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ABSTRACT Solid complexes of tolfenamic acid (tolfH) with Mg(II), Ca(II), Sr(II), and Ba(II) have been synthesized and characterized by CHN, metal contents analysis, FTIR, UV, 1H‐NMR spectroscopy, thermal (TGA, DTG, DTA, and DSC) analysis, molar conductance, powder X‐ray diffraction (XRD), and scanning electron microscopy (SEM–EDX). Based on these studies, the probable formulae for the complexes are [Mg(tolf)Cl(H2O)3].4H2O, [Ca(tolf)2(H2O)2], [Sr2(tolf)4(H2O)4], and [Ba2(tolf)4(H2O)4]. The ligand tolfenamate ion (tolf) exhibited different modes of coordination, including bidentate and chelating. The 1H‐NMR displayed the presence of tolfenamato ions in the coordination sphere, the purity and stability of the complexes in solution. The average crystallite sizes of the complexes were determined by XRD and ranged from 55 to 70 nm. SEM micrographs showed the rod‐ or plate‐like morphology of the prepared complexes. The complexes showed promising antioxidant activity in the DPPH radical scavenging method, with an IC50 value of 12–15 μg/mL. Against gram‐positive and gram‐negative bacteria, as well as fungi, the metal complexes also demonstrated significant antimicrobial activity. In the brine shrimp lethality bioassay, the metal complexes exhibited significantly highest cytotoxicity with the range of 15.25–24.57 μg/mL. All the complexes showed cytotoxicity against human cervical carcinoma HeLa cell lines, while the ligand itself did not show any cytotoxicity to these cancer cells. Furthermore, the metal complexes exhibited improved central and peripheral analgesic activity compared to tolfenamic acid. [ABSTRACT FROM AUTHOR]

The cost‐effectiveness and environmentally friendly nature of aqueous zinc‐ion batteries (ZIBs) have garnered significant attention. Nevertheless, obstacles such as dendrite growth and side reactions have hindered their practical application. Here, an alkaline earth metal ion, strontium ions (Sr2+), is chosen as a dual‐functional electrolyte additive to improve the reversibility of ZIBs. Importantly, Sr2+ ions adsorb on the anode surface, creating a dynamic electrostatic shield layer, thus regulating the Zn2+ deposition behavior and suppressing side reactions. Meanwhile, Sr2+ ions prefer to adsorb on (002) and (110) planes of Zn, thus inducing the preferential deposition of (100) crystal plane and achieving dendrite‐free zinc anode. Consequently, the assembled Zn||Zn symmetric battery delivers an ultralong lifespan of 3500 h, and the Zn||Ti asymmetric battery shows a superior Coulombic efficiency of 99.8% for Zn stripping/plating at 2 mA cm−2. Further, the Zn||NH4V4O10 battery presents an excellent retention of 97.7% over 800 cycles under 2 A g−1. This research introduces a novel alkaline earth metal ion electrolyte additive and establishes its persistent dynamic electrostatic shielding effect and preferentially oriented (100) plane plating, ensuring dendrite‐free zinc deposition. These findings chart a course for further exploration of unexplored alkaline earth elements in enhancing metal battery technologies. [ABSTRACT FROM AUTHOR]

Acrylates/acrylic acid are important for polymer industry due to its very high volume applications in different sectors. Activity of Ba/Mg modified hydroxyapatite for vapour-phase dehydration of ammonium lactate with 100% conversion and 60% acrylate selectivity was attributed to fine tuning of acid/base properties and formation of surface Ba/Ca lactate species. [ABSTRACT FROM AUTHOR]

In this work, different alkaline earth metals intercalated into g-C3N4 (MCN, M = Ca, Sr, Ba) were prepared through the calcination of alkaline earth metal chlorides (MCl2, M = Ca, Sr, Ba) and melamine. The crystallite sizes of Bulk CN, BaCN, SrCN, and CaCN are 4.6, 4.8, 1.9, and 1.5 nm, respectively. In order to efficiently transfer charges among the g-C3N4 layers, the alkaline earth metal ions were designed as a "bridge", which could chemically bond with the atoms of two adjacent layers while connecting the upper and lower layer. It is found that the cyano groups appearing on the MCN skeleton have a strong electron-attracting effect, which has a good guiding effect on promoting the separation of electrons and holes. The results of density functional theory further confirmed that BaCN had the strongest adsorption energy for peroxymonosulfate. Experiment results showed that the BaCN photocatalyst exhibited an excellent bisphenol A (BPA) degradation activity in the presence of peroxymonosulfate. The results showed that the performance of the BaCN photocatalyst to degrade BPA under visible light was 12 times that of CN. Meanwhile, the BaCN photocatalyst still had a 95% efficiency of BPA removal after four cycles of the experiment. The possible reaction mechanism in the degradation process was analyzed through electron spin resonance and capture experiments. This paper provides an idea for the comodification of g-C3N4 with alkali earth metals and cyanide groups to activate peroxymonosulfate. [ABSTRACT FROM AUTHOR]

BackgroundAn electrolyte waste salt containing LiCl and various products is generated during the pyroprocessing of spent nuclear fuel in metal fast reactors. Separating metal impurities from waste salt can purify molten salt, facilitate salt recycling, and reduce the amount of waste salt, achieving waste minimization.PurposeThis study aims to investigate the effects of key factors on the application of the cold finger crystallization method used for removal of Sr and Ba from molten LiCl salt.MethodsA homemade cold finger experimental apparatus was applied to the experimental removal of two alkaline earth metals, Sr and Ba, from molten LiCl salt, and Fluent software was employed to simulate the application of cold finger crystallization equipment during dry reprocessing. The effects of crystal growth time, initial crystallization temperature, and initial SrCl2/BaCl2 concentrations on the removal ratio of the crystalline salt during the process were analyzed.ResultsThe initial temperature of molten salt is a critical factor that influences cold finger separation efficiency. When the initial temperature reaches 660 ℃, the removal efficiency improves. Moreover, when the impurity contents of Sr and Ba in molten salt are lower than 0.55%(w/w), the removal efficiency of the cold finger crystallization method can exceed 80%. Further analysis shows that the removal effects of different parts of molten salt crystals differ. The solvent salt at the top of the molten salt crystal is better, and the removal ratio of the bottom and inner salts is lower. Therefore, the optimal conditions for removing Sr and Ba from LiCl crystalline salt require an initial temperatures of 660~670 ℃, an airflow intensity of 10 L·min-1, and a growth time of 20 min. Under these optimal conditions, the removal ratio can reach 90%.ConclusionsThe proposed approach is feasible for purifying solvent salts from electrolyte waste molten salt via cold finger crystallization. This study provides a reference for purifying waste salt and reusing molten salt.

A series of CaF2:Yb3+/Er3+ nanoparticles were prepared by thermal decomposition method, the NIR-II luminescence performance were optimized through changing the doping concentration of Yb3+ and Er3+. The result shows that when the doping concentration of Yb³+ is 20%, and that of Er³+ is 2%, the NIR-II luminescence performance is best excited by a 980 nm light source. The nanoparticles also have a good dispersion and the size is uniform. Different alkaline earth metal ions（Li+, Na+, K+） co-doped were further studied. The result indicates that the co-doping of K+ or Na+ are both in favor of the promotion of NIR-II luminescence performance. Instead, the NIR-II luminescence goes down after the Li+ co-doping, because the nanoparticles cannot nucleate well. Compared with the Na+, the ionic radius of K+ is larger, which is conducive to break the local symmetry of the crystal field. Therefore, the NIR-II luminescence performance is best after the K+ co-doping. [ABSTRACT FROM AUTHOR]

Activation of dinitrogen (N2) is the critical step in nitrogen reduction reaction (NRR) in ammonia synthesis. In this paper, reaction mechanisms of N2 activation on trimetallic clusters Mo2M (M = Li, Na, K, Mg, and Ca) and Mo3−xCax (x = 2–3) were systematically studied by density functional theory calculations. Unlike Mo2 which is inert to N2, clusters with alkali or alkaline earth metal atoms have much higher reactivity toward N2 in terms of both thermodynamics and kinetics. Particularly, in one reaction path of N2 with MoCa2, all the intermediates and transition states are well below the energy sum of the reactants, indicating that the dissociation of N2 on MoCa2 can take place spontaneously in gas-phase reactions. N2 transfers on clusters with different coordination modes, and the N−N bond is gradually activated. When N2 is bonded with three metal atoms with end-on: side-on: side-on coordination mode, it is fully activated and easily dissociated into two adsorbed N atoms. These results may serve as a prototype to design single-cluster catalysts with a trimetallic center for nitrogen activation and conversion. [ABSTRACT FROM AUTHOR]

γ-Fe2O3 has an excellent low-temperature selective catalytic reduction (SCR) deNOx performance, but its resistance to alkaline earth metal calcium (Ca) is poor. In particular, the detailed mechanism of Ca poisoning on the γ-Fe2O3 catalyst at the atomic level is not clear. Hence, the density functional theory method was used in this research to investigate the influence mechanism of Ca poisoning on the NH3-SCR over the γ-Fe2O3 catalyst surface. The findings reveal that NH3, NO, and O2 molecules can bind to the γ-Fe2O3 (001) surface to generate coordinated ammonia, monodentate nitroso, and adsorption oxygen species, respectively. The main active site is Fe1-top. For the γ-Fe2O3 with Ca poisoning, the Ca atom has a high adsorption energy on the surface of γ-Fe2O3 (001), which covers the catalyst surface and reduces the active sites. The presence of Ca atom decreases the adsorption performance of NH3, while slightly improving the NO and O2 adsorption. In particular, the Ca atom restrains the NH3 activation and NH2 formation, which is detrimental to the NH3-SCR process. [ABSTRACT FROM AUTHOR]

Heterogeneous photocatalysis rarely employs main group metals as active centers due to the lack of available d orbitals. In this study, alkaline earth metal centers were introduced into a carbon-doped boron nitride framework, leading to an optimization of their electronic structure and successful activation of catalytic activity. Interestingly, these metal centers were found to effectively utilize d orbitals or d/p hybrid orbitals to activate O 2 and H 2 O, thereby generating a wealth of reactive oxygen species (ROS), which efficiently convert NO to NO 3 -. In addition, the optimized alkaline earth metal structural unit can not only strengthen carrier separation, but also improve the adsorption behavior of NO 2 on the catalyst surface and promote its further conversion to NO 3 -. This research provides new insights into the design of highly active sites and the exploration of catalytic mechanisms for alkaline earth metals. [Display omitted] ● Novel Ca/Sr-coordinated C-BN catalysts boost NO to NO 3 - conversion efficiency. ● Enhanced charge separation and ROS production via Ca/Sr integration identified. ● Achieved >97% selectivity for NO 3 - with trace NO 2 emission in photocatalysis. ● Offers insights for developing high-performance NO oxidation photocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • [(C 6 H 12 O 6)Ag-X 3 -Ag(C 6 H 12 O 6)] (X=Be, Mg) complexes are modelled using FMO approach. • Be 3 and Mg 3 cores are electron deficient in [(C 6 H 12 O 6)Ag-X 3 -Ag(C 6 H 12 O 6)] (X=Be, Mg). • Ag-Be and Ag-Mg contacts in [(C 6 H 12 O 6)Ag-X 3 -Ag(C 6 H 12 O 6)] (X=Be, Mg) are partially covalent. • Be 3 and Mg 3 cores in [(C 6 H 12 O 6)Ag-X 3 -Ag(C 6 H 12 O 6)] (X=Be, Mg) exhibit aromatic property. Seeing the frontier molecular orbitals (FMO) picture of β- d -glucopyranose–silver+ (1:1) complex ([Ag(C 6 H 12 O 6)]+) reported in a recent article (Mondal, 2024) [53], we used the FMO based approach to obtain inverted sandwich like organometallic complex comprising X 3 (X=Be, Mg) core, in silico. Thermodynamic feasibility of obtaining [(C 6 H 12 O 6)Ag-X 3 -Ag(C 6 H 12 O 6)] (X=Be, Mg) complexes are explored. Conceptual density functional theory (CDFT) based reactivity descriptors guide to ascertain the stability order of such complexes. By the help of natural bond orbital analysis, Wiberg bond indices (WBI), bond critical point analysis, electron density descriptors, and gradient isosurface between selected contacts, the nature of interaction between the X 3 core and Ag metals are studied. FMO of the complexes further help in ascertaining the nature of binding. Energy decomposition analysis marks the interaction between X 3 and Ag metals in [(C 6 H 12 O 6)Ag-X 3 -Ag(C 6 H 12 O 6)] (X=Be, Mg) as partially covalent. Negative values of nucleus independent chemical shift (NICS) at the triangular ring (X 3) centres [NICS(0)] indicate aromatic property. [ABSTRACT FROM AUTHOR]

In analyzing the effect of alkali metal and alkaline earth metal oxide on the properties of tellurite glass, a series of tellurite glass samples doped with alkali metals and alkaline earth metals were prepared based on the TeO 2 -WO 3 -GdF 3 glass system by melt quenching method. Through tests and comprehensive analysis, the results show that after the F− ions successfully enter the glass network, the substitution of TeO 2 by alkali and alkaline earth metals could reduce the molar volume, which means the glass becomes more compacted. The influence on the glass network is mainly shown in [TeO 3 ] and [TeO 4 ] units. Alkali metals and alkaline earth metals could increase the asymmetry of the TWG: Eu3+ glass network, shorten the critical distance, and increase luminescence intensity by 8.6 times and improve color purity to 94%. In addition, alkali metals could prolong the fluorescence lifetime, while alkaline earth metals could shorten it. Te4+ [ABSTRACT FROM AUTHOR]

Two quaternary alkaline earth metal sulfides, BaCu 6 Ge 2 S 8 (1) and BaCuAsS 3 (2), were synthesized under low-temperature solvothermal conditions. Compound 1 features a three-dimensional (3D) [Cu 6 Ge 2 S 8 ] n 2n- framework comprising CuS 3 , CuS 4 , and GeS 4 units, with Ba2+ cations occupying the channels. Compound 2 exhibits a one-dimensional (1D) chained structure, with Ba2+ cations situated between the chains. Alkaline earth metal ions exhibit a structural directing effect that is distinct from that of other guest cations. Specifically, Compound 1 presents a rare instance of a 3D Cu-Ge-S framework formed by condensation of two parallel layers. Compound 2 is the first 1D A-Cu-As-S compound (where A represents guest cations). Additionally, compound 2 presents the first example of AⅡ-Cu-As-S (where AⅡ represents alkaline earth metal cations) compounds. Their optical properties and theoretical calculations were also investigated. Our results demonstrate that solvothermal synthesis is a promising method for obtaining multinary alkaline earth metal sulfides with diverse structures and properties. [Display omitted] • Two quarternary alkaline earth metal sulfides were prepared using the low-temperature solvothermal method. • The solvothermal method reduces the synthesis temperature and is beneficial for obtaining thermodynamic metastable phases. • Compound 2 presents the first example of AⅡ-Cu-As-S (AⅡ = alkaline earth metal cations). [ABSTRACT FROM AUTHOR]

The addition of appropriate promoters can modulate the chemical characteristics of heterogeneous catalysts so as to improve and optimize their catalytic performance. Here, we introduced SrO as both a support and a promoter to optimize the activity of Ni/La 2 O 3 -based catalysts for the ammonia decomposition reaction. A series of La 1−x Sr x NiO 3-δ -600H 2 catalysts were prepared by reducing La 1−x Sr x NiO 3-δ (x = 0, 0.2, 0.33, 0.5, 0.67, 0.8, and 1) precursors under a H 2 /N 2 atmosphere. The La 0.5 Sr 0.5 NiO 3-δ -600H 2 catalyst with a proper amount of Sr exhibited outstanding ammonia decomposition conversion rate (87.7%) and hydrogen production rate (29.4 mmol·g cat −1·min−1) at 550 °C with a GHSV of 30,000 mL·g cat −1·h−1. The presence of Sr induced the Ni species to be situated in a more electro-negative environment, thus facilitating the recombination of N atoms and N 2 desorption; whereas Ni nanoparticles could be evenly dispersed by La 2 O 3 , which rendered the catalyst with high stability. Briefly, the synergistic effect of Sr increasing electron density of Ni species and La 2 O 3 stabilizing Ni nanoparticles has greatly enhanced the catalytic performance. This work has demonstrated a new variety of promising noble metal-free catalysts toward the eventual application in hydrogen production from ammonia decomposition reaction. [Display omitted] • Catalysts of Ni/La 2 O 3 with SrO as a promoter were prepared by reducing La 1−x Sr x NiO 3-δ derived from a sol-gel method. • The catalyst with a proper amount of Sr (LaSr = 1:1) exhibited outstanding ammonia decomposition performance. • Sr increasing Ni species electron density along with La 2 O 3 stabilizing Ni nanoparticles enhanced the catalytic performance. [ABSTRACT FROM AUTHOR]

The mesoporous alumina-supported alkaline earth metal 5 M/MA (MA= mesoporous alumina, M=Mg, Ca, Sr, and Ba) and x Mg/MA (x =1, 3, 5, and 7 wt%) adsorbents were synthesized via evaporation-induced self-assembly (EISA) and impregnation method. The adsorption properties of CO 2 were evaluated by thermal gravimetric analyzer to focus on exploring the dynamic adsorption process of the prepared adsorbents. Loading alkaline earth metals mainly enhanced the basic sites of these adsorbents, and the alkaline sites played an extremely critical role in determining the amount of CO 2 adsorbed. Of all the adsorbents prepared, 5Mg/MA exhibited the highest adsorption uptake (1.08 mmol/g), a 2.16-fold enhancement compared to MA (0.50 mmol/g). In-situ DRIFTS indicated that CO 2 primarily existed in the form of carbonate species, and the analysis of adsorption kinetics elucidated that the adsorption process was predominantly chemisorbed, with external diffusion being the main process of adsorption. Simultaneously, based on DFT calculations, it has been found that Mg-loaded MA has a higher affinity for CO 2 compared to MA, which providing a good explanation for the experimental results. Furthermore, the 5 Mg/MA adsorbent not only exhibited excellent adsorption capacity, but also maintained excellent cyclic stability after 10 adsorption and desorption cycle runs, making it a highly favorable option for capturing CO 2. [Display omitted] • The addition of alkaline earth metals primarily increased basic sites. • In-situ DRIFTS revealed that CO 2 was primarily present as carbonate species. • 5Mg/MA exhibited excellent adsorption performance and recycling stability. • Adsorption kinetics analysis manifested 5Mg/MA was predominantly chemisorbed. • DFT validated Mg/MA has a higher affinity for CO 2 compared to MA. [ABSTRACT FROM AUTHOR]

The cationic benzyl complex [(Me4TACD)Sr(CH2Ph)][A] (Me4TACD=1,4,7,10‐tetramethyltetraazacyclododecane; A=B(C6H3‐3,5‐Me2)4) reacted with two equivalents of phenylsilane to give the bridging hexahydridosilicate complex [(Me4TACD)2Sr2(thf)4(μ‐κ3 : κ3‐SiH6)][A]2 (3 a). Rapid phenyl exchange between phenylsilane molecules is assumed to generate monosilane SiH4 that is trapped by two strontium hydride cations [(Me4TACD)SrH(thf)x]+. Complex 3 a decomposed in THF at room temperature to give the terminal silanide complex [(Me4TACD)Sr(SiH3)(thf)2][A], with release of H2. Upon reaction with a weak Brønsted acid, CO2, and 1,3,5,7‐cyclooctatetraene SiH4 was released. The reaction of a 1 : 2 mixture of cationic benzyl and neutral dibenzyl complex with phenylsilane gave the trinuclear silanide complex [(Me4TACD)3Sr3(μ2‐H)3(μ3‐SiH3)2][A], while nOctSiH3 led to the trinuclear (n‐octyl)pentahydridosilicate complex [(Me4TACD)3Sr3(μ2‐H)3(μ3‐SiH5nOct)][A]. [ABSTRACT FROM AUTHOR]

Electronic circular dichroism (ECD) and anisotropy spectra carry information on differential absorption of left‐ and right‐circularly polarized light (LCPL and RCPL) by optically active compounds. This makes them powerful tools for the rapid determination of enantiomeric excesses (ee) in asymmetric synthetic and pharmaceutical chemistry, as well as for predicting the ee inducible by ultraviolet (UV) CPL. The ECD response of a chiral molecule is, however, critically dependent on the properties of the surrounding medium. Here, we report on the first ECD/anisotropy spectra of aqueous solutions of the calcium salt dihydrate of glyceric acid. A systematic study of the effect of the salt concentration and pH on the chiroptical response revealed significant changes and the appearance of a new ECD band of opposite sign. Based on the literature, this can be rationalized by the increase in the relative proportion of free glyceric acid/glycerate to Ca2+ complexes with glycerate with decreasing salt concentration or pH. Glyceric acid can be readily produced under astrophysical conditions. The anisotropy spectra of the solution containing prevalently the free form of this dihydroxy carboxylic acid resemble the ones of previously investigated aliphatic chain hydroxycarboxylic acids and proteinogenic amino acids. This indicates possible common handedness of stellar CPL‐induced asymmetry in the potential comonomers of primitive proto‐peptides. [ABSTRACT FROM AUTHOR]

The CO2 gasification of South Open-pit Mines coal from Zhundong field of China using Ca(OH)2 or K2CO3 as catalyst with different loading methods and contents were conducted in thermogravimetric analysis. Comparison of the gasification reactivity and rate of coal loaded various concentration of Ca(OH)2 concluded that the increase of Ca(OH)2 loading pronouncedly improved the reactivity and rate for grinding method, nevertheless, for impregnation and high pressure method the increase of Ca(OH)2 loading observed a similar catalytic effect on char gasification. However, the catalytic effect of K2CO3 revealed that the catalytic activity increased with the increase of K2CO3 loading for three loading method. For the same catalyst loading, the highest catalytic gasification reactivity achieved for Ca(OH)2 and K2CO3 were the loading methods of high pressure and grinding, respectively. In addition, the gasification of raw char, KJZO3 loaded char and Ca(OH)2 loaded char were quantitatively evaluated by kinetic analysis using shrinking core, random pore and modified random pore models. [ABSTRACT FROM AUTHOR]

In this study, the direct conversion behaviors of different alkaline earth metal solids (the hydroxides and the sulfates of alkaline earth metals Ca, Sr, Ba and Mg) to their corresponding carbonates in dissolved carbonate-containing pregnant solutions obtained by direct leaching of a smithsonite (ZnCO3) ore sample in aqueous ammonia solutions having different concentrations (4 M, 8 M and 13.3 M NH3) were investigated by using X-ray diffraction analyses at alkaline earth metal to dissolved carbonate mole ratios of 1:1 and 1:2, for revealing the conversion possibilities of dissolved carbonate in the pregnant solutions to solid carbonate by-products. The results of direct conversion experiments showed that Ca(OH)2, CaSO4·2H2O, Sr(OH)2·8H2O and Ba(OH)2·8H2O converted to their corresponding carbonates, SrSO4 partially converted to SrCO3 as observed by the presence of unreacted SrSO4 peaks in X-ray diffraction patterns of the converted solids, and BaSO4 did not convert to BaCO3 because of its lower solubility with respect to BaCO3. On the other hand, it was observed that Mg(OH)2 did not convert to MgCO3, but MgSO4·7H2O converted dominantly to an uncommon phase, which was tentatively identified as Mg5Zn3(CO3)2(OH)12·H2O. In the study, a complete discussion on the conversion behaviors of alkaline earth metal solids to their corresponding carbonates was given considering the differences between their solubility product constants and the changes in the free energies of the theoretical conversion reactions. In addition, infrared spectra and scanning electron microscope images of some of the converted solids were also presented for characterization purposes. [ABSTRACT FROM AUTHOR]

Although numerous efforts have been made in direct syngas conversion to higher alcohols via Fischer–Tropsch synthesis, the higher alcohols distribution remains a challenge. Here, we introduce alkaline earth metal oxide as promoter into activated carbon supported cobalt catalyst to tune distribution of higher alcohols. With the addition of Mg, the distribution of C2-5 alcohols increase from 41.2 to 75.8% accompanying with distribution of C6-18 alcohols decrease from 52.8 to 14.0%. Ba-promoted Co based catalyst (CoBa/AC) presents similar alcohols distribution to un-promoted catalyst, while the alcohol selectivity over CoBa/AC is higher than Co/AC. For promoted catalysts, the distribution of C6-18 alcohols increased in the order of Mg < Ca < Sr < Ba. The characterization results exhibit that the promoter addition facilitates the cobalt carbide formation, which leads to enhancement of selectivity to higher alcohols. The available active cobalt sites of promoted Co based catalysts increase in the same above order of Mg < Ca < Sr < Ba. [ABSTRACT FROM AUTHOR]

Reaction of a MgN"2/BaN"2 mixture (N"=N(SiMe3)2) with PhSiH3 gave three unique heterometallic Mg/Ba hydride clusters: Mg5Ba4H11N"7 ⋅ (benzene)2 (1), Mg4Ba7H13N"9 ⋅ (toluene)2 (2) and Mg7Ba12H26N"12 (3). Product formation is controlled by the Mg/Ba ratio and temperature. Crystal structures are described. While 3 is fully insoluble, clusters 1 and 2 retain their structures in aromatic solvents. DFT calculations and AIM analyses indicate highly ionic bonding with Mg−H and Ba−H bond paths. Also unusual H−⋅⋅⋅H− bond paths are observed. Catalytic hydrogenation with MgN"2, BaN"2 and the mixture MgN"2/BaN"2 has been studied. Whereas MgN"2 is only active in imine hydrogenation, alkene and alkyne hydrogenation needs the presence of Ba. The catalytic activity of the MgN"2/BaN"2 mixture lies in general between that of its individual components and strong cooperative effects are not evident. [ABSTRACT FROM AUTHOR]

Three new layered mixed metal phosphonates [CoMg(notpH2)(H2O)2]ClO4·nH2O (CoMg·nH2O), [Co2Sr2(notpH2)2(H2O)5](ClO4)2·nH2O (CoSr·nH2O), and [CoBa(notpH2)(H2O)1.5]ClO4 (CoBa) were synthesized by reacting a tripodal metalloligand CoIII(notpH3) [notpH6 = C9H18N3(PO3H2)3] with alkaline earth metal ions. Along with an increase in the radius of the alkaline earth metal ions, the 6-coordinate {MgO6}, 7-coordinate {SrO7}, and 9-coordinate {BaO9} geometries are the distorted octahedron, capped triangular prism, and tricapped triangular prism, respectively. Consequently, the metalloligand Co(notpH2)− adopts variable coordination modes to bind the alkaline earth metal nodes, forming diverse layer topologies in the three mixed metal phosphonates. The AC impedance measurements revealed that the proton conductivities at 25 °C and 95% relative humidity (RH) follow the sequence: CoMg·nH2O > CoSr·nH2O > CoBa. As expected, CoMg·nH2O exhibits a 28-fold enhanced value for proton conductivity (4.36 × 10−4 S cm−1) compared with the previously reported isostructural compound, CoCa·nH2O, at 25 °C and 95% RH due to the greater Lewis acid strength of Mg(II) lowering the pKa of the coordinated water.

A new sodium rubidium strontium borate, Na2Rb2SrB18O30, has been successfully synthesized via the high temperature solution method and characterized by single crystal X ray diffraction. The compound crystallizes in the monoclinic space group P21/c (No. 14) with the following cell parameters: a=8.464(5) Å, b=8.516(5) Å, c=17.110(10) Å, β=92.281(8)°, V=1232.3(12) Å3, Z=2. The fundamental building block (FBB) of Na2Rb2SrB18O30 is [B9O19]11−, which consists of three [B3O7]5− groups bridged by oxygen atoms. The FBB connects with adjacent ones through the terminal oxygen atoms condensed into a three dimensional (3D) 3∞[B9O15] network with three types of channels, and two of them are occupied by Rb+ and Sr2+ cations. Besides, the structure comparison and categorization between the borates with [B9O19]11− FBB were investigated via the topological analysis for the first time. Also, theoretical analyses of the band structures and partial densities of states (PDOS) calculations were carried out to elaborate the relationship between crystal structures and optical properties by first‐principles calculation. [ABSTRACT FROM AUTHOR]

Biodegradable polyesters such as poly(ϵ‐caprolactone) (PCL) and poly(lactic acid) (PLA) have been considered for use in several areas, such as drug delivery devices, sutures, tissue engineering, and GBR membranes, due to its bio‐renewability, biodegradability, and biocompatibility. Several synthetic techniques for the preparation of polyesters have been reported in the literature, amongst which the ring‐opening polymerization (ROP) of cyclic esters is the most efficient. A convenient approach to access iso‐selective PLAs is polymerization of racemic lactide (rac‐LA), which shows excellent stereoregularity without the need for costly chiral auxiliaries or ligands. In this personal account, we review a series of methods that have been practiced to the synthesis of biodegradable polyesters from various cyclic monomers using alkali and alkaline earth metal complexes as efficient catalysts. [ABSTRACT FROM AUTHOR]

Density Functional Theory (DFT) calculations were performed to investigate the adsorption of alkali and alkaline earth metal ions, Na+, K+, Mg2+, and Ca2+ present in seawater by biopolymers, cellulose, chitosan, and chitin. Analysis of the optimized geometries of the complexes formed by physisorption of metal ions on biopolymers reveals that monomer of chitin is the best biopolymer for adsorption of Mg2+ ion. Water as a solvent reduces the reactivity of complexes formed, playing a significant role in complex stability, which further proved the effective use of cellulose, chitosan and chitin for real-time applications. Natural Bond Orbital (NBO) analysis and quantum reactivity descriptors of the optimized geometries indicate that the electronic charge transfer between the biopolymer and metal ions acts as a driving force for the complex formation. This study also highlights the significant role of water in physisorption of metal ions on biopolymer. [Display omitted] • Adsorption of alkali and alkali earth metal ions, Na+, K+, Mg2+, and Ca2+ present in seawater by biopolymers, cellulose, chitosan, and chitin, were investigated. • Chitin is the best biopolymer for adsorption of Mg2+. • Electronic charge transfer between the monomer and metal ions acts as a driving force for the complex formation. • Water as a solvent plays a significant role in complex stability. [ABSTRACT FROM AUTHOR]

With the exception of beryllium, divalent cations of every alkaline earth metal are characterized by their calcimimetic behavior. Thus, in vivo biodistribution of these cations mostly occurs in form of a massive accumulation in bone tissues, consisting of hydroxyapatite to a major extent. Apart from the lightest elements beryllium and magnesium, animal studies and human studies regarding the overall in vivo behavior were carried out by using radioisotopes of the elements calcium, strontium, barium and radium. To date, only strontium with its radioisotopes and radium gained importance for applications in nuclear medicine, mainly for pain-reducing and palliative treatment of bone metastases. In contrast, barium radioisotopes can be ascertained as useful imaging agents and possible diagnostic analogues for theranostic approaches. This review focuses on the characteristic and chemical behavior of barium compounds, possible radioactive barium isotopes for future applications in nuclear medicine and radiopharmacy as well as recent results regarding barium-131 as diagnostic match for radium isotopes used in targeted alpha therapy. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract This work evaluated the effects of inherent alkali and alkaline earth metals on nitrogen transformation during steam gasification of Shengli lignite at the temperature of 873–1173 K in a fluidized-bed/fixed-bed quartz reactor. The results indicated that the alkali metal Na and alkaline earth metals Ca, Mg in coal have different effects on inherent nitrogen transformation to NH3, HCN and char-N during the lignite steam gasification. Specifically during the steam gasification of Shengli lignite, Na and Ca, Mg not only catalyze the inherent nitrogen conversions to NH3, but also promote the secondary reactions of the nascent char-N as well as the generation of NH3 from the generated HCN, meanwhile they also inhibited the inherent nitrogen conversion to HCN and char-N. The presence of Na, Ca and Mg hindered the formation of oxidized nitrogen (N-X) functional groups, but enhanced pyridinic nitrogen (N-6) and quaternary nitrogen’s (N-Q) formation in char.

A systematic study of the systems M2+/H4L/KOH/H2O, with M2+ =Mg2+, Ca2+, Sr2+, Ba2+ and H4L=N,N'-4,4'-bipiperidine-bis (methylenephosphonic acid) was carried out using highthroughput methods, including a temperature gradient oven. Overall, six new alkaline earth phosphonates were discovered and structurally characterised by single-crystal and powder Xray diffraction. At room temperature the compounds of composition [Mg2(H2O)8(L)] (1), [Ca2(H2O)6(L)] (2), [Sr2(H2O)4(L)] (3) and [Ba2(H2O)9(L)]·H2O (4) were discovered. They exhibit the same metal to linker ratio, but differ in their water content. Distinct structural changes are observed with an increase in dimensionality of the coordination polymer with increasing ionic radius of the metal ion. At elevated reaction temperatures the two new metal phosphonates [Mg2(H2O)5(L)] (5) and [Ba2(H2O)2(L)] ·2 H2O (6) were obtained either from the same reaction mixture as for 1 and 4, respectively, or by solid state transformation. The detailed characterisation of the all materials is also reported. [ABSTRACT FROM AUTHOR]

To improve the removal capacity of NO + O 2 effectively, the alkaline earth metal-doped order mesoporous carbon (A-C-FDU-15(0.001) (A = Mg, Ca, Sr and Ba)) and Mg-C-FDU-15(x) (x = 0.001−0.003) samples were prepared, and their physicochemical and NO + O 2 adsorption properties were determined by means of various techniques. The results show that the sequence in (NO + O 2) adsorption performance was as follows: Mg-C-FDU-15(0.001) (93.2 mg/g) > Ca-C-FDU-15(0.001) (82.2 mg/g) > Sr-C-FDU-15(0.001) (76.1 mg/g) > Ba-C-FDU-15(0.001) (72.9 mg/g) > C-FDU-15 (67.1 mg/g). Among all of the A-C-FDU-15(0.001) samples, Mg-C-FDU-15(0.001) possessed the highest (NO + O 2) adsorption capacity (106.2 mg/g). The species of alkaline earth metals and basic sites were important factors determining the adsorption of NO + O 2 on the A-C-FDU-15(x) samples, and (NO + O 2) adsorption on the samples was mainly chemical adsorption. Combined with the results of (NO + O 2)-temperature-programmed desorption ((NO + O 2)-TPD) and in situ diffused reflectance infrared Fourier transform spectroscopy (DRIFTS) characterization, we deduced that there were two main pathways of (NO + O 2) adsorption: one was first the conversion of NO and O 2 to NO 2 and then part of NO 2 was converted to NO 2 − and NO 3 −; and the other was the direct oxidation of NO to NO 2 − and NO 3 −. [ABSTRACT FROM AUTHOR]

The Al-pillared montmorillonite-supported alkaline earth metal 5M/Al-PILC (PILC = pillared clay, M = Mg, Ca, Sr, and Ba) and x Mg/Al-PILC (x = 1, 3, 5, and 7 wt.%) samples were prepared using an impregnation method. Physical properties of the materials were determined by means of X-ray diffraction (XRD) and N 2 adsorption-desorption, and their CO 2 adsorption behaviors were investigated using the thermogravimetric analyzer (TG), CO 2 temperature-programmed desorption (CO 2 -TPD), and in situ diffuse reflectance infrared transform spectroscopy (in situ-DRIFTS) techniques. It is shown that 5Mg/Al-PILC possessed the highest CO 2 adsorption capacity (2.559 mmol/g). The characterization results indicate that Al-pillaring increased the specific surface area of montmorillonite, which was beneficial for the adsorption of CO 2. The CO 2 adsorption process on the sample was mainly chemical adsorption, and alkalinity was the main factor influencing its adsorption capacity. The alkalinity of the sample was enhanced by loading an appropriate amount of alkaline earth metal, and the adsorbed CO 2 was present in the form of bicarbonate and carbonate. In addition, the 5Mg/Al-PILC sample exhibited an excellent regeneration efficiency. We believe that the outcome of this research would provide a good option for developing highly effective CO 2 adsorption materials. Image, graphical abstract [ABSTRACT FROM AUTHOR]

The stability constant of Efavirenz drug with alkaline earth metal ions Mg(II), Ca(II) and transition metal ions Fe(III), Cu(II) were investigate using pH metric titration technique in 20%(v/v) ethanol-water mixture at 27 °C temperature and at an ionic strength of 0.1M NaClO4.{Metal to ligand ratio = 1:5 & 1:1}The method of Calvin and Bjerrum as adopted by Irving and Rossotti has been employed to determine proton ligand (pKa) and metal-ligand stability constants (log K) values. It is observed that alkaline earth metal & transition metal ion forms 1:1 and 1:2 complexes. The order of stability constants for these metal complexes was as: Fe3+ > Cu2+ > Mg2+ > Ca2+

Zr can be stabilized by the element selected, such as Mg-stabilized Zr (MSZ), thus providing MSZ thin films with potentially wide applications and outstanding properties. This work employed the element from alkaline earth metal stabilized Zr to investigate the electrical properties of sol–gel AZrOx (A = alkaline earth metal; Mg, Sr, Ba) as dielectric layer in metal-insulator–metal resistive random-access memory devices. In addition, the Hume–Rothery rule was used to calculate the different atomic radii of elements. The results show that the hydrolyzed particles, surface roughness, and density of oxygen vacancy decreased with decreased difference in atomic radius between Zr and alkaline earth metal. The MgZrOx (MZO) thin film has fewer particles, smoother surface, and less density of oxygen vacancy than the SrZrOx (SZO) and BaZrOx (BZO) thin films, leading to the lower high resistance state (HRS) current and higher ON/OFF ratio. Thus, a suitable element selection for the sol–gel AZrOx memory devices is helpful for reducing the HRS current and improving the ON/OFF ratio. These results were obtained possibly because Mg has a similar atomic radius as Zr and the MgOx-stabilized ZrOx.

A {CaCo3}-containing sandwich-type polyoxometalate, Li2Na2Ca3(H2O)16{Co3(H2O)[Ca(H2O)5PW8O31](PW9O34)}·16.5H2O (1), was synthesized by using a trivacant phosphotungstate to react with Co2+ and Ca2+ by a conventional aqueous solution method. 1 was characterized by single crystal X-ray diffraction, powder X-ray diffraction, IR spectra, elemental analyses and TG analyses. Structural analysis reveals that 1 is composed of trivacant and a tetravacant phosphotungstates to trap a {Co3} cluster and a Ca2+ cation. The obtained sandwich-type polyoxoanion was further connected to form a two-dimensional expanded structure via the Ca2+ linkers. This work highlights an efficient method to simultaneously introduce both alkaline-earth and transition-metal cations into polyoxotungstates. [ABSTRACT FROM AUTHOR]

Alkaline earth metals (AEMs) act an important role on biomass pyrolysis, which is significant to explore its specific mechanism for further understanding biomass pyrolysis. This study analyzed the influence of Ca and Mg with different anion (CaO, CaCO 3 , CaCl 2 , MgSO 4 , MgCl 2) on biomass pyrolysis, and explored the influence mechanism on the pyrolytic products. Ca and Mg with different anion had obvious different effect on the pyrolytic products from biomass. CaCO 3 had little effect on the distribution of products. And CaO might react with CO 2 and acetic acid to form CaCO 3 , which resulted in that solid yield obviously increased and oil yield decreased. Besides, CaCl 2 and MgCl 2 intensified the ring-open reaction of pyran ring to generate furan. And the formed acidic condition from CaCl 2 and MgCl 2 decomposition might be beneficial to C-C fracture, carboxylation to generate linear aliphatic, CO 2 , and acetic acid, but inhibited the generation of CO. Compared with Ca, Mg had more promotion on the generation of linear aliphatics and cyclopentanones. For biomass, CaCl 2 and MgCl 2 adding might weaken the connection bond between the hemicellulose and cellulose (HC-C) and hemicellulose and lignin (HC-L) in biomass, and resulted in phenyl and CO 2 decreasing but androsugar increasing. However, CaO addition could result in androsurgar decreasing with phenyl increasing. [Display omitted] • The influence mechanism of Ca and Mg with different anion on cellulose and bamboo pyrolysis was explored. • Ca and Mg with different anion have obvious different effect on cellulose and biomass pyrolysis. • CaCl 2 and MaCl 2 intensify the ring opening of pyran structures, C-C fracture, and carboxylation. • CaO react with CO 2 and acetic acid to form CaCO 3. [ABSTRACT FROM AUTHOR]

The present work investigates the near-single green emission properties of Ba2+ doped Ca 9 Y(VO 4) 7 : Yb3+/Er3+ upconversion luminescence. The Ba2+ doped Ca 9 Y(VO 4) 7 : Yb3+/Er3+ phosphors were successfully synthesized via the high-temperature solid-phase method. XRD pattern analysis showed that Ca 9 Y(VO 4) 7 : Yb3+/Er3+/Ba2+ was a single phase, and Ba2+ doping did not induce heterophase phase. Under 980 nm near-infrared laser irradiation, Ca 9 Y(VO 4) 7 : Yb3+/Er3+/Ba2+ phosphors emit strong green luminescence (530 nm, 2H 11/2 →4I 15/2 , 557 nm, 4S 3/2 →4I 15/2) and weak red luminescence (664 nm, 4F 9/2 →4I 15/2). The upconversion green-red luminescence integral intensity ratio of Ca 9 Y(VO 4) 7 : Yb3+/Er3+/Ba2+ phosphor is 32.1. This enhancement can be attributed to the presence of defect bands that facilitate excitation photon absorption and efficient energy transfer from abundant electrons into Yb3+ (2F 5/2) and Er3+ (4I 11/2) ions. More importantly, the maximum S A and S R of Ca 9 Y(VO 4) 7 : Yb3+/Er3+/Ba2+ phosphor as a temperature sensor are 1.44 % K−1 (at 548 K) and 1.28 % K−1 (at 298 K), respectively. [ABSTRACT FROM AUTHOR]

Alkaline earth metals such as magnesium (Mg) and calcium (Ca) are promising catalyst promoters for CO 2 methanation owing to their exceptional basic characteristics. This study details the development of nickel-based catalysts promoted with Mg and Ca supported by exfoliated graphitic carbon nitride (eg-C 3 N 4). The catalysts were synthesised using a facile impregnation technique and characterised using N 2 physisorption, XRD, TEM, XPS, H 2 -TPR and CO 2 -TPD. The Mg-promoted catalyst showed a greater number of mesopores, better dispersion of small Ni NPs, stronger metal-support interaction and enhanced moderate basic sites compared to Ni/eg-C 3 N 4. Conversely, the presence of bulk CaCO 3 species in the Ca-doped catalyst negatively affected the textural properties and basicity. Ni-Mg/eg-C 3 N 4 catalyst demonstrated superior methanation activity with CO 2 conversion (X CO2) of 77% and CH 4 selectivity (S CH4) greater than 99% at 322 °C. This is mainly attributed to the creation of a NiO-MgO solid solution which enhances the interaction between metal and support, leading to the promotion of small and highly dispersed Ni NPs. Moreover, the incorporation of an Mg promoter generates Lewis basic sites and alters the basicity of the eg-C 3 N 4 support, increasing the number of effective CO 2 adsorption sites. The synergy between the Mg dopant and eg-C 3 N 4 support significantly contributes to the high activity and stability for low-temperature CO 2 methanation. [Display omitted] • Mg and Ca-doped Ni/eg-C 3 N 4 catalysts were synthesized by an impregnation method. • Mg-promoted catalyst achieved 77% CO 2 conversion and 99% CH 4 selectivity at 322 °C. • Formation of NiO-MgO solid solution promotes the small, highly dispersed Ni NPs. • MgO species can create Lewis basicity and alters the basicity of eg-C 3 N 4 support. [ABSTRACT FROM AUTHOR]

The poisoning effects of alkali metals (K and Na) and alkaline earth metals (Ca and Mg) on catalytic performance of the 2Nb4Ce/Zr-PILC catalyst for the selective catalytic reduction of NOx with NH3 (NH3-SCR) were investigated, and physicochemical properties of the catalysts were characterized by means of the X-ray diffraction XRD (XRD), Brunner−Emmet−Teller (BET), hydrogen temperature-programmed reduction (H2-TPR), X-ray Photoelectron Spectroscopy (XPS), ammonia temperature-programmed desorption (NH3-TPD), and in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS) techniques. Doping of M (M = K, Na, Ca, and Mg) deactivated the 2Nb4Ce/Zr-PILC catalyst according to the sequence of 0.8 K > 0.8 Na > 0.8 Ca > 0.8 Mg (M/Ce molar ratio = 0.8). The characterization results showed that the decreases in redox ability, NH3 adsorption, Ce3+/Ce4+ atomic ratio, and amount of the chemisorbed oxygen (Oβ) were the important factors influencing catalytic activities of the alkali metal-and alkaline earth metal-doped samples. Consequently, compared with the Mg- and Ca-doped samples, doping of K caused the 2Nb4Ce/Zr-PILC sample to possess the lowest redox ability, NH3 adsorption, and amount of the Oβ species, which resulted in an obvious deactivation effect.

This work evaluated the effects of inherent alkali and alkaline earth metals on nitrogen transformation during steam gasification of Shengli lignite at the temperature of 873–1173 K in a fluidized-bed/fixed-bed quartz reactor. The results indicated that the alkali metal Na and alkaline earth metals Ca, Mg in coal have different effects on inherent nitrogen transformation to NH3, HCN and char-N during the lignite steam gasification. Specifically during the steam gasification of Shengli lignite, Na and Ca, Mg not only catalyze the inherent nitrogen conversions to NH3, but also promote the secondary reactions of the nascent char-N as well as the generation of NH3 from the generated HCN, meanwhile they also inhibited the inherent nitrogen conversion to HCN and char-N. The presence of Na, Ca and Mg hindered the formation of oxidized nitrogen (N-X) functional groups, but enhanced pyridinic nitrogen (N-6) and quaternary nitrogen's (N-Q) formation in char. [ABSTRACT FROM AUTHOR]

Abstract Two new s -block metal-containing coordination polymers, viz. [M(ona)] n (M = Ba (1), Ca (2); ona = 2‑hydroxylnicotinic anion), have been synthesized under hydrothermal condition. Single crystal X-ray diffraction analysis discloses that both 1 and 2 display two-dimensional wave-like layer construction. The involved in situ substitution reaction was studied in detail and it was found that the compounds can be generated by reacting MO (M = Ba, Ca) with either 2‑mercaptonicotinic acid (H 2 mna) or 2‑hydroxylnicotinic acid (H 2 ona). 1 and 2 were further characterized by CHN elemental analysis, Fourier transform infrared spectroscopy and powder X-ray diffraction. Besides, the obtained s -block metal-containing coordination polymers exhibited good thermal stability as revealed by thermogravimetric analysis. Moreover, their solid-state photoluminescent properties were also investigated at room temperature. Graphical abstract Unlabelled Image Highlights • Two new s -block metal-containing coordination polymers were synthesized. • The involved in situ substitution reaction of sulfur by oxygen was studied in detail. • The obtained coordination polymers exhibited good thermal stability. • The solid-state photoluminescent properties were investigated at room temperature. [ABSTRACT FROM AUTHOR]

Abstract In this research, the effect of alkaline earth promoters (Mg, Sr, Ca and Ba) on the catalytic performance of the 7 wt%Ni-7.5 wt%Cu/CeO 2 Al 2 O 3 catalyst in high-temperature water gas shift (HTWS) reaction was studied. The mesoporous support was prepared via a simple solid-state method with the BET surface area of 94.46 m2 g−1. The results indicated that among the prepared catalysts, the Ba-promoted catalyst demonstrated a high CO conversion (68.9% at 450 °C) and a low decline in BET area after the reaction. The maximum methane production for this catalyst was lower than that observed for the unpromoted catalyst that could be related to the higher concentration of basic sites in the Ba-promoted catalyst. Although, a higher amount of Ba can improve the selectivity toward water gas shift reaction, increasing the Ba content from 4 wt% to 6 wt% had a negative effect on the activity. Moreover, the addition of Ba to 7Ni-7.5Cu/CeO 2 Al 2 O 3 improved the long-time stability of the catalyst. Graphical abstract Image 1 Highlights • The simple solid-state method was used for the preparation of CeO 2 Al 2 O 3 support. • The role of Mg, Ba, Ca and Sr promoters was studied on the activity of Ni Cu catalyst. • All promoters increased the activity and decreased the CH 4 production. • Ba-promoted Ni Cu/CeO 2 Al 2 O 3 catalyst had higher activity than the other catalysts. • Ba-promoted catalyst presented better long-time stability than an unpromoted catalyst. [ABSTRACT FROM AUTHOR]

The steric bulk of the well‐known DIPPBDI ligand (CH[C(CH3)N‐DIPP]2, DIPP=2,6‐diisopropylphenyl) was increased by replacing isopropyl for isopentyl groups. This very bulky DIPePBDI ligand could not stabilize the radical species (DIPePBDI)Mg.: reduction of (DIPePBDI)MgI with Na gave (DIPePBDI)2Mg2 with a rather long Mg‐Mg bond of 3.0513(8) Å. Addition of TMEDA prior to reduction gave complex (DIPePBDI)2Mg2(C6H6), which could also be obtained as its THF adduct. It is speculated that combination of a bulky spectator ligand and TMEDA prevents dimerization of the intermediate MgI radical, which then reacts with the benzene solvent. Complex (DIPePBDI)2Mg2(C6H6), which formally contains the anti‐aromatic anion C6H62−, reacted with tBuOH as a Brønsted base to 1,3‐ and 1,4‐cyclohexadiene and with H2 as a two electron donor to (DIPePBDI)2Mg2H2 and C6H6. It also reductively cleaved the C−F bond in fluorobenzene and gave (DIPePBDI)MgPh, (DIPePBDI)MgF, and C6H6. Pepping up chemistry with DIPeP: Replacing the isopropyl groups in a commonly used β‐diketiminate ligand for isopentyl substituents gives the super bulky DIPePBDI ligand. Its dinuclear MgI complex, (DIPePBDI)2Mg2, features a strongly elongated Mg−Mg bond. Attempted isolation of the radical (DIPePBDI)Mg. gave (DIPePBDI)2Mg2(C6H6) in which the formally reduced benzene, C6H62−, is a very strong reductant. [ABSTRACT FROM AUTHOR]

Highlights • Aluminosilicate glasses contained with alkaline earth elements were attempted as new plasma resistant materials. • Calcium alumino-silicate glass showed the lowest etch rate, which corresponds to 72% of that recorded by sapphire. • The plasma resistant properties of RAS glass are more influenced by the sublimation temperature with fluoride than atomic binding energy. Abstract High-density plasma dry etching was performed with a mixture of CF 4 /O 2 /Ar gases, and the plasma resistant properties of RO-Al 2 O 3 -SiO 2 (R: alkaline earth) glass were analyzed. RAS had etch rates below 25㎚/min, which are lower than that of alumina and sapphire. CAS showed an improvement in the etch rate, which corresponds to 72% of that recorded by sapphire. The plasma resistant properties of RAS glass are more significantly influenced by the sublimation temperature with fluoride than atomic binding energy. The difference in the etch rates of the RAS glass was smaller at higher sublimation temperatures. [ABSTRACT FROM AUTHOR]

Abstract The goal of this work is to determine an impact of the modification method of Ni/ZrO 2 catalyst by alkali and alkaline earth metals on its activity in thermo-chemical conversion of cellulose to hydrogen-rich gas. Me x O-ZrO 2 supports (where Me = Ca, Mg, Na or K) were prepared by impregnation, precipitation and sol-gel methods. The obtained results reveal that an introduction of dopants to the zirconia support considerably enhances the H 2 yield in comparison to unmodified catalyst. An increase in the hydrogen formation is accompanied by a rise in the total volume of the produced gases. It is demonstrated that the highest amount of hydrogen is formed in the presence of the catalysts containing CaO-ZrO 2 support followed by Na doped materials. This phenomenon can be attributed to more efficient incorporation of Ca2+ and Na+ cations in the zirconia lattice making it more stable in the reaction conditions. Moreover, it is observed that an activity order of the investigated catalysts is consistent with the changes in the basic character of their surface. Highlights • Presence of alkali metals increases production of hydrogen-rich gas from cellulose. • Ni/CaO-ZrO2 catalyst most active in hydrogen production from cellulose. • Sol-gel method allows for synthesis of most effective support of Ni. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mechanochemical hydrogenation of shell wastes was studied at room temperature. • Alkaline metals can selectively assist the hydrogenation of shell wastes to CH 4. • The calcium metal has a better effect and the methane yield can reach 45.04%. • By doping Ru the methane yield of shell wastes can be improved to 54.76%. • This study provides a method to eliminate shell wastes and produce CH 4 fuel. Producing clean fuel using shell wastes (eggshell and clamshell) can eliminate food waste and alleviate the energy shortage. Mechanochemical hydrogenation of eggshell/clamshell was investigated at room temperature. The results show that the alkaline earth metals can effectively assist the hydrogenation of shell wastes to CH 4. The calcium metal has a better effect, and the methane yield for the calcium-assisted hydrogenation of clamshell and eggshell reaches 45.04% and 33.30% with 100% CH 4 selectivity. At the same time, the calcium-assisted methanation of shell wastes in the presence of transition metals (Fe, Co, Ni, Ru) was investigated. By doping Ru, the methane yield of clamshell and eggshell was improved to 52.62% and 54.76%, respectively. The milling time, rotating speed, hydrogen pressure, and the species of the doped transition metals influence the calcium-assisted methanation of shell wastes. This study provides an alternative method to eliminate shell wastes and produce clean CH 4 fuel at room temperature. [ABSTRACT FROM AUTHOR]

This work reports the synthesis and photovoltaic properties of a new semiconductor–ternary alloyed Ba x Cd 1 −x S nanocrystals, prepared by replacing a fraction of the Cd2+ ions in the host CdS with Ba2+ ions (x = 0−0.13) using the sequential ionic layer adsorption and reaction. Optical measurements revealed a decreasing bandgap in Ba x Cd 1 −x S from 2.24 to 2.14 eV with increasing x , increasing the optical absorption range from 300 to 553 nm in CdS to 300−579 nm in Ba x Cd 1 −x S. Liquid-junction semiconductor quantum dot-sensitized solar cells (QDSSCs) were fabricated from Ba x Cd 1 −x S nanocrystals using polysulfide electrolyte and CuS counter electrode. The Ba 0. 09 Cd 0. 91 S QDSSC (x = 0.09) yielded the best power conversion efficiency (PCE) of 3.95% under 1 sun, which is 33% higher than that (2.96%) of the host CdS. A ZnS passivation layer treatment on the best Ba 0.09 Cd 0.91 S sample increased the PCE to 4.57% (J SC = 9.33 mA/cm2, V oc = 0.80 V, fill factor = 61.2%) under one sun. The PCE further increased to 5.21% under a reduced light intensity of 0.1 sun. This work demonstrates the potential of tunable optoelectronic properties in Ba x Cd 1 −x S by controlling the Ba content and enhancing the photovoltaic performance by increasing the absorption range. [Display omitted] • The first demonstration of alkaline earth metal-doped Ba x Cd 1-x S quantum dot-sensitized solar cells. • The band gap decreases from 2.24 eV in CdS to 2.14 eV in Ba x Cd 1-x S. • The light absorption band increases from 300 to 553 nm in CdS to 300−579 nm in Ba x Cd 1−x S. • The PCE of Ba x Cd 1-x S QDSSCs is 33% higher than that of the host CdS cell. • The best PCE of Ba x Cd 1-x S QDSSCs equals 5.21% at 0.1 sun. [ABSTRACT FROM AUTHOR]