented. In addition, the inorganic residue should also be better characterized regarding the presence of sodium sulfate or sodium hydrogen sulfite, once the amount of residue varies depending on experimental conditions. In this work, the thermal degradation of dipyrone sodium monohydrate was revisited regarding evolved gases, intermediates produced during heating and inorganic residue. Thus, dipyrone sodium monohydrate was analyzed using TG/DTG/DTA, DSC, hot-stage microscopy, TG–FTIR and HPLC–MS looking for proposing a thermal behavior mechanism for this important pharmaceutical. Moreover, inorganic residue was investigated by XRD and FTIR. The evolved gases were detected and identified in the following sequence: water, sulfur dioxide, methylamine, isocyanic acid, benzene, ammonia and carbon dioxide. Regarding the inorganic fraction, intermediates were collected at 500 and 1000 °C and characterized as Na2SO4 in dry air atmosphere. From these data obtained by combining results from thermoanalytical techniques with those from HPLC–MS, FTIR and XRD, a mechanism for the thermal behavior of dipyrone sodium monohydrate was proposed.

A new catalyst was prepared using sulfonated reduced graphene oxide support with a large surface area containing ruthenium nanoparticles (Ru@rGO-SO3H). The developed Ru@rGO-SO3H catalyst was used in the hydrogen production process from the hydrolytic dehydrogenation of methylamine-borane (MeAB). Sulfonated reduced graphene oxide and the developed catalyst were characterized by Raman and FT-IR spectroscopies, ICP-OES, XRD, XPS, TEM, TEM-EDX, SEM and SEM-EDX techniques. The average particle size of Ru nano particles, which were homogeneously distributed on the sulfonated reduced graphene oxide surface, was found as 2.2 +/- 0.2 nm. After analyzing the effect of nanocatalyst and substrate concentrations on the catalytic reaction, reactions were realized at different temperatures, the efficiency of the Ru@rGO-SO3H nanocatalyst in initial turnover frequency (TOFinitial) and the activation parameters (E-a, Delta H-# and Delta S-#) were calculated. According to the data obtained, the TOFinitial value was calculated as 5300.86 h(-1) (88.35 min(-1)). E-a, Delta H-# and Delta S-# values were also calculated as 53.83 kJ/mol, 50.73 kJ/mol and -51.55 J/mol.K, respectively. Finally, when the reusability performance results of the catalyst are evaluated, it is found that the catalyst is very stable and retains its initial effectiveness to a great extent (>95%) after the 5th reuse. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Amongst different amine-borane derivatives, methylamine-borane (CH3NH2BH3) seems to be one of the capable aspirants in the storing of hydrogen attributable to its high hydrogen capacity, stability and aptitude to generate hydrogen through its catalytic hydrolysis reaction under ambient conditions. In this research paper, we report that cobalt nano-particles supported on alumina nanofibers (Co/Al2O3) are acting as active nanocatalyst for catalytic hydrolysis of methylamine-borane. Co/Al2O3 nanocatalyst was fabricated by double-solvent method followed with wet-chemical reduction, and was characterized by utilizing various spectroscopic methods and imaging techniques. The results gathered from these analyses showed that the formation Al2O3 nanofibers supported cobalt(0) nanoparticles with a mean diameter of 3.9 +/- 1.2 nm. The catalytic feat of these cobalt nanoparticles was scrutinized in the catalytic hydrolysis of methylamine-borane by considering their activity and durability performances. They achieve releasing of 3.0 equivalent of H-2 via methylamine-borane hydrolysis at room temperature (initial TOF = 297 mol H-2/mol metal x h). Along with activity the catalytic durability of Co/Al2O3 was also studied by carrying out recyclability tests and it was found that these supported cobalt nanoparticles have good durability during the course of the catalytic recycles so that Co/Al2O3 preserves almost its innate activity at 5th catalytic recycle. The studies presented here also contains kinetic investigation of Co/Al2O3 catalyzed methylamine borane hydrolysis depending on the temperature, cobalt and methylamine borane concentrations, which were used to define rate expression and the activation energy of the catalytic reaction. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Coordination complexes have emerged as prominent modulators of amyloid aggregation via their interaction with the N-terminal histidine residues of amyloid-β (Aβ). Herein, we report the synthesis and characterization of a novel cobalt(III) Schiff base complex with methylamine axial ligands, and we present both computational and experimental data demonstrating the reduction of β-sheet formation by this complex. The computations include molecular dynamics simulations of both monomeric and pentameric Aβ, which demonstrate decreased formation of β-sheet structures, destabilization of preformed β-sheets, and suppression of aggregation. These results are consistent with a dose dependence in experimental bulk aggregation data using thioflavin T fluorescence, and overall this study demonstrates useful drug activity of the cobalt complex.

Several metal nanoparticle based catalysts have been synthesized for catalyzing the hydrogen production process by hydrolysis of methylamine-borane (MeAB). However, there was only one study that catalyzes the producing of hydrogen via the methanolysis of MeAB, and it was carried out by our research group. For this reason, in this work, a new catalyst system entitled by single-walled carbon nanotube (SWCNT) supported bimetallic platinum-ruthenium nanoparticles were developed and called as PtRu@SWCNT. These NPs were characterized by several techniques (XRD, XPS, Raman, and TEM), and they were performed for the methanolysis of MeAB with high catalytic activity. The prepared PtRu@SWCNT NPs were also tested in the methanolysis of MeAB at different parameters including different temperatures, catalyst and substrate concentrations, and reusability performance. Experimental results revealed that the new PtRu@SWCNT NPs had excellent catalytic activity and reusability for removing of hydrogen from the methanolysis of MeAB at ambient conditions. According to the obtained data, the turnover frequency is 136.25 mole H2/mole PtRu × min, and the activation energy (Ea) is 17.29 kJ/mole. More than 99% of conversion was observed at room temperature. © 2019, The Author(s)., Kütahya Dumlupınar Üniversitesi, The authors would like to thank Van Yuzuncu Yil (FAP-2018-7373) and Dumlupinar University for funding.

Organic amines, including amine groups and carbon groups, are highly toxic chemicals with regard to both human health and ecosystems. However, the treatment of organic amines in wastewater remains a challenge using existing methods because of poisonousness of amines to microorganisms and simultaneous poor denitrification. In this work, we used a photoelectrochemical-chlorine radicals process to selectively and efficiently degrade organic amines into N2 and CO2. The proposed process was based on the reaction of organic amines with chlorine radicals (Cl ) and hydroxyl radicals (HO ) and a fast reduction reaction of nitrate-N on a porous Pd-Cu/porous nickel cathode (Pd-Cu/PN). For dimethylamine (DMA), this system achieved removal rates of 99.20% and 51.34% for total nitrogen (TN) and total organic carbon (TOC) within 2.5 h, respectively. Four main intermediate products, including methylamine (MA), ammonia (NH4+), nitrate (NO3−) and nitrite (NO2−), were observed, and no chlorohydrocarbon was detected. The analysis of electron-spin resonance (ESR) and a free-radical capture experiment confirmed that free radicals, especially Cl , played an important role in the denitrification of DMA. Trimethylamine (TMA), ethylamine (EA) and diethylamine (DEA) were also degraded to demonstrate the general applicability of this system, and the corresponding TN removal rates were 96.23%, 93.85% and 92.37%, respectively. This work provides a new, efficient, highly selective and environmentally friendly treatment method for removing organic amines from wastewater.

A tridentate N,N,S-donor ligand, 2-benzoylpyridine-N(4),N(4)-(N,N-diethyl-N-methylamine-2,2'-diyl)thiosemicarbazone (Hbptsc) has been synthesized and characterized by elemental CHN analysis, UV-visible, FT-IR and 1H NMR spectroscopy. Copper(II) complexes of the ligand, Hbptsc synthesized have been characterized by elemental analysis, UV-visible spectra, FTIR spectra and EPR spectroscopic simulation. The complexes hold the stoichiometry of the type [CuLX] where X= Cl (1), NO3 (2), SO4 (3), N3 (4), SCN (5) confirmed by the molar conductivity studies of 10-3 M solutions in DMF at room temperature. The EPR spectra of the complexes recorded in DMF at 77 K shows an axial type spectra with two distinct g-values, g|| and g⊥ indicating a four coordinated planar geometry. The antimicrobial studies of the copper(II) complexes shows an appreciable activity against both gram positive and gram negative bacteria using streptomycin as positive control. The short term in vitro cytotoxicity studies following trypan blue dye exclusion method exhibits pronounced activity against the Dalton’s Lymphoma Ascites tumour cells extruded from the peritoneal cavity of mice.

The pH of spray mixtures is an important attribute that affects dicamba volatility under field conditions. This report examined the effect of different components added to water sources that ranged in initial pH from 4.6 to 8.4. Commercial products were used, which include formulations of dicamba, glyphosate, the drift retardant Intact, ammonium sulfate (AMS), and several pH modifiers. Adding BAPMA salt of dicamba always increased the mixture pH, whereas diglycolamine + VaporGrip® (DGA+VG) had a mixed response. The addition of AMS decreased pH slightly (usually

International audience; Hydrazine-boranes (HNNH·BH and HB·NHNH·BH) have been proposed for the storage of hydrogen, but these compounds have not created scope for extensive research works as ammonia- and methylamine-boranes have made these last decades. In the exciting research devoted to energy storage with environmentally friendly processes, hydrazine-borane, hydrazine-bisborane, and their simply substituted derivatives could provide a satisfactory response for hydrogen production and recyclability of the formed products. To date, knowledge of the physical and chemical properties of these compounds is still scarce. In this paper, the electronic structure of various hydrazine-boranes complexes is studied by ultraviolet-photoelectron spectroscopy (UV-PES), which is the experimental technique giving direct access to the energy of occupied molecular orbitals. Thus, UV-PE spectra were registered and first ionization energies were determined. Understanding of different types of interactions between nitrogen lone pairs and their variations by complexation has been our essential goal in these studies. In particular, clear stabilization of all molecular orbital energies is noted when complexation with borane takes place. Evolution of the σ bond during the hydrogen release process upon thermal activation has also been studied experimentally by UV-PES and supported by quantum chemical calculations.

The atmospheric oxidation of amines proceeds via initial radical attack at C–H or N–H bonds to form carbon‐ and nitrogen‐centered radicals, respectively. It is conventionally assumed that nitrogen‐centered aminyl radicals react slowly with oxygen in the troposphere and associate predominantly with the radicals •NO and NO2• to form toxic nitrosamines and nitramines. We have used theoretical kinetic modeling techniques to study the prototypical CH3N•H + O2 reaction and have shown that it proceeds to CH2NH + HO2• under tropospheric conditions with a rate coefficient of 3.6 × 10−17 cm3 molecule−1 s−1. Although this value is low compared to the competing NOx reactions (∼10−11 cm3 molecule−1 s−1), the much higher concentration of O2 versus NOx in air makes it the dominant process in the atmospheric oxidation of methylamine for NOx concentrations below 100 ppb. The mechanism identified here is available to amines with primary, secondary, and tertiary α carbons and suggests that they may be less likely to form nitramines and nitrosamines than is currently thought.

Two new tridentate SNS ligands based on a flexible, straight chain amine backbone were prepared and in combination with three related but previously reported ligands were reacted with CuCl2 to yield new tridentate pincer-type copper(II) complexes. The molecular structures of the new ligands bis(cyclohexylthioethyl)methylamine (L1d), bis(t-butylthioethyl)methylamine (L1e), and all the complexes Cu[bis(Rthioethyl)methylamine]Cl2 (1) where R = methyl (a); ethyl (b); butyl (c); cyclohexyl (d) and t-butyl (e); were confirmed by a range of spectroscopic and analytical techniques. Single crystal X-ray diffraction analysis determined the solid-state structures of the salt of L1e and the complexes. Complexes 1a-e all exhibited five-coordinate ligand geometry around each Cu(II) centre defined by the tridentate SNS and two chlorido donors. The complexes were applied as catalysts in the oxidation of n-octane using t-butyl hydroperoxide and hydrogen peroxide (H2O2) as oxidants. The H2O2 based systems yielded up to 36% conversion of n-octane to C-8 oxygenates with very high alcohol selectivity of up to 78%.

Different coordination modes of the same Schiff base ligand enable formation of the dimeric NiII complex. The phenolato-bridged metal centres are further apart in the Ni dimer compared to the isomorphous Cu compound., 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 ▸). Acta Cryst. E69, m551–m552]. In the crystal, the [Ni2 L 4] 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.

Methylamine (MA) is highly toxic even at low concentrations. The current U.S.A. Occupational Safety and Health Administration Permissible Exposure Limit (OSHA PEL) is 10 ppm in the gas phase. In this study we have developed low-cost, robust and stable copper sulphide film on flexible plastic and paper substrate. The sensitivity of the film towards MA as a function of print density is studied at room temperature. The electrical and colorimetric response of the sensing films is optimized with respect to print density. The performance parameters of the sensing films including, sensitivity, a lower limit of detection (LOD), selectivity and onset time of detection are determined. X-ray photoelectron spectroscopy is employed for chemical characterization of the sensing film. It is demonstrated that copper sulphide films register either change in resistance or colour when exposed to methylamine in a range of 1 to 100 ppm. A LOD of 1 ppm is achieved which is lower than the current OSHA PEL. The optimized sensing film has shown over three and six orders of magnitude change in resistance when exposed to 10 ppm and 500 ppm of MA respectively. The low cost, room temperature operation, electrical and colorimetric response of the developed sensing films make them promising candidates to be used for medical diagnostics as well as industrial use for example in chemical industry and environmental applications.

Bismuth halide perovskites are potential lead-free absorbing materials for solar cells. However, methylamine and cesium-based bismuth perovskites are insufficient for visible light absorption because of their large bandgaps. In this work, we developed a new formamidinium (FA)-based bismuth perovskite material, (FA)3Bi2I9. (FA)3Bi2I9 shows a hexagonal phase with an enlarged unit cell than the conventional methylamine-based bismuth perovskite (MA)3Bi2I9. It has a bandgap of 2.19 eV and a Wannier–Mott exciton binding energy of 260 meV, which are lower than those of (MA)3Bi2I9 (2.25 eV and 320 meV, respectively) in our experiments. Thus, (FA)3Bi2I9 is more suitable as an absorbing layer for solar cells than (MA)3Bi2I9. In addition, solvents can effectively control the growth of (FA)3Bi2I9 films. In specific, using dimethyl sulfoxide as the solvent resulted in enhanced c-axis oriented growth and plate-like microstructure. With these bismuth perovskite films as absorbing layers, mesoporous-structured (FA)3Bi2I9 solar cells were fabricated for the first time. The initial devices show the highest open voltage of 0.48 V and a power conversion efficiency of 0.022%, which are higher than those of methylamine-based bismuth perovskite solar cells, offering a potential candidate for lead-free perovskite solar cells.

Tow new α-aminophosphonic acids, Ethyl hydrogen [(2-methoxyphenyl)(methylamino) methyl]phosphonate (2-EHMAP) and Ethyl hydrogen [(3-methoxyphenyl)(methylamino) methyl]phosphonate (3-EHMAP) were synthesized by the reaction between Methylamine, 2- or 3-Methoxybenzaldehyde and Diethylphosphite in THF solution with FeCl3. The structures of the title compounds were determined by UV–Vis, FT-IR, 1H, 13C, 31P NMR and MS spectra and confirmed by centesimal analysis. Their inhibition efficiency on the corrosion of mild steel in 1 M HCl and 0.5 M H2SO4 solutions was studied by weight loss, polarization curves and electrochemical impedance spectroscopy (EIS). The surface morphology of XC38 simple was studied by scanning electron microscopy (SEM) and Atomic Force Microscopy (AFM). The experimental results show that both molecules are mixed inhibitors and that their adsorptions on the surface of mild steel obey the Langmuir isotherm and that the 2-EHMAP exhibit better inhibition efficiency. Quantum chemical calculations were performed by using DFT to study the influence of molecular structure on the inhibition efficiency; theoretical findings are in good accord with the experimental observations.

Water-soluble organic nitrogen (WSON) in fine particulate matter (PM2.5) was determined at urban coastal environments in China based on 1-year measurement. The WSON concentrations were in a range of 14.3–257.6 nmol N m−3 and accounted for 22.0–61.2% of the water-soluble nitrogen (WSN) in composition. The average total concentration of free amino acid (FAA) was 1264.5 ± 393.0 pmol m−3, which was lower than those in continental urban cities but nevertheless comparable to the rural area of Pearl River Delta (PRD) in China. The total quantified amines and amino compounds ranged from 223.8 to 806.0 pmol m−3 in which methylamine, ethylamine, and ethanolamine were the most abundant compounds. The average concentration of urea was 7.8 ± 3.0 nmol m−3 and at least one order of magnitude higher than those in marine and rural areas but comparable to other continental cities in China during non-dust period. Summer showed the highest average concentration of WSON (95.0 ± 66.6 nmol N m−3) and composition in WSN (49.3%) compared to other seasons (27.9–37.0%). The results were consistent with previous findings that the inorganics can contribute more than the organics in secondary aerosol formation. There were no distinctive seasonal variations of organic compositions of FAA, amine and amino compounds, and urea. This observation was possibly attributed to a mix of original sources in urban and different prevailing wind directions. Fair correlations (r

Amines play an important role in the formation and transformation of atmospheric aerosols. Gaseous phase and PM2.5 samples were collected simultaneously at Nanling Mountains, southern China during autumn 2016 and summer 2017. The site is strongly affected by long distance transport from marine and continental air masses. Five amines, methylamine (MA), dimethylamine (DMA), diethylamine (DEA), dibutylamine (DBA) and morpholine (MOR), were detected by gas chromatography-mass spectrometry (GC-MS) after derivatization. The backward trajectory analyses suggested that different origins of air masses led to seasonal variation of amines. In gaseous phase samples, the average concentrations of total measured amines (Ʃamines) were 193.4 ± 111.7 ng m−3 in autumn 2016 and 307.5 ± 196.7 ng m−3 in summer 2017. In PM2.5 samples, the average concentrations of Ʃamines were 12.4 ± 10.8 ng m−3 in autumn 2016 and 20.7 ± 11.0 ng m−3 in summer 2017. MA and DMA were the dominant amines, together contributing approximately 70% to gaseous amines and 80% to particulate amines. A strong linear relationship was found between Ʃamines and NO3− in PM2.5, implying that amines might mainly exist in the form of aminium nitrate. Ammonium (NH4+) was found mostly likely in the form of ammonia sulfate. Approximately 7.4% of the gaseous total amines partitioned to PM2.5. A good linear relationship between the fraction of total atmospheric concentration sorbed by PM2.5 (Φ) and the concentrations of O3 was found, suggesting that O3 likely played an important factor in the gas-to-particle partitioning of amines. Additionally, under high relative humidity circumstances (92% ± 7.0%), direct dissolution was a crucial step for gaseous amines partitioning into particles. The ratios of amines-C to water-soluble organic carbon (WSOC) and amines-N to water-soluble organic nitrogen (WSON) were 0.21% and 1.57% in autumn 2016 and 0.54% and 2.08% in summer 2017, respectively. The results of this study provide essential information on the formation mechanism of particulate amines.

A new two-dimensional (2D) coordination polymer of the formula {Cu(ox)(4-Hmpz)·1/3H2O}n (1) (ox = oxalate and 4-Hmpz = 4-methyl-1H-pyrazole) has been prepared, and its structure has been determined by single-crystal X-ray diffraction. It consists of corrugated oxalato-bridged copper(II) neutral layers featuring two alternating bridging modes of the oxalate group within each layer, the symmetric bis-bidentate (μ-κ2O1,O2:κ2O2′,O1′) and the asymmetric bis(bidentate/monodentate) (μ4-κO1:κ2O1,O2:κO2′:κ2O2′,O1′) coordination modes. The three crystallographically independent six-coordinate copper(II) ions that occur in 1 have tetragonally elongated surroundings with three oxygen atoms from two oxalate ligands, a methylpyrazole-nitrogen defining the equatorial plane, and two other oxalate-oxygen atoms occupying the axial positions. The monodentate 4-Hmpz ligands alternatively extrude above and below each oxalate-bridged copper(II) layer, and the water molecules of crystallization are located between the layers. Compound 1 exhibits a fast and selective adsorption of methylamine vapors to afford the adsorbate of formula {Cu(ox)(4-Hmpz)·3MeNH2·1/3H2O}n (2), which is accompanied by a concomitant color change from cyan to deep blue. Compound 2 transforms into {Cu(ox)(4-Hmpz)·MeNH2·1/3H2O}n (3) under vacuum for three hours. The cryomagnetic study of 1–3 revealed a unique switching from strong (1) to weak (2 and 3) antiferromagnetic interactions. The external control of the optical and magnetic properties along this series of compounds might make them suitable candidates for switching optical and magnetic devices for chemical sensing.

As an emerging class of nitrogenous disinfection by-products, halonitromethanes have caused public health concerns owing to their high toxicity. More and more attention has been paid to the new materials and technologies for the removal of halonitromethanes. In this study, a novel material, nanoscale zero-valent iron (nZVI) supported on MIL-96 (nZVI@MIL-96) with favorable stability and reusability, was synthesized and applied to the adsorption-degradation of trichloronitromethane (TCNM) in the water. The results revealed that almost all the TCNM could be removed under 20 mg/L nZVI@MIL-96 dosage with a wide temperature range. The optimum mass ratio of nZVI to MIL-96 was 1:2, and the TCNM adsorption-degradation followed a pseudo-first-order model. The coexisting ions, such as SO42–, PO43–, and NO3–, with high concentration brought adverse effects on the removal of TCNM; however, the effects of Cl– and CO32– were insignificant. The concentrations of aluminum and iron ions in water were all within the standard value after adsorption with the nZVI@MIL-96. The degradation mechanism of TCNM by nZVI@MIL-96 included two steps, namely, adsorption and degradation, and methylamine was the terminal dechlorination and denitration products. In a word, the as-prepared nZVI@MIL-96 nanoparticles demonstrated the capabilities as a material of adsorption-degradation of TCNM in the water.

Hexamethylentetramine has drawn a lot of attention due to its potential to produce prebiotic species. This work aims to gain a better understanding in the chemical processes concerning methylamine under astrophysically relevant conditions. In particular, this work deeps into the formation of N-heterocycles in interstellar ice analogues exposed to UV radiation, which may lead to the formation of prebiotic species. Experimental simulations of interstellar ice analogues were carried out in ISAC. ISAC is an ultrahigh vacuum chamber equipped with a cryostat, where gas and vapour species are frozen forming ice samples. Infrared and ultraviolet spectroscopy were used to monitor the solid phase, and quadrupole mass spectrometry served to measure the composition of the gas phase. The variety of species detected after UV irradiation of ices containing methylamine revealed the presence of 12 species which have been already detected in the ISM, being 4 of them typically classified as complex organic molecules: formamide (HCONH 2 ), methyl cyanide (CH3 CN), CH3 NH and CH3 CHNH. Warming up of the irradiated CH3 NH2 -bearing ice samples lead to the formation of trimethylentriamine (TMT), a N-heterocycle precursor of HMT, and the subsequent synthesis of HMT at temperatures above 230 K., We would like to devote this paper to the memory of our long- term colleague and dearest friend professor Rafael Escribano from Spanish CSIC, whose advise and stimulating discussions we en- joyed so much. The Spanish Ministry of Science, Innovation and Universities supported this research under grant number AYA2017- 85322-R and MDM-2017-0737 Unidad de Excelencia ‘Mar ́ıa de Maeztu’– Centro de Astrobiología (CSIC-INTA). (AEI/FEDER, UE). PCG acknowledges support from PGC2018-096444-B-I00. HC was supported by PhD fellowship FPU-17/03172. MLS ac- knowledges Ministerio de Economía y Competitividad of Spain for the project AGL2016-80475-R and Comunidad Autónoma of Madrid (Spain) and European funding from FEDER program (project S2018/BAA-4393, AVANSECAL-II-CM).

The development and optimization of an analytical method for the detection and identification of reactive metabolite of organochlorine chemical warfare agent nitrogen mustards (NMs), 2-[(2-chloroethyl)(alkyl)amino]ethanol (CEAAE), known as half nitrogen mustard, in blood samples is presented, herein. In this study, half nitrogen mustards in plasma are presented as a new and unambiguous biomarker of NM exposure since the fully hydrolyzed product, i.e., amino alcohols, are common industrial chemicals that can be present as such without getting exposed to NMs. Thus, the detection of half nitrogen mustard as a biomarker holds great significance for verification by the Chemical Weapon Convention (CWC) and will also be helpful in understanding the pharmacokinetics of NM-based chemotherapeutic pro-drugs. To the best of our knowledge, this is the first report on the detection of half nitrogen mustards in any matrice, including plasma. A very simple sample preparation protocol was developed for its extraction from plasma samples. Heptafluorobutyrylation and gas chromatography-tandem mass spectrometry in the positive chemical ionization mode were developed for the detection and identification of halfNMs. The developed method has shown excellent analytical figures of merits such as a wide range of linearity (1.0–50 ng mL−1), low limit of detection (0.3–0.5 ng mL−1), and low limit of quantification (1.0 ng mL−1). The interday and intraday reproducibilities were also less than 15%. The developed method was successfully applied to real-world samples; in vitro human plasma was spiked with ∼1 ng mL−1 of all the NMs and in vivo studies were done with rats intravenously exposed to 1 × LD50 of bis(2-chloroethyl)methylamine (HN2).

Investigations were conducted to examine the effects of amine type and initial concentration, free chlorine concentration, UV light intensity, pH and tert-butyl alcohol (TBA) on the formation of dichloronitromethane (DCNM) under UV/chlorine. Methylamine (MA), dimethylamine (DMA) and poly-dimethyl diallyl ammonium chloride (PolyDADMAC) were selected as the amine precursors of DCNM. And the reaction products of amines were explored through observing the contents of various nitrogen under UV/chlorine. Experimental results indicated that the higher of the intensity of UV light, the concentration of amines and free chlorine, the greater of the amount of DCNM formation; the amine substance with simple structure is more likely oxidized to form DCNM, so the potential of MA to form DCNM is the largest among three amines; the formation of DCNM decreased with increasing pH from 6.0 to 8.0; due to adding TBA into the reaction solution, halogen and hydroxyl radicals were restrained which resulted the DCNM formation decreased. In the reaction process, the formation of DCNM from amines increased at the beginning, then decreased and almost disappeared due to photodegradation. During the formation and photodegradation of DCNM, the dissolved organic nitrogen could be transformed into the ammonia-nitrogen (NH3-N) and nitrate-nitrogen (NO3−-N).

The chance to have persistent organic radicals in combination with metals has attracted much interest since it offers the possibility of having new functional molecules with multiple open-shell elements. In this study, we report the synthesis of two tripodal tris(2-pyridyl)methylamine ligands (TPMA) functionalized with nitronyl nitroxide persistent radicals. The newly formed ligands have been used to coordinate zinc(II), copper(II), iron(II) and cobalt(II). The resulting complexes have been investigated by means of electron paramagnetic resonance (EPR), ESI-MS, FT-IR spectroscopy and X-ray diffraction. An electron reduction of the N–O radical moiety has been observed, depending on the metal used for the formation of the complex and the reaction conditions. We have observed small differences in the EPR spectra depending on the meta or para position of the radical moiety in the complex structure and some antiferromagnetic interactions between the paramagnetic M(II) ions and the radical species., This work was supported by DGICT-MINECO (MAT2016-80826-R) and AGAUR (2017 SGR 918). ICMAB acknowledges Spanish MINECO for the Severo Ochoa Centres of Excellence Programme Grant SEV-2015-0496.

The thermal treatment of a monolayer of 1-naphthylmethylamine (NMA) on Ni(1 1 1) surface reveals a complex chemistry promoted by the high surface reactivity. Both the amino-terminated functional group and the naphthalene body of NMA undergo a progressive dehydrogenation, which eventually leads to the coalescence of the molecules. As a result, 2D structures of increasing size are synthesized on the surface, characterized by a graphene-like lattice in which nitrogen atoms are mainly incorporated as pyridinic substitutional defects. In this paper, we show the evidence of the formation of extended nitrogen-doped graphene (N-GR) domains at temperatures as low as 300 °C, with band dispersion measurements that reveal p-type doping.

The structure, stability and bonding of beryllium bis(diazaborolyl) derivatives and their Mg and Al-containing analogues have been investigated through the use of G4-high level ab initio methods. This survey allowed us to conclude that not only the Be/B compounds, recently reported in the literature, but also their analogues in which Be is replaced by Mg and B is replaced by Al should exhibit similar bonding characteristics and stability and therefore should be, in principle, also experimentally accessible. In general, in all these derivatives B and Al, in spite of being intrinsically electron-deficient systems, behave as nucleophiles towards Be and Mg. One of the consequences of having two electron-deficient atoms involved in a bond is that the net charge associated to both of them is usually positive, in contrast with typical Be or Mg containing compounds, such as BeF2 or MgF2. However, this apparent dissimilarity is not so, because of the role of the second neighbors. Indeed, in the systems investigated, even though the Be-B, Be-Al, Mg-B or Mg-Al bonds are not too polar as compared with Be-F or Mg-F, the cluster can be viewed as the interaction between a positively charged Be(Mg) atom with two negatively charged ligands. Consistently, the homolytic dissociation enthalpies of the Be-ligand bonds, though smaller than that of the Be-F one, are still significantly large. Also importantly, the Lewis acid character of Be is still preserved, as all the Be compounds investigated lead to rather strong beryllium bonds when interacting with one or two typical Lewis bases, such as methylamine. The same behavior is observed for the corresponding Mg-containing analogues., Financial support from the Ministerio de Ciencia, Innovación y Universidades (projects PGC2018-094644-B-C21, PGC2018-094644-B-C22 and CTQ2016-76061-P) is acknowledged. M. M.Montero-Campillo is grateful to the Ministerio de Ciencia,Innovación y Universidades from Spain for her José Castillejo International Mobility grant (CAS19/00070) at the Laboratoireof Chimie Theòrique (Sorbonne Universitè) in Paris. Thanks are also given to the CTI (CSIC) and the Centro de Computación Científica of the UAM (CCC-UAM) for their continued computa-tional support

Carbon-based perovskite solar cells (PSCs) without hole transport material have attracted much attention due to their high stability. However, their power conversion efficiency (PCE) is still low because of the lack of suitable perovskite deposition methods. In this work, a facile solid-gas reaction method was explored to prepare high quality perovskite and the effects of precursor composition (PbI2, PbI2 + HI, HPbI3 and PbI2 + NH4I) on the CH3NH2 (MA) gas-induced perovskite were systematically investigated. The lack of H+/I− and/or HI suppressed the conversion of PbI2 precursor to MAPbI3, while rapid and complete conversion was achieved for (PbI2 + HI), HPbI3 and (PbI2 + NH4I) precursors. Compared with HPbI3 precursor, the presence of H2O molecules in (PbI2 + HI) precursor lowered the perovskite crystallinity, while the release of NH3 from (PbI2 + NH4I) precursor slower the interaction of MA molecules with MAPbI3 for achieving the highest quality MAPbI3 layer. The application of an anti-solvent treatment during precursor deposition further improved the quality of HPbI3 and (PbI2 + NH4I)-processed perovskite layers, which as a result, significantly promoted the photovoltaic performance of C-PSCs. Both devices exhibited considerably high stability, especially for the (PbI2 + NH4I)-processed C-PSCs, who did not show any PCE degradation after storage in air atmosphere at room temperature for 120 days.

Heterometallic Co/Cd solvatomorphs, which differ by half of the solvent water mol­ecule, show a remarkable variation in the cadmium coordination sphere., 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.

The copper nanoparticles stabilized by nanocrystalline MIL-101 framework (Cu/nano-MIL-101) was reproducibly prepared by following double solvent method combined with liquid phase chemical reduction technique. The characterization of the resulting new material was done by using various analytical techniques including ICP-OES, P-XRD, N2-adsorption-desorption, XPS, FE-SEM, SEM-EDX, BFTEM and HAADF-STEM; the summation of their results reveals that the formation of well-dispersed and very small sized (0.8 nm) copper nanoparticles within nanocrystalline MIL-101 framework. The catalytic performance of Cu/nano-MIL-101 in terms of activity and stability was tested in the hydrolytic dehydrogenation of methylamine borane (CH3NH2BH3), which has been considered as one of the attractive materials for the efficient chemical hydrogen storage. Cu/nano-MIL-101 catalyzes the hydrolytic dehydrogenation of methylamine borane with high activity (turnover frequency; TOF = 257 mol H2/mol Cu × h) and conversion (>99%) under air at room temperature. Moreover, these nano-MIL-101 framework stabilized copper nanoparticles show great durability against to sintering and leaching, which make Cu/nano-MIL-101 reusable nanocatalyst in the hydrolytic dehydrogenation of methylamine-borane. Cu/nano-MIL-101 nanocatalyst retains 83% of its inherent activity at complete conversion even at 10th recycle in the hydrolytic dehydrogenation of methylamine borane.

The mechanisms of noncatalytic and autocatalytic addition–elimination reactions of dimethyl carbonate with methylamine have been studied in terms of wB97XD/6-311++G(df,p), M06/6-311++G(df,p), and PBE0/6-311++G(df,p) quantum chemical methods, and thermodynamic and activation parameters of these reactions have been calculated. The rate-determining stage is the formation of tetrahedral carbon intermediate. The addition–elimination mechanism is preferred over the autocatalytic SN2 mechanism determined by enhanced donor–acceptor and acid–base properties of amine complexes with alcohol associates in comparison to amines.

Polyborosilazane synthesized from trichlorosilane (SiHCl3), boron trichloride (BCl3) and methylamine (MeNH2) is highly sensitive to moisture for hydrolysis of -NHMe unites and is easy to cross-link for dehydrogenation of Si-H, N-H, which affected the industrial scale production of SiBNC ceramic fibers. In this paper,a new nitrogen source(n-propylamine, C3H7NH2) was used instead of MeNH2 to synthesis polyborosilazane precursor. The influences of nitrogen sources on the structures and properties of SiBNC ceramic fiber precursors were investigated. As compared to SiHCl3/BCl3/CH3NH2 system, polyborosilazane precursor synthesized from the SiHCl3/BCl3/C3H7NH2 system exhibited lower crosslink density, lower sensitivity to moisture and good melt spinnability, and the obtained ceramic fibers showed higher tensile strength (1.03 GPa, an increase of about 37.3%). This synthesis route (SiHCl3/BCl3/C3H7NH2) may serve as a suitable synthetic route for a large-scale production of SiBNC ceramic fibers.

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.

Metal coordination complexes can display interesting biological activity, as illustrated by the bleomycins (BLMs), a family of natural antibiotics that when coordinated to a redox-active metal ion, show antitumor activity. Yet, which metal ion is required for the activity in cells is still subject to debate. In this study, we described how different metal ions affect the intracellular behavior and activity of the synthetic BLM-mimic N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine (N4Py). Our study shows that a mixture of iron(II), copper(II), and zinc(II) complexes can be generated when N4Py is added to cell cultures but that the metal ion can also be exchanged by other metal ions present in cells. Moreover, the combination of chemical data, together with the performed biological experiments, shows that the active complex causing oxidative damage to cells is the FeII-N4Py complex and not per se the metal complex that was initially added to the cell culture medium. Finally, it is proposed that the high activity observed upon the addition of the free N4Py ligand is the result of a combination of scavenging of biologically relevant metals and oxidative damage caused by the iron(II) complex., N4Py and its metal coordination complexes show activity against cancer cells. It is shown that in vivo metal-ion exchange is very important and that the iron(II) complex, which is demonstrated to be responsible for the observed biological activity, is formed predominantly. Hence, it should be realized that the intracellularly active complex of a metal-coordinating compound does not necessarily correspond to the initially added metal complex but that metal exchange can occur.

The mono- and binuclear Schiff base complexes [CoL3]·DMF (1) and [CoCdL3Cl2]·0.5H2O (2) were facilely synthesized using zerovalent cobalt and cadmium chloride (for 2) as starting materials and the pre-formed pro-ligand HL (2-methoxy-6-[(methylimino)methyl]phenol, the product of condensation of o-vanillin and methylamine) in air. The compounds were characterized by single crystal X-ray diffraction analysis and spectroscopic methods in solution and in the solid state. Both complexes demonstrate a profound catalytic activity in the stereoselective oxidation of cis-1,2-dimethylcyclohexane (model substrate) with m-CPBA (m-chloroperbenzoic acid) under mild conditions in the presence of promoters of various acidity (HNO3, TFA and HOAc). The heterometallic binuclear CoIIICdII pre-catalyst (2) was more active than the mononuclear CoIII one (1), exhibiting higher products yields up to 51% and excellent stereospecificity (up to 99.2% retention of stereoconfiguration). This result could be associated with a synergistic effect of two different metals in 2. Based on the large obtained kinetic isotope effect and H218O labeling studies, the overall reaction mechanism was proposed to proceed without the participation of free alkyl radicals. The acidity of the promoter was shown to influence catalytic parameters for both 1 and 2 so that the better parameters are achieved with the acid possessing lower pKa values (a stronger acid). The comparison of the catalytic behaviours of 1 and 2 is discussed in detail considering relevant examples from the literature.