Search

The problem of sodium and potassium in the attosecond pulse train (APT) as a kicking field is considered. The goal is to investigate the possibility of the kicking field to generate, in general, any secondary radiation. The modifications of the energy bands and the kick-induced currents are examined. Simple local pseudopotentials have been proposed and used. It is demonstrated that the APT generates secondary radiation in a wider spectral range similar to high-order harmonic generation (HHG). This radiation has been found to have a form of periodic complex peak compositions decreasing in intensity with the period approximately equal to the doubled angular frequency of the driving field. This is a new effect. A physical explanation of this effect is given.

Lithium is an economically important element that is increasingly extracted from brines accumulated in continental basins. While a number of studies have identified silicic magmatic rocks as the ultimate source of dissolved brine lithium, the processes by which Li is mobilized remain poorly constrained. Here we focus on the potential of low-temperature, post-eruptive processes to remove Li from volcanic glass and generate Li-rich fluids. The rhyolitic glasses in this study (from the Yellowstone-Snake River Plain volcanic province in western North America) have interacted with meteoric water emplacement as revealed by textures and a variety of geochemical and isotopic signatures. Indices of glass hydration correlate with Li concentrations, suggesting Li is lost to the water during the water-rock interaction. We estimate the original Li content upon deposition and the magnitude of Li depletion both by direct in situ glass measurements and by applying a partition-coefficient approach to plagioclase Li contents. Across our whole sample set (19 eruptive units spanning ca. 10 m.y.), Li losses average 8.9 ppm, with a maximum loss of 37.5 ppm. This allows estimation of the dense rock equivalent of silicic volcanic lithologies required to potentially source a brine deposit. Our data indicate that surficial processes occurring post-eruption may provide sufficient Li to form economic deposits. We found no relationship between deposit age and Li loss, i.e., hydration does not appear to be an ongoing process. Rather, it occurs primarily while the deposit is cooling shortly after eruption, with δ18O and δD in our case study suggesting a temperature window of 40° to 70°C.

Alkali metals are commonly used to promote heterogeneous catalysts. For instance, K can enhance the MoS2-catalyzed synthesis of methanethiol, an important industrial chemical, from CO/H2/H2S. Herein, we not only demonstrate that the synergy increases with alkali cation size (Cs > Rb > K > Na) but also that alkali sulfides themselves are the active sites. The alkali-normalized methanethiol formation rate of Cs sulfide is nearly the same as that of Cs-promoted MoS2 with a much lower yield of unwanted methane. Kinetic measurements show that methanethiol on alkali sulfides is formed via the reaction 3 CO + 2 H2S → COS + CO2 + CH3SH. This represents a first example of H2S as a hydrogen donor for the formation of the thiol counterpart of methanol. The role of MoS2 is that of a promoter that disperses alkali and provides spillover H from H2 dissociation.

Получена тонкая пленка интерметаллида LiAu при комнатной температуре при напылении атомов Li на слой адсорбированного золота на поверхности вольфрама. Исследованы процессы электронно-стимулированной десорбции (ЭСД) атомов Li с поверхности LiAu. Показано, что ЭСД атомов Li может наблюлаться только в том случае, когда напылено не менее одного монослоя атомов Li и с Au . Зависимость выхода ЭСД атомов Li от количества напыленного Li и Au имеет максимум при напылении двух монослоев атомов Li на Au. Полученные результаты свидетельствуют о формировании LiAu различной стехиометрии: от LiAu с дефицитом атомов лития до LiAu при напылении двух монослоев атомов Li. В энергетическом распределении по кинетическим энергиям десорбирующихся атомов Li обнаружено два пика: высокоэнергетический и низкоэнергетический. Первый из них связан с десорбцией атомов Li из LiAu, а второй в десорбцией атомов Li из верхнего монослоя атомов Li. A thin film of the intermetallic compound LiAu was obtained at room temperature by deposition Li atoms onto a layer of adsorbed gold on the tungsten surface. The processes of electron-stimulated desorption of Li atoms from the surface are investigated. It is shown that electron-stimulated desorption of Li atoms can be observed only in the case when at least one monolayer of Li and Au atoms is deposited. The dependence of the electron-stimulated desorption yield of Li atoms on the amount of deposited has a maximum when two monolayers of atoms Li are deposited on Au . The results obtained indicate the LiAu formation of various stoichiometry: from with a deficit of lithium atoms to the deposition of two monolayers of atoms. In the kinetic energy distribution of desorbed Li atoms, two peaks were found: high-energy and low-energy. The first of them is associated with the desorption of Li atoms from LiAu, and the second with the desorption of Li atoms from the upper monolayer of Li atoms.

The electronic and magnetic properties of armchair-hexagonal (AHEX) and zigzag-triangular (ZTRI) graphene quantum dots doped with alkali metals are investigated using density functional theory. The binding energy confirms the stability of the undoped systems. Although doping decreases stability of single layer structures, in bilayer ones the binding energy between the layers increases. The former is due to the broken bonds and the deformation at the surface, while the later is due to the chemical bonds formation between the layers. We found that the lowest ground state energy for AHEX/AHEX-doped is the singlet/quadruplet spin state. Therefore, AHEX dots experience transformation from diamagnetic to ferromagnetic state after doping. In addition, the optimized spin state for ZTRI/ZTRI-doped is the quintet/sextet spin-polarized state. In few cases, the doped AHEX/ZTRI dots have doublet/quadruplet spin state due to the strong interaction between the flake atoms that passivates some unpaired electrons. Magnetic properties depend also on stacking, for instance pristine bilayer triangular flakes become antiferromagnetic due to pairing between edge states. The energy gap significantly affected by doping, for instance the gap decreases from ~3.7 eV in hexagonal flakes to 1.5 eV when it is doped with Na in the upper position. Electrons from the broken bonds around the doped metal form orbitals loosely bound to the flake consequently decreasing the energy gap. On the other hand, stacking increases the energy gap in bilayer triangular flakes due to the mutual passivation of the reactive edge states from both the layers. The calculated spin up/down density ratio is high in hexagonal flakes leading to high spin polarization (P), for instance P = 0.64 in hexagonal flakes doped with K atom. The found enhanced spin polarization, in addition to the tunable magnetic properties, makes doped graphene flakes promising candidates for spintronic devices.

Unprecedented metalated phosphonite boranes were prepared from PH‐substituted precursors and silyl amides. Although potassium derivatives were thermally stable and could even be isolated and structurally characterised, lithiated analogues proved to be unstable towards self‐condensation under cleavage of LiOR at ambient temperature. Reaction studies revealed that the metalated phosphonite boranes exhibit ambiphilic character. Their synthetic potential as nucleophilic building blocks was demonstrated in the synthesis of the first stannylated phosphonite representing a new structural motif in phosphine chemistry., Metalation of diorganophosphonite boranes gave unprecedented O‐substituted phosphide reagents as spectroscopically detectable and even isolable species. The target compounds are ambiphiles that undergo P−O bond functionalisation upon treatment with nucleophiles and act as nucleophilic building blocks towards electrophiles. The latter reactions allow accessing phosphines with unmatched substituent patterns.

MXenes’ tunable properties make them excellent candidates for many applications in future nanoelectronics. In this work, we explore the suitability of Sc[Formula: see text]CX (X=N[Formula: see text], ON, O[Formula: see text]) MXenes to act as the active anode materials in Na-ion based batteries (NIBs) by means of ab initio simulations. After analyzing the structural and elastic properties of all the possible models to evaluate the energetically favorable N and O functionalization sites, our calculations show that both Sc[Formula: see text]CON and Sc[Formula: see text]CN[Formula: see text] present a clear metallic character, making them potential candidates as anode materials. The investigation of the most relevant features for anode performance, such as the adsorption and diffusion of Na atoms, the intrinsic capacity, the open circuit voltage, and the storage capacity, shows that both systems are serious alternatives to the most common 2D materials currently employed in alkali metal batteries. In particular, Sc[Formula: see text]CN[Formula: see text] presents better diffusion behavior thanks to the absence of Na clustering on its surface, with optimal diffusion barriers comparable to other 2D materials, such as MoN[Formula: see text], while the values of diffusion barriers for Sc[Formula: see text]CON are at least three times smaller than those found for other anode candidates. Similarly, while the capacity of Sc[Formula: see text]CON is close to the one reported for 2D Sc[Formula: see text]C, Sc[Formula: see text]CN[Formula: see text] possesses a power density more than twice higher than the ones of 2D materials, such as Sc[Formula: see text]C, graphite, and MoS[Formula: see text]. Our results, thus, confirm the urge for further experimental exploration of the MXene Sc[Formula: see text]CX (X=N[Formula: see text], ON, O[Formula: see text]) family as anode material in NIBs.

K and Na have been widely used in photocatalytic H2O2 production. However, Rb and Cs have rarely been studied for their photocatalytic potentials. In addition, the mechanism regulating H2O2 production from different alkali metal (M)-modified polymeric carbon nitride (PCN) is still unknown. Therefore, M-doped PCN was fabricated using thermal copolymerization in the presence of Li, Na, K, Rb, or Cs. The activity of CN-M was enhanced by the increase in the metallic character of alkali metals. However, CN-Cs’s photocatalytic H2O2 activity is not optimal even though it has the strongest metallic character. A stronger metallic character is anticipated to yield stronger Lewis acidic sites. Although ethanol can be adsorbed and activated at strong Lewis acidic sites, H2O2 can also be activated at these sites, which speeds up H2O2 degradation. CN-Rb—with its acceptable metallic character, excellent oxygen adsorption capacity, and reduced H2O2 degradation—has the best photocatalytic H2O2 yield.

Создан ультратонкий слой интерметаллида KAu при комнатной температуре при напылении атомов калия на слой адсорбированного золота на поверхности вольфрама. Исследованы процессы электронно-стимулированной десорбции атомов K с поверхности KAu. Найдены квазирезонансные пики в зависимости выхода ЭСД от энергии возбуждения при 64 и 82 эВ, которые соответствуют возбуждению остовных уровней Au 5р и Au 5р. Полученные результаты свидетельствуют о формировании KAu различной стехиометрии: от KAu до KAu. Показано, что интерметаллид KAu, полученный при комнатной температуре, как полученный ранее KAu при 1000K, является полупроводником. Предложена модель электронно-стимулированной десорбции атомов K в системе K/KAu/Au/W. An ultrathin intermetallic layer KAuwas created at room temperature by depositing potassium atoms on adsorbed gold layer on the tungsten surface. The processes of electron-stimulated desorption of K atoms from the KAu surface are investigated. Quasi-resonance peaks are found in the dependence of the ESD yield on the excitation energy at 64 and 82 eV, which correspond to the excitation of the core levels Au 5p and Au 5p. The obtained results indicate the formation KAu of different stoichiometry: from KAu to KAu . It is shown that the intermetallic compound KAu created at room temperature is a semiconductor, as it was previously obtained at 1000 K. A model of electron-stimulated desorption of K atoms in the K / KAu / Au / W system is proposed.

На базе электронно-статистического метода получены выражения и рассчитаны дисперсионная и поляризационная поправки к поверхностной энергии граней кристаллов IA металлов на границе с вакуумом. Обе поправки сильно анизотропны. Дисперсионная поправка увеличивает величину поверхностной энергии граней (от 3 до 23 %), поляризационная - снижает менее, чем на 1%. Учет данных взаимодействий улучшает согласие результатов расчета поверхностной энергии с экспериментальными данными расплавов. On the basis of the electronic statistical method, expressions for the dispersion and polarization corrections to the surface energy of the crystal faces 1A of metals at the boundary with vacuum are obtained and their value are calculated. Both corrections are highly anisotropic. The dispersion correction increases the surface energies of the faces (from 3 to 23 %), the polarization correction reduces them by less than 1%. Taking into account these interactions improves the agreement between the calculated surface energy and the experimental data of the melts.

Organolithium compounds have been at the forefront of synthetic chemistry for over a century, as they mediate the synthesis of myriads of compounds that are utilised worldwide in academic and industrial settings. For that reason, lithium has always been the most important alkali metal in organometallic chemistry. Today, that importance is being seriously challenged by sodium and potassium, as the alkali‐metal mediation of organic reactions in general has started branching off in several new directions. Recent examples covering main‐group homogeneous catalysis, stoichiometric organic synthesis, low‐valent main‐group metal chemistry, polymerization, and green chemistry are showcased in this Review. Since alkali‐metal compounds are often not the end products of these applications, their roles are rarely given top billing. Thus, this Review has been written to alert the community to this rising unifying phenomenon of “alkali‐metal mediation”., Alkali metals top the league when it comes to mediating reactions. Organolithium compounds have long been their captain, but now organosodium and organopotassium compounds are finding their form too. This Review highlights their victories in homogeneous catalysis, organic synthesis, low‐valent aluminium chemistry, polymerization, and green chemistry.

Lochmann–Schlosser superbases (LSB) are a standard reagent in synthetic chemistry to achieve an exchange of a proton on an organic framework with an alkali metal cation, which in turn can be replaced by a wide range of electrophilic groups. In standard examples, the deprotonating reagent consists of an equimolar mixture of n‐butyllithium and potassium t‐butoxide. However, the nature of the reactive species could not be pinned down either for this composition or for similar mixtures with comparable high reactivity. Despite the poor solubility and the fierce reactivity, some insights into this mixture were achieved by some indirect results, comparison with chemically related systems, or skillful deductions. Recent results, mainly based on new soluble compounds, delivered structural evidence. These new insights lead to advanced and more detailed conclusions about the interplay of the involved components., Navigating in treacherous but treasure‐laden seas where alkyllithium and potassium alkoxides were discovered by Lochmann and Schlosser mix. Little is known about the uncharted areas away from the well‐known coastal regions of the starting materials. Many molecular vessels were precipitated and lost here. Progress was finally made by careful hopping from molecular island to island.

Metalation of secondary diaminophosphine boranes by alkali metal amides provides a robust and selective access route to a range of metal diaminophosphide boranes M[(R2N)2P(BH3)] (M=Li, Na, K; R=alkyl, aryl) with acyclic or heterocyclic molecular backbones, whereas reduction of a chlorodiaminophosphine borane gave less satisfactory results. The metalated species were characterized in situ by NMR spectroscopy and in two cases isolated as crystalline solids. Single‐crystal XRD studies revealed the presence of salt‐like structures with strongly interacting ions. Synthetic applications of K[(R2N)2P(BH3)] were studied in reactions with a 1,2‐dichlorodisilane and CS2, which afforded either mono‐ or difunctional phosphine boranes with a rare combination of electronegative amino and electropositive functional disilanyl groups on phosphorus, or a phosphinodithioformate. Spectroscopic studies gave a first hint that removal of the borane fragment may be feasible., It′s just so plain borane: Alkali metal diaminophosphide boranes, which can be selectively prepared by metalation of PH‐substituted precursors with non‐nucleophilic amides, were for the first time isolated and characterized crystallographically. Their synthetic application as highly functional nucleophilic building blocks is illustrated in metatheses with a dichlorodisilane and the formation of a stable carbon disulfide adduct.

Insights gained from a comparison of aminometalation reactions with lithium amides, potassium amides and mixed lithium/potassium amides are presented. A combination of structural characterization, DFT calculations and electrophile reactions of aminometalated intermediates has shown the advantages of using a mixed metal strategy. While potassium amides fail to add, the lithium amides are uncontrollable and eliminated, yet the mixed K/Li amides deliver the best of both systems. Aminopotassiation proceeds to form the alkylpotassium species which has enhanced stability over its lithium counterpart allowing for its isolation and thereby its further characterization., The use of a mixed‐metal system consisting of LiNR2/KOR increases the selectivity of the aminometalation of styrene derivatives in favour of a potassiated intermediate over a polymerization product. Crystal structures along with quantum chemical calculations and experimental investigations demonstrate the additional advantages of potassium over lithium or sodium for the stability of metalated phenylethylamines.

This dissertation summarizes my research in the Nuckolls group on two projects, with a central theme of achieving control of electronic coupling in various nanoscale systems. The two studies of interest aim at the study of emerging properties from alkali-doping of polyaromatic hydrocarbons (PAH), and the synthesis of novel metal chalcogen molecular clusters. Chapter 1 is divided into two parts. Part one provides a brief history of the forces we associate with bond formation. We will learn that although defining a ���chemical bond��� is helpful, it is limited to our incomplete understanding of what forces contribute to its existence. The behavior of an electron in externally applied magnetic fields will be discussed, where the collective behavior of electrons in a material can be measured, showing a myriad of emerging properties. The known superconducting alkali-doped PAHs are introduced, followed by the unresolved problems of reproducibility and lack of structural data to accompany superconducting samples. Finally, the proximity of AFM to superconductivity is discussed, which could give us insights on further exploration of hight temperature organic superconductors. Part two introduces atomically precise clusters of atoms, also knows as superatoms. Various synthetic approaches to create metal chalcogenide superatoms are introduced. Next, a closer look into the cobalt selenide core, [Co6Se8], is presented. The ability to selectively substitute the ligands on this superatom, achieves dimensional control. The subunit can be seen as a 0-dimensional subunit, where it readily gives away its electrons. Furthermore, assembly of the clusters into 1-, 2-, and 3-dimensional structures is described. Chapter 2 introduces a novel approach to acquire phase pure alkali-doped PAHs, p-terphenyl specifically. Previous reports of solution-processed doping of PAH have inspired highly reliable synthesis of these salts, by employing a chelating agent to stabilize the alkali metal. The first half of chapter 2 analyzes one such crystal in detail, describing emerging AFM fluctuations. The AFM coupling between nearest neighboring p-terphenyls occurs in all three crystallographic directions. Interestingly, this coupling can be seen as an unconventional bond between two terphenyl units along the hard axis, and resembles resonance structures seen in polyacetylene. The second half of the chapter further investigates the novel method, obtaining a library of alkali-doped p-terphenyls. This approach allows for selective variation of either the alkali-metal, the chelating agent, or the electronic structure of p-terphenyl. Obtaining nearly a dozen structures allows for a study of trends of doping level and accompanied magnetic properties. Lastly, Chapter 3 proves a new mechanism for ligand substitution of cobalt selenide superatomic clusters, using an easily removable carbene as the ligand. This approach grants access to new surface ligands and core shapes to expand the properties of these superatoms. Through this approach, larger atomically precise materials can be targeted, giving rise to new types of electronic properties.

International audience; In view of a sustainable recycling process, the leaching mechanisms of nickel and rare‐earth elements (REEs) contained within industrial samples of spent nickel metal hydride battery powders were investigated in HCl and H2SO4, under mild temperature (25–60 °C) and pH (3–5.5). First, in‐depth characterization of the heterogeneous battery powder was carried out with powder XRD, SEM, electron probe microanalyzer wavelength‐dispersive spectroscopy (EPMA‐WDS) quantitative analyses of individual particles, and inductively coupled plasma optical emission spectrometry (ICP‐OES) elemental analysis. An unusual result is the identification of particles that exhibit a core–shell structure, which is related to anode active mass aging mechanisms. Then, a leaching study in a 10 L pilot‐scale reactor demonstrated the selective dissolution of REEs, with respect to nickel, at pH 3, which is attributed to 1) the kinetic inhibition of nickel metal dissolution, and 2) the specific core–shell structure of aged mischmetal particles. Furthermore, the use of H2SO4 led to coprecipitation of lanthanide–alkali double sulfates and nickel salts.

The electron-stimulated desorption of neutral lithium atoms from the oxygen monolayer covered the tungsten surface have been studied. The model of the atom electron-stimulated desorption processes on the tungsten surface with the adsorbed oxygen monolayer have been suggested. Both common and different features of the electron-stimulated desorption processes have been foundfor high-energy and low-energy peaks in the kinetic energy distributions of the desorbed atoms.

Recent progress in doping of halide perovskite materials (HPM) by using targeted elements has provided a dimension beyond structural and compositional modification, for achieving desired properties and resulting device performance. Herein doping of alkali metal ions (Li+, Na+, K+, Rb+, and Cs+) in three-dimensional HPM is reviewed to lay a particular focus on advances in synthesis, doping-induced changes in optical and electrical properties, and their optoelectronic applications. The introduction of alkali metals in HPM shows an effective route for improved morphology, suppressed ion migration, reduction in non-radiative recombination, passivation of bulk and interface defects, and increased thermal stability. In the end, we provide our perspective that the effect of alkali metal incorporation on the efficiency and stability of HPM should be further investigated via in-situ characterization methods and doped HPM should be considered for more functional applications. Graphical abstract

The incorporation of heavy alkali metals into substrates is both challenging and essential for many reactions. Here, we report the formation of THF-solvated alkali metal benzyl compounds [PhCH2M ��� (thf)n] (M=Na, Rb, Cs). The synthesis was carried out by deprotonation of toluene with the bimetallic mixture n-butyllithium/alkali metal tert-butoxide and selective crystallization from THF of the defined benzyl compounds. Insights into the molecular structure in the solid as well as in solution state are gained by single crystal X-ray experiments and NMR spectroscopic studies. The compounds could be successfully used as alkali metal mediating reagents. The example of caesium showed the convenient use by deprotonating acidic C���H as well as N���H compounds to gain insight into the aminometalation using these reagents., Chemistry - a European journal;27(71)

The adeninate anion (Ade−) is a useful nucleophile used in the synthesis of many prodrugs (including those for HIV AIDS treatment). It exists as a contact ion-pair (CIP) with Na+ and K+ (M+) but the site of coordination is not obvious from spectroscopic data. Herein, a molecular-wide and electron density-based (MOWED) computational approach implemented in the implicit solvation model showed a strong preference for bidentate ion coordination at the N3 and N9 atoms. The N3N9-CIP has (i) the strongest inter-ionic interaction, by −30 kcal mol−1, with a significant (10–15%) covalent contribution, (ii) the most stabilized bonding framework for Ade−, and (iii) displays the largest ion-induced polarization of Ade−, rendering the N3 and N9 the most negative and, hence, most nucleophilic atoms. Alkylation of the adeninate anion at these two positions can therefore be readily explained when the metal coordinated complex is considered as the nucleophile. The addition of explicit DMSO solvent molecules did not change the trend in most nucleophilic N-atoms of Ade− for the in-plane M-Ade complexes in M-Ade-(DMSO)4 molecular systems. MOWED-based studies of the strength and nature of interactions between DMSO solvent molecules and counter ions and Ade− revealed an interesting and unexpected chemistry of intermolecular chemical bonding.

This paper presents an analysis of data on the cross sections of elastic and inelastic collisions of electrons with noble gases, alkali and other atoms. For the selected sets of experimental and theoretical data, optimal analytical formulas are found, and approximation coefficients are calculated. The obtained semi-empirical formulas reproduce the values of the transport (diffusion), excitation and ionization cross sections for noble gases. Much attention is paid to the ionization cross sections of metal atoms, which are often present as an impurity in gas-discharge plasma. The approximation formulas reproduce the values of the ionization cross sections for hydrogen, metal and other elements in a wide range of energies with accurate orders of errors of the available theoretical and experimental data. For some elements with a two-hump plot of the dependence of the ionization cross section on the collision energy, it is proposed to use a two-term formula that takes into account ionization from both external and internal shells.

The processes of electron-stimulated desorption of Cs atoms from the graphene film on the iridium ribbon have been studied. The model of the Cs atom electron-stimulated desorption processes from the graphene film have been suggested. It has been shown the community and the difference of the electron-stimulated desorption processes for high-energy and low-energy peaks in the kinetic energy distributions of the desorbed atoms.

The preparation of a series of alkali-metal inclusion complexes of the molecular cube [{CoIII(Me3-tacn)}4{FeII(CN)6}4]4- (Me3-tacn = 1,4,7-trimethyl-1,4,7-triazacyclononane), a mixed-valent Prussian Blue analogue bearing bridging cyanido ligands, has been achieved by following a redox-triggered self-assembly process. The molecular cubes are extremely robust and soluble in aqueous media ranging from 5 M [H+] to 2 M [OH-]. All the complexes have been characterized by the standard mass spectometry, UV-vis, inductively coupled plasma, multinuclear NMR spectroscopy, and electrochemistry. Furthermore, X-ray diffraction analysis of the sodium and lithium salts has also been achieved, and the inclusion of moieties of the form {M-OH2}+ (M = Li, Na) is confirmed. These inclusion complexes in aqueous solution are rather inert to cation exchange and are characterized by a significant decrease in acidity of the confined water molecule due to hydrogen bonding inside the cubic cage. Exchange of the encapsulated cationic {M-OH2}+ or M+ units by other alkali metals has also been studied from a kineticomechanistic perspective at different concentrations, temperatures, ionic strengths, and pressures. In all cases, the thermal and pressure activation parameters obtained agree with a process that is dominated by differences in hydration of the cations entering and exiting the cage, although the size of the portal enabling the exchange also plays a determinant role, thus not allowing the large Cs+ cation to enter. All the exchange substitutions studied follow a thermodynamic sequence that relates with the size and polarizing capability of the different alkali cations; even so, the process can be reversed, allowing the entry of {Li-OH2}+ units upon adsorption of the cube on an anion exchange resin and subsequent washing with a Li+ solution., Financial support by Grant PID2019-107006GB-C21 funded by MCIN/AEI/10.13039/501100011033 is acknowledged.

s‐Block metal carbenoids are carbene synthons and applied in a myriad of organic transformations. They exhibit a strong structure–activity relationship, but this is only poorly understood due to the challenging high reactivity and sensitivity of these reagents. Here, we report on systematic VT and DOSY NMR studies, XRD analyses as well as DFT calculations on a sulfoximinoyl‐substituted model system to explain the pronounced solvent dependency of the carbenoid stability. While the sodium and potassium chloride carbenoids showed high stabilities independent of the solvent, the lithium carbenoid was stable at room temperature in THF but decomposed at −10 °C in toluene. These divergent stabilities could be explained by the different structures formed in solution. In contrast to simple organolithium reagents, the monomeric THF‐solvate was found to be more stable than the dimer in toluene, since the latter more readily forms direct Li/Cl interactions which facilitate decomposition via α‐elimination., Whereas in conventional organolithium chemistry unsolvated dimers are generally more stable than solvated monomers and their sodium and potassium analogues are less stable still, curiously this trend seems to be reversed in carbenoid systems. DOSY‐NMR, SC‐XRD analyses and computational studies on a chiral test system show dramatic changes in the stability depending on the solvent and the formed structures.

To understand the dynamics of accident-derived radioactive cesium (137Cs) in stem wood that had a substantial amount of heartwood at the time of the Fukushima Dai-ichi Nuclear Power Plant accident, the radial and vertical distributions of 137Cs activity concentration in stem wood of Japanese cedar (Cryptomeria japonica), cypress (Chamaecyparis obtusa), and larch (Larix kaempferi) were investigated. In addition, the natural distribution of stable cesium (133Cs), rubidium (85Rb), and potassium (39K) concentrations was analyzed to determine the characteristics of 137Cs distribution. Wood disks were collected from the tree stems of six cedars, three cypresses, and two larches at multiple heights in 2014, and the concentrations were measured every 2 cm in the radial direction. 137Cs distribution in stem wood differed among tree species, sampling site, and vertical position of the stem within a tree. Statistical analyses suggested that the radial distribution of 137Cs within the heartwood can be explained by the heartwood moisture content and the distance from the treetop, regardless of species, while the distribution between sapwood and heartwood was dependent on the heartwood cross-sectional area and was additionally different between larch and other species. Similarly, the heartwood/sapwood concentration ratios of stable alkali metals differed between larch and the other species. In the larch, the ratio was ca. 0.5 for all elements, but the ratio was over 1.0 and differed among elements in the other species. Consequently, the species-specific difference in the distribution of 137Cs between sapwood and heartwood was considered to be due to different activity levels of radial transport toward the heartwood. The radial variation pattern of the 137Cs/133Cs concentration ratio showed that less 137Cs was transferred to the inner heartwood compared with the 133Cs distribution pattern in many trees; however, there was also a tree in which 137Cs was excessively transferred to the inner heartwood compared with the 133Cs distribution pattern. Such patterns may result from a combination of significant foliar uptake of 137Cs and poor root uptake after the accident, in addition to the high moisture content of the heartwood.

The depletion of fossil fuels, the rapid evolution of the global economy, and high living standards require the development of new energy‐storage systems that can meet the needs of the world's population. Metal–oxygen batteries (M=Li, Na) arise, therefore, as promising alternatives to widely used lithium‐ion batteries, due to their high theoretical energy density, which approaches that of gasoline. Although significant progress has been made in recent years, there are still several challenges to overcome to reach the final commercialization of this technology. One of the most limiting and challenging factors is the development of bifunctional cathodes towards oxygen reduction and evolution reactions. In this sense, graphene, which is very promising and tunable, has been widely explored by the research community as a key material for this technology. Herein, a wide literature overview is presented and analyzed with the aim of guiding future research in this field., Future is flat: Graphene is a very versatile and promising air cathode in M–O2 (M=Li, Na) batteries due to its high electronic conductivity, large specific surface area, high mechanical strength, low density, and intrinsic catalytic activity towards oxygen reduction and reactions.

The preparation and isolation of the metalated ylides [Cy3PCSO2Tol]M (Cy1‐M) (with M = Li, Na, K) are reported. In contrast to its triphenylphosphonium analogue the synthesis of Cy1‐M revealed to be less straight forward. Synthetic routes to the phosphonium salt precursor Cy1‐H2 via different methods revealed to be unsuccessful or low‐yielding. However, nucleophilic attack of the ylide Cy3P = CH2 at toluenesulfonyl fluoride under basic conditions proved to be a high‐yielding method directly leading to the ylide Cy1‐H. Metalation to the yldiides was finally achieved with strong bases such as nBuLi, NaNH2, or BnK. In the solid state, the lithium compound forms a tetrameric structure consisting of a (C–S–O–Li)4 macrocycle, which incorporates an additional molecule of lithium iodide. The potassium compound forms a C 4‐symmetric structure with a (K4O4)2 octahedral prism as central structural motif. Upon deprotonation the P–C–S linkage undergoes a remarkable contraction typical for metalated ylides., John Wiley & Sons, Ltd.

Understanding the origin and mechanisms of luminescence is a crucial point when it comes to the development of new phosphors with targeted luminescence properties. Herein, a new phosphor belonging to the substance class of alkali metal lithosilicates with the generalized sum formula Cs4−x−y−zRbxNayLiz[Li3SiO4]4:Eu2+ is reported. Single crystals of the cyan‐emitting UCr4C4‐type phosphor show a peculiar double‐band luminescence with one ultranarrow emission band at 473 nm and a narrow emission band at 531 nm under excitation with UV light (λ exc=408 nm). Regarding occupation of the channels by the light metal ions, investigations of single‐crystal XRD data led to the assumption that domain formation with distinct lithium‐ and sodium‐filled channels occurs. Depending on which of these channels hosts the activator ion Eu2+, a green or blue emission results. The herein‐presented results shed new light on the luminescence process in the well‐studied UCr4C4‐type alkali metal lithosilicate phosphors., Double peak: An alkali metal lithosilicate phosphor with generalized sum formula Cs4−x−y−zRbxNayLiz[Li3SiO4]4:Eu2+ was synthesized by a solid‐state reaction. A special property of this UCr4C4‐type compound is the peculiar green and blue double‐band luminescence. This property is apparently related to the filling of the light‐alkali‐metal channels to the extent that lithium and sodium domains are formed, which generate different environments for the activator‐ion site.

CO2 methanation is typically carried out using Ni-supported catalysts containing promoters such as alkali or alkali-earth metals to improve their properties. In this work, bimetallic Ni-based USY zeolite catalysts containing alkali (Li, K and Cs) and alkali-earth (Mg, Ca) metal compounds were prepared using the same conditions (15 wt% of metals, co-impregnation), characterized by N2 sorption, XRD, TGA, CO2 adsorption–desorption, DRS UV-Vis and H2-TPR, and finally applied in CO2 methanation reaction (86,100 mL h−1 g−1, PCO2 = 0.16 bar, H2:CO2 = 4:1). For each group, the effects of the second metal nature on the properties and performances were assessed. Alkali metals incorporation induced considerably low catalytic performances (CH4 yields &lt, 26 %), attributed to their negative impact on zeolite structure preservation. On the contrary, alkali-earth metal-containing catalysts exhibited lower structural damage. However, the formation of Ni-Mg mixed oxides in Ni-Mg/USY catalyst and CaCO3 during the reaction in Ni-Ca/USY sample could explain their performances, similar or lower than those obtained for Ni/USY catalyst. Among the studied metals, calcium was identified as the most interesting (CH4 yield of 65 % at 415 °C), which was ascribed to the slight improvement of the Ni0 dispersion.

Within the frames of a modified version of the electronic statistical theory, an amendment to the interfacial energy at the metal-nonpolar organic liquid interface on the polarization of metal ions of the transition layer in the field of a semi-infinite metal is obtained. An effect of the correction on the macroscopic dielectric permeability of the liquid and orientation of the metallic crystal is established.

We have studied the processes of electron-stimulated desorption (ESD) of neutral lithium atoms from oxidized tungsten. A model has been suggested of the ESD processes from an oxidized tungsten surface. It has been shown the community and the difference of the ESD processes for high-energy and low-energy peaks in the atomic energy distributions.

Biomass gasification is a very efficient process to produce clean energy in the form of a fuel gas (syngas). Hazelnut shells and poplar have good energy production potential and they are abundant in nature. Hazelnut shells have the characteristics of a very good fuel and poplar is among the fastest growing trees; furthermore, poplar demonstrated the capability to absorb organic contaminants (i.e. heavy metals) from the soil in which they are cultivated. However, poplar is not usually used for biomass gasification and its potential is not fully assessed. Here, 3 types of biomass, hazelnut shells (HS), simple poplar (P) and poplar coming from a phytoremediation procedure (PHYP), were chosen as representative samples to be characterized and tested in a steam gasification process carried out on a bench scale fluidized bed gasifier. A comparison is reported on gasification results, such as gas composition, tar production and gas yield for the biomass feedstocks mentioned above. It was concluded that hazelnut shells and poplar (P and PHYP) could be easily gasified in a fluidized bed gasifier, thus producing a good quality gas with low polluting by-products. The PHYP sample showed lower tar content and higher gas yield. It is guessed that Ca and Mg, found in higher quantities in the PHYP sample, could have had a catalytic effect in tar reforming thus producing lower quantity of heavy hydrocarbons.

Black phosphorus intercalation compounds (BPICs) with alkali metals (namely: K and Na) have been synthesized in bulk by solid‐state as well as vapor‐phase reactions. By means of a combination of in situ X‐ray diffraction, Raman spectroscopy, and DFT calculations the structural behavior of the BPICs at different intercalation stages has been demonstrated for the first time. Our results provide a glimpse into the very first steps of a new family of intercalation compounds, with a distinct behavior as compared to its graphite analogues (GICs), showing a remarkable structural complexity and a dynamic behavior.

Mark-recapture methods constitute a set of classical ecological tools that are used to collect information on species dispersal and population size. These methods have advanced knowledge in disparate scientific fields, from conservation biology to pest control. Gathering information on the dispersal of mosquito species, such as Aedes aegypti, has become critical since the recognition of their role as vectors of pathogens. Here, we evaluate a method to mark mosquitoes that exploits the rare alkali metals rubidium (Rb) and caesium (Cs), which have been used previously to mark adult insects through feeding. We revised this method by adding Rb and Cs directly to water in which the immature stages of Ae. aegypti were allowed to develop. We then assessed the effect of Rb- and Cs-enriched water on fitness, survival and bioaccumulation in both adult females and their eggs. Results indicated that Cs had adverse effects on Ae. aegypti, even at low concentrations, whereas Rb at low concentrations had no measured effects on exposed individuals and accumulated at detectable levels in adult females. The method described here relies on passive uptake of Rb during immature stages, which has the benefit of avoiding handling or manipulation of the dispersive adults, which enables purer measurement of movement. Moreover, we demonstrated that Rb was transferred efficiently from the marked females to their eggs. To our knowledge, Rb is the only marker used for mosquitoes that has been shown to transfer vertically from females to eggs. The application of Rb rather than more traditional markers may therefore increase the quality (no impact on released individuals) and quantity (both adults and eggs are marked) of data collected during MR studies. The method we propose here can be used in combination with other markers, such as stable isotopes, in order to maximize the information collected during MR experiments.

Chemical reduction of OBO‐fused double[5]helicene with Group 1 metals (Na and K) has been investigated for the first time. Two doubly‐reduced products have been isolated and structurally characterized by single‐crystal X‐ray diffraction, revealing a solvent‐separated ion triplet (SSIT) with Na+ ions and a contact‐ion pair (CIP) with K+ ion. As the key structural outcome, the X‐ray crystallographic analysis discloses the consequences of adding two electrons to the double helicene core in the SSIT without metal binding and reveals the preferential binding site in the CIP with K+ counterions. In both products, an increase in the twisting of the double helicene core upon charging was observed. The negative charge localization at the central core has been identified by theoretical calculations, which are in full agreement with X‐ray crystallographic and NMR spectroscopic results. Notably, it was confirmed that the two‐electron reduction of OBO‐fused double[5]helicene is reversible., Adding extra twist: An increase in the twisting of the double helicene core upon addition of two electrons has been revealed in the crystallographically characterized solvent‐separated ion triplet (SSIT) and contact‐ion pair (CIP) products. The negative charge localization at the central core has been identified by theoretical calculations and supported by NMR spectroscopic results.

We describe the reversible intercalation of Na under graphene on Ir(1 1 1) by photo-dissociation of a previously adsorbed NaCl overlayer. After room temperature evaporation, NaCl adsorbs on top of graphene forming a bilayer. With a combination of electron diffraction and photoemission techniques we demonstrate that the NaCl overlayer dissociates upon a short exposure to an X-ray beam. As a result, chlorine desorbs while sodium intercalates under the graphene, inducing an electronic decoupling from the underlying metal. Low energy electron diffraction shows the disappearance of the moiré pattern when Na intercalates between graphene and iridium. Analysis of the Na 2p core-level by X-ray photoelectron spectroscopy shows a chemical change from NaCl to metallic buried Na at the graphene/Ir interface. The intercalation-decoupling process leads to a n-doped graphene due to the charge transfer from the Na, as revealed by constant energy angle resolved X-ray photoemission maps. Moreover, the process is reversible by a mild annealing of the samples without damaging the graphene., This work has been supported by the EU Graphene Flagship funding (Grant Graphene Core2 785219), the Spanish MINECO (MAT2017-85089-C2-1R) and the EU via the ERC-Synergy Program (Grant ERC-2013- SYG-610256 NANOCOSMOS) and the “Comunidad de Madrid” and European Structural Funds via FotoArt-CM project (P2018/NMT-4367).

International audience; Although dibenzyl disulfide (DBDS) is used as a mineral oil stabilizer, its presence in electrical transformer oil is associated as one of the major causes of copper corrosion and subsequent formation of copper sulfide. In order to prevent these undesirable processes, MY zeolites (with M = Li, Na, K, Cs, Cu or Ag) are proposed to adsorb molecularly DBDS. In this study, different MY zeolites are investigated at the DFT+D level in order to assess their ability in DBDS adsorption. It was found that CsY, AgY and CuY exhibit the best compromise between high interaction energies and limited S-S bond activation, thus emerging as optimal adsorbents for DBDS

Synergic combinations of alkali‐metal hydrocarbyl/amide reagents were used to synthesise saturated N‐heterocyclic carbene (NHC) ligands tethered to a fluorenide anion through deprotonation of a spirocyclic precursor, whereas conventional bases were not successful. The Li2 derivatives displayed a bridging amide between two Li atoms within the fluorenide‐NHC pocket, whereas the Na2 and K2 analogues displayed extended solid‐state structures with the fluorenide‐NHC ligand chelating one alkali metal centre.

The isolation and structural characterization of the cyanido‐substituted metalated ylides [Ph3P−C−CN]M (1‐M; M=Li, Na, K) are reported with lithium, sodium, and potassium as metal cations. In the solid‐state, most different aggregates could be determined depending on the metal and additional Lewis bases. The crown‐ether complexes of sodium (1‐Na) and potassium (1‐K) exhibited different structures, with sodium preferring coordination to the nitrogen end, whereas potassium binds in an unusual η 2‐coordination mode to the two central carbon atoms. The formation of the yldiide was accompanied by structural changes leading to shorter C−C and longer C−N bonds. This could be attributed to the delocalization of the free electron pairs at the carbon atom into the antibonding orbitals of the CN moiety, which was confirmed by IR spectroscopy and computational studies. Detailed density functional theory calculations show that the changes in the structure and the bonding situation were most pronounced in the lithium compounds due to the higher covalency.

In this study, we aimed to enhance the catalytic activity of perovskite catalysts and elucidate their catalytic behavior in the oxidative coupling of methane (OCM), using alkali-added LaAlO3 perovskite catalysts. We prepared LaAlO3_XY (X = Li, Na, K, Y = mol %) catalysts and applied them to the OCM reaction. The results showed that the alkali-added catalysts’ activities were promoted compared to the LaAlO3 catalyst. In this reaction, ethane was first synthesized through the dimerization of methyl radicals, which were produced from the reaction of methane and oxygen vacancy in the perovskite catalysts. The high ethylene selectivity of the alkali-added catalysts originated from their abundance of electrophilic lattice oxygen species, facilitating the selective formation of C2 hydrocarbons from ethane. The high COx (carbon monoxide and carbon dioxide) selectivity of the LaAlO3 catalyst originated from its abundance of nucleophilic lattice oxygen species, favoring the selective production of COx from ethane. We concluded that electrophilic lattice oxygen species play a significant role in producing ethylene. We obtained that alkali-adding could be an effective method for improving the catalytic activity of perovskite catalysts in the OCM reaction.

By exploring co-complexation reactions between the manganese alkyl Mn(CH2SiMe3)2 and the heavier alkali-metal alkyls M(CH2SiMe3) (M=Na, K) in a benzene/hexane solvent mixture and in some cases adding Lewis donors (bidentate TMEDA, 1,4-dioxane, and 1,4-diazabicyclo[2,2,2] octane (DABCO)) has produced a new family of alkali-metal tris(alkyl) manganates. The influences that the alkali metal and the donor solvent impose on the structures and magnetic properties of these ates have been assessed by a combination of X-ray, SQUID magnetization measurements, and EPR spectroscopy. These studies uncover a diverse structural chemistry ranging from discrete monomers [(TMEDA)2 MMn(CH2SiMe3)3] (M=Na, 3; M=K, 4) to dimers [{KMn(CH2SiMe3)3 ⋅C6 H6}2] (2) and [{NaMn(CH2SiMe3)3}2 (dioxane)7] (5); and to more complex supramolecular networks [{NaMn(CH2SiMe3)3}∞] (1) and [{Na2Mn2 (CH2SiMe3)6 (DABCO)2}∞] (7)). Interestingly, the identity of the alkali metal exerts a significant effect in the reactions of 1 and 2 with 1,4-dioxane, as 1 produces coordination adduct 5, while 2 forms heteroleptic [{(dioxane)6K2Mn2 (CH2SiMe3)4(O(CH2)2OCH=CH2)2}∞] (6) containing two alkoxide-vinyl anions resulting from α-metalation and ring opening of dioxane. Compounds 6 and 7, containing two spin carriers, exhibit antiferromagnetic coupling of their S=5/2 moments with varying intensity depending on the nature of the exchange pathways.

One of the most harmful compounds are nitrogen oxides. Currently, the common industrial method of nitrogen oxides emission control is selective catalytic reduction with ammonia (NH3-SCR). Among all of the recognized measures, NH3-SCR is the most effective and reaches even up to 90% of NOx conversion. The presence of the catalyst provides the surface for the reaction to proceed and lowers the activation energy. The optimum temperature of the process is in the range of 150–450 °C and the majority of the commercial installations utilize vanadium oxide (V2O5) supported on titanium oxide (TiO2) in a form of anatase, wash coated on a honeycomb monolith or deposited on a plate-like structures. In order to improve the mechanical stability and chemical resistance, the system is usually promoted with tungsten oxide (WO3) or molybdenum oxide (MoO3). The efficiency of the commercial V2O5-WO3-TiO2 catalyst of NH3-SCR, can be gradually decreased with time of its utilization. Apart from the physical deactivation, such as high temperature sintering, attrition and loss of the active elements by volatilization, the system can suffer from chemical poisoning. All of the presented deactivating agents pass for the most severe poisons of V2O5-WO3-TiO2. In order to minimize the harmful influence of H2O, SO2, alkali metals, heavy metals and halogens, a number of methods has been developed. Some of them improve the resistance to poisons and some are focused on recovery of the catalytic system. Nevertheless, since the amount of highly contaminated fuels combusted in power plants and industry gradually increases, more effective poisoning-preventing and regeneration measures are still in high demand.

An Embedded-Atom-Method model that is successful at describing the vibrational properties of alkali metals in the BCC crystal structure is applied to the HCP structure. Phonon dispersion curves, density of states, and Debye temperatures are calculalated for Li, Na, K, Rb, and Cs. Comparison of BCC, FCC and HCP Debye temperatures show that BCC is the preferred structure at higher temperatures, which agrees with experiment.

Pulsed excitation on the two-photon Cs 62S½ → 72D3/2,5/2 transition results in time-resolved fluorescence at 697 nm and 672 nm. The rates for fine structure mixing between the 72D3/2,5/2 states have been measured for helium and argon rare gas collision partners. The mixing rates are very fast, 1.26 ± 0.05 x 10-9 cm3/(atom sec) for He and 1.52 ± 0.05 x 10-10 cm3 /(atom sec) for Ar, driven by the small energy splitting and large radial distribution for the valence electron. The quenching rates are considerably slower, 6.84 ± 0.09 x 10-11 cm3 /(atom sec) and 2.65 ± 0.04 x 10-11 cm3 /(atom sec) for He and Ar, respectively. The current results are placed in context with similar rates for other alkali-rare gas collision pairs using adiabaticity arguments. Pulsed excitation on the two-photon Cs 6 2S1/2 → 8 2D3/2, 5/2 transition results in time-resolved fluorescence at 601 nm. The rates for fine structure mixing between the 8 2D3/2, 5/2 states have been measured for helium and argon rare gas collision partners. The mixing rates are very fast, 2.6 ± 0.2 x 10-9 cm3/(atom s) for He and 5.2 ± 0.4 x 10-10 cm3/(atom s) for Ar, about 2-3 times faster than for the Cs 7 2D5/2 ↔ 7 2D3/2 relaxation. The quenching rates are also rapid, 1.07 ± 0.04 x 10-10 cm3/(atom s) and 9.5 ± 0.7 x 10-11 cm3/(atom s) for He and Ar, respectively. The rapid fine structure rates are explained by the highly impulsive nature of the collisions and the large average distance of the valence electron from the nucleus. Quenching rates (intermultiplet transfer) are likely enhanced by the closely spaced, 9 2P levels. Stimulated emission on the ultraviolet and blue transitions in Cs has been achieved by pumping via two-photon absorption for the pump transition 62S 1/2 → 72D5/2,3/2. The performance of the optically-pumped cesium vapor laser operating in ultraviolet and blue has been extended to 650 nJ/pulse for 387 nm, 1.3 µJ/pulse for 388 nm, 200 nJ/pulse for 455 nm and 500 nJ/pulse for 459 nm. Emission performance improves dramatically as the cesium vapor density is increased and no scaling limitations associated with energy pooling or ionization kinetics have been observed.

Article The increasing demand for biofuels leads to a growing need for agromass, such as herbaceous plants and agricultural waste. However, agromass contains high quanitites of alkali metals, mainly potassium and sodium, which limits agromass usage in thermoconversion processes. Alkali metals react with other ash forming elements which leads to ash related problems such as agglomeration, fouling and slagging during agromass burning. In this study, chemical composition and melting behaviour of ashes form ed at 550 ° C are investigated. Three herbaceous plants (reed canary grass, hemp, orchard grass), four types of agricultural waste (straws of rye, wheat, buckwheat and canola) and two types of woody biomass (birch, spruce) are selected. Ash melting behaviou r, composition and bulk structure are determined using a high temperature furnace with a video camera, inductively coupled plasma atomic emission – spectrometry and X – ray diffraction technique, respectively . Ash melting behaviour of selected agromass types s hows that the hemp ash has the highest shrinkage starting temperature which reaches 1 , 079 °C. This is due to the high content of calcium and low content of potassium and sodium in hemp ash. T hree main components calcium carbonate, potassium sulfate and pot assium chloride have been identified in ashes after agromass and woody biomass are heat – treated at temperature of 550 °C.

Embedded-atom-method models have been used in the calculation and prediction of many vibrational and thermal properties of materials. In 2012 Wilson and Riffe constructed a model that predicts dispersion relations and frequency-moment Debye temperatures of the alkali metals with a greater degree of accuracy than previous models. The Wilson-Riffe model was implemented using MATLAB code. Here that model is extended to model alkali metals in the close-packed fcc structure. Code development is discussed, and results are presented for dispersion relations, density of states, Debye temperatures and free energy. The vibrational free energy combined with a suitable constant representing the electronic free energy of these metals is found to be the driving factor in the phase transition to close-packed structures that occurs in Lithium and Sodium at low temperatures.

The element lithium has been discovered 200 years ago. Due to its unique properties it has emerged to play a vital role in industry, esp. for energy storage, and lithium‐based products and processes support sustainable technological developments. In addition to the many uses of lithium in its inorganic forms, lithium has a rich organometallic chemistry. The development of organometallic chemistry has been hindered by synthetic problems from the start. When Wilhelm Schlenk developed the basic principles to handle and synthesize air‐ and moisture‐sensitive compounds, the road was open to further developments. After more information was available about the stability and solubility of such compounds, they started to play an essential role in other fields of chemistry as alkyl or aryl transfer reagents.

An effective and facile method has been developed to reduce graphene oxide (GO) in alkyl amine solution using alkali metal as reducing agent. The alkali metal donates electrons to the GO and the oxygen-containing functional groups were eliminated to produce high-quality reduced graphene oxide (RGO). ASTAR (Agency for Sci., Tech. and Research, S’pore)

Cesium fluorides in ionic liquid [bmim][BF4] have been used to promote the Henry reaction effectively. These reactions proceed smoothly and afford an excellent yield of the products.