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The aim of this investigation was to explore the possibility to perform an asymmetric reduction, utilising a CBS‐type catalyst, of prochiral aryl methyl ketones under electrochemical conditions to generate the needed BH3 upon oxidation of NaBH4 with in situ generated I2 in the anode compartment. Therefore, various electrochemical parameters were optimised to conduct the desired formation of the chiral secondary alcohols in high to quantitative yields with a high stereochemical induction, although the catalyst loading had to be chosen relatively high to concur with the racemic reduction of the ketones by the electrogenerated BH3. [ABSTRACT FROM AUTHOR]

NaAlCl4 solid electrolyte is a highly promising solid-state sodium-ion electrolyte with significant application potential. However, most studies on the modification of such material have focused on the impact of cation doping on performance, and the effects of anion doping remain unknown. In this work, fluoride (F−) and borohydride (BH4−) were successfully introduced into NaAlCl4 using a mechanical ball milling method, resulting in the synthesis of NaAlCl4−xFx (x = 0, 0.1, 0.3, 0.5, and 0.7) and NaAlCl4−x(BH4)x (x = 0.1 and 0.3). These derivatives maintain the same orthorhombic structure as NaAlCl4. Electrochemical measurements validate the feasibility of F− and BH4− doping for modifying the NaAlCl4 electrolyte. X-ray photoelectron spectroscopy (XPS) analyses demonstrate that the fluorinated Na/NaAlCl3.5F0.5 interphase formed during cyclic voltammetry (CV) measurements, this prevented further side reactions. This work reveals that F− and BH4− doping exhibit similar electrochemical effects, holds profound practical significance for future research in modifying halide-based sodium ion solid electrolytes. [ABSTRACT FROM AUTHOR]

In this study, we investigated the deliquescence of NaBH 4 thin films under atmospheric conditions toward their hydrogen supply application. Upon exposed to air, the film deliquesced along with generating hydrogen due to the decomposition of [BH 4 ]- ions, but the decomposition rate was slow enough for a sizable amount of [BH 4 ]- ions remained stable in the deliquesced film. As a result, a reversible deliquescence-recrystallization cycle in the NaBH 4 thin film could be achieved through control of humidity. Molecular dynamics simulations suggested that Na+ and [BH 4 ]- ions tended to neighbor each other with almost the same intra-distance as that in the crystal. A kind of such local ordered structures in deliquesced NaBH 4 may prevent an excess hydration and subsequent decomposition of [BH 4 ]- ions and is responsible for the stability of [BH 4 ]- ions, enabling the reversible deliquescence-recrystallization cycle. These combined experimental and theoretical insights offer new perspectives on controlling hydrogen release from borohydrides based on humidity conditions in the thin film form. • Deliquescence of NaBH 4 thin films on Si (100) substrates explored. • Raman spectra confirm prevalence of [BH 4 ]- ions in deliquesced state. • In-situ XRD reveals reversible recrystallization and deliquescence cycle. • MD simulations suggest local molecular-like structure prevents excess hydration. • Insights gained into controlled hydrogen release, offering novel borohydride applications. [ABSTRACT FROM AUTHOR]

In this research work, surface-modified nano zerovalent copper (nZVC) was prepared using a simple borohydride reduction method. The spectroscopic and crystallographic results revealed the successful synthesis of surface-modified nano zerovalent copper (nZVC) using solvents such as ethanol (ETOH), ethylene glycol (EG) and tween80 (T80). The as-synthesized material was fully characterized for morphological surface and crystal structural properties. The results indicated that EG provides an excellent synthesis environment to nZVC compared to ETOH and T80 in terms of good dispersion, high surface area and excellent catalytic properties. The catalytic efficiency of nZVC/EG was investigated alone and with peroxymonosulphate (PMS) in the absence of light. The degradation results demonstrated that the involvement of PMS synergistically boosted the catalytic efficiency of synthesized nZVC/EG material. Furthermore, the degradation products (DPs) of CBZ were determined by GC−MS and subsequently, the degradation pathways were proposed. The ecotoxicity analysis of the DPs was also explored. The proposed (nZVC/EG/PMS) system is economical and efficient and thus could be applied for the degradation of CBZ from an aquatic system after altering the degradation pathways in such a way that results in harmless products. [ABSTRACT FROM AUTHOR]

DNA–protein crosslinks (DPC) are common DNA lesions induced by various external and endogenous agents. One of the sources of DPC is the apurinic/apyrimidinic site (AP site) and proteins interacting with it. Some proteins possessing AP lyase activity form covalent complexes with AP site‐containing DNA without borohydride reduction (suicidal crosslinks). We have shown earlier that tyrosyl‐DNA phosphodiesterase 1 (TDP1) but not AP endonuclease 1 (APE1) is able to remove intact OGG1 from protein–DNA adducts, whereas APE1 is able to prevent the formation of DPC by hydrolyzing the AP site. Here we demonstrate that TDP1 can remove intact PARP2 but not XRCC1 from covalent enzyme–DNA adducts with AP‐DNA formed in the absence of APE1. We also analyzed an impact of APE1 and TDP1 on the efficiency of DPC formation in APE1−/− or TDP1−/− cell extracts. Our data revealed that APE1 depletion leads to increased levels of PARP1–DNA crosslinks, whereas TDP1 deficiency has little effect on DPC formation. [ABSTRACT FROM AUTHOR]

A sensitive and interference-free method based on hydride generation high-resolution continuum source quartz tube atomic absorption spectrometry in dilute HCl was developed for total and inorganic As (tAs, iAs) determination in soil, sediments, and sludge. Sample preparation involved microwave-assisted digestion in aqua regia for tAs and extraction in 10 mol L−1 HCl for iAs. In both cases, the prereduction of As(V) to As(III) was carried out with L-cysteine, while derivatization to arsine with 0.6% NaBH4 was performed in the presence of 0.2% L-cysteine in 0.01 mol L−1 HCl (pH 2.00 ± 0.01). Inorganic arsenic determination was validated with 87 ± 7% extraction efficiency. The recovery of tAs in certified reference materials was 98 ± 23%, while the value for iAs in spiked samples was 95 ± 10%. The method was selective for iAs determination and did not require separation of iAs by liquid-liquid extraction in an organic solvent. The results were verified using the Tukeyʼs multiple comparison test for p > 0.05 (experimental values 0.063 to 0.999). The method is greatly simplified due to no requirement for the separation of iAs species, absence of spectral interference, similar derivatization conditions for tAs/iAs, and possibility of using external calibration. The limits of detection for tAs and iAs were 0.006 mg kg−1. Concentrations of 0.37–545 mg kg−1 tAs and 0.33–280 mg kg−1 iAs in real samples were determined with precisions from 3.7 to 12.2% and 6.8 to 15.0%. [ABSTRACT FROM AUTHOR]

Selective laser melting can be used to create custom‐made monolith reactor components with embedded microscale catalytic sites. Doping with noble metals (0.01–0.04 % of Pt, Ir, Ru, or Rh) gave clean incorporation of the active metal particles metals. Yet catalytic activity was low, due to distribution of the active particles between the surface and the bulk of the monolith. Switching to cobalt enabled doping in higher amounts (1.5–2.0 %) with corresponding increase in activity. Using borohydride hydrolysis as a test reaction, we showed that a combined stainless steel and cobalt monolith was active in both batch and continuous systems, for at least 48 h, albeit with some loss of active material. The advantages and limitations of this catalyst/reactor preparation method are discussed. [ABSTRACT FROM AUTHOR]

The reduction mechanism of aldehyde/ketones with M(BH4)n is not fully understood, even though the hydroboration mechanism of weak Lewis base borane complexes is known to involve a four-membered ring transition state. Herein, the reduction mechanism of M(BH4)n in aprotic solvents has been elucidated for a six-membered ring, in which hydride transfer to the C atom from the B atom, formation of an L·BH3 adduct, and disproportionation of (BH3(OR)−) borane are involved. The metal cations and solvents participate in and significantly influence the reaction procedure. We believe that this mechanistic study would provide a further reference for the application of M(BH4)n in organic reactions. [ABSTRACT FROM AUTHOR]

Dielectric barrier discharge (DBD) plasma is used to prepare ternary heterostructured Ru–Co–B oxide catalyst with considerable RuO 2 /CoO/B 20 H 26 O interface and oxygen vacancy (Ov) for enhanced borohydride oxidation reaction. the Ru–Co–B catalyst displayed remarkable electrocatalytic activity and long-term stability Due to the difference in energy band structure at the interface where the charge distribution is not homogeneous, the heterogeneous structure will spontaneously generate a built-in electric field which prompts the interfacial charge transfer. The production of Ov increases its active site and promotes its catalytic activity. While it is used in membrane-less direct borohydride fuel cells (DBFCs), it showed a peak power density of 206 mW cm−2 at room temperature and a remarkable stability of 270 h at a constant current of 20 mA that is superior to commercial Pt/C. [Display omitted] • Heterogeneous catalysts with abundant oxygen vacancies were synthesized by plasma technology. • The use of ruthenium instead of platinum reduces the cost of the fuel cells. • The power density can reach 206 mW cm−2, the stability is greatly improved. • The preparation process does not need high temperature treatment, achieving green color, low energy consumption. [ABSTRACT FROM AUTHOR]

A comprehensive correlation between the weakening of sp3 hybridization in the de-hydrogenation and the sp2 hybridization in the hydrogenation processes have been established, enabling the identification and screening of optimal candidates capable of achieving reversible de-hydrogenation and re-hydrogenation in borohydrides. [Display omitted] Borohydrides offer promise as potential carriers for hydrogen storage due to their high hydrogen concentration. However, the strong chemical bonding within borohydrides poses challenges for efficient hydrogen release during usage and restricts the re-hydrogenation process when attempting to regenerate the material. These high thermodynamic and kinetic barriers present obstacles in achieving reversible de-hydrogenation and re-hydrogenation of borohydrides, impeding their practical application in hydrogen storage systems. Employing density functional theory calculations, we conduct a comprehensive investigation into the influence of transition metals on both the BH 4 cluster, a fundamental building block of borohydrides, and pure boron, which is formed as the end product following hydrogen release. Our research reveals correlations among the d -band center, work function, and surface energy of 3d and 4d transition metals. These correlations are directly linked to the weakening of bonding within the BH 4 cluster when adsorbed on catalyst surfaces. On the other hand, we also explore how various intrinsic properties of transition metals influence the formation of boron vacancies and the hydrogen bonding process. By establishing a comprehensive correlation between the weakening of sp3 hybridization in the BH 4 cluster and the sp2 hybridization in boron, we facilitate the identification and screening of optimal candidates capable of achieving reversible de-hydrogenation and re-hydrogenation in borohydrides. [ABSTRACT FROM AUTHOR]

Direct borohydride fuel cells (DBFCs) convert borohydride (NaBH4) chemical energy into clean electricity. However, catalytic active site deactivation in NaBH4 solution limits their performance and stability. We propose a strategy to regulate active sites in Co‐based catalysts using polypyrrole modification (Co−PX catalyst) to enhance electrochemical borohydride oxidation reaction (eBOR). As an anode catalyst, the synthesized Co−PX catalyst exhibits excellent eBOR performance in DBFCs, with current density of 280 mA ⋅ cm−2 and power density of 151 mW ⋅ cm−2, nearly twice that of the unmodified catalyst. The Co‐PX catalyst shows no degradation after 120‐hour operation, unlike the rapidly degrading control. In‐situ electrochemical attenuated total reflection Fourier‐transform infrared spectroscopy (ATR‐FTIRS) and density functional theory (DFT) suggest that polypyrrole‐modified carbon support regulate the charge distribution, increasing oxidation state and optimizing adsorption/desorption of intermediates. A possible reaction pathway is proposed. This work presents a promising strategy for efficient polymer‐modulated catalysts in advanced DBFCs. [ABSTRACT FROM AUTHOR]

Borohydride imidazolium ionic liquids, [IL]BH4, used for the first time as reductants in the N‐formylation of various amines with CO2, provided an excellent yield of formamides. Under the same conditions, 5 bar CO2 and 80 °C, NaBH4 produced a mixture of N‐formylated and N‐methylated products in a ratio of 1 : 2. An alternative approach, based on the addition of halide imidazolium salts ([IL]Cl or [IL]Br) to the reactions of amine with NaBH4 and CO2, resulted in a significant increase of selectivity to formamide. However, no effect was noted for [IL]BF4 and [IL]PF6. Monitoring the reaction course in time using 1H NMR brought about new insight into the role of BH3 in the reduction of CO2 and the functionalization of amines. The formation of N‐methylaniline – borane intermediate was evidenced. [ABSTRACT FROM AUTHOR]

The magnesium borohydride complexes with ammonia, Mg(BH4)2•2NH3 (MA-2) and Mg(BH4)2•3NH3 (MA-3), were obtained in a single crystal form and their structures were determined by the X-ray diffraction analysis. According to the powder X-ray diffraction and IR spectroscopy results, the data in some published works, where the MA-3 was positioned as an individual compound, were shown to contain additional reflections that are in good agreement with those for Mg(BH4)2•6NH3 (MA-6). The study of the thermolysis process of the individual MA-3 by DSC-TGA-MS showed that the heating of the triammine to a temperature of 600 °C leads to the release of ammonia and hydrogen in a molar ratio H2: NH3 = 8: 1, with a total yield of H2 reaching 12 wt.%. [ABSTRACT FROM AUTHOR]

Abstract The aim of this investigation was to explore the possibility to perform an asymmetric reduction, utilising a CBS‐type catalyst, of prochiral aryl methyl ketones under electrochemical conditions to generate the needed BH3 upon oxidation of NaBH4 with in situ generated I2 in the anode compartment. Therefore, various electrochemical parameters were optimised to conduct the desired formation of the chiral secondary alcohols in high to quantitative yields with a high stereochemical induction, although the catalyst loading had to be chosen relatively high to concur with the racemic reduction of the ketones by the electrogenerated BH3.

All-solid-state batteries have recently gained considerable attention due to their potential improvements in safety, energy density, and cycle-life compared to conventional liquid electrolyte batteries. Sodium all-solid-state batteries also offer the potential to eliminate costly materials containing lithium, nickel, and cobalt, making them ideal for emerging grid energy storage applications. However, significant work is required to understand the persisting limitations and long-term cyclability of Na all-solid-state-based batteries. In this work, we demonstrate the importance of careful solid electrolyte selection for use against an alloy anode in Na all-solid-state batteries. Three emerging solid electrolyte material classes were chosen for this study: the chloride Na2.25Y0.25Zr0.75Cl6, sulfide Na3PS4, and borohydride Na2(B10H10)0.5(B12H12)0.5. Focused ion beam scanning electron microscopy (FIB-SEM) imaging, X-ray photoelectron spectroscopy (XPS), and electrochemical impedance spectroscopy (EIS) were utilized to characterize the evolution of the anode-electrolyte interface upon electrochemical cycling. The obtained results revealed that the interface stability is determined by both the intrinsic electrochemical stability of the solid electrolyte and the passivating properties of the formed interfacial products. With appropriate material selection for stability at the respective anode and cathode interfaces, stable cycling performance can be achieved for Na all-solid-state batteries.

Herein, a hetero-structured catalyst CoP-Co supported on porous g-C 3 N 4 nanosheets (CoP-Co/CN-I) was prepared by pyrolysis and P-inducing strategy. The optimal catalyst achieves a turnover frequency (TOF) of 26 min−1 at room temperature and the apparent activation energy (E a) is 35.5 kJ·mol−1. The catalytic activity is ranked top among the non-precious metal phosphides or the other supports. Meanwhile, the catalytic activity has no significant decrease even after 5 cycles. The CoP/Co interfaces provide richly exposed active sites, optimize hydrogen/water absorption free energy via electronic coupling, and thus improve the catalytic activity. The experimental results reveal that the CoP/Co heterojunction improves the catalytic activity due to the construction of dual-active sites. This research facilitates the innovative construction of non-noble metal catalysts to meet industrial demand for heterogeneous catalysis. [Display omitted] • A CoP/Co heterojunction on porous g-C 3 N 4 nanosheets as a highly efficient catalyst is designed deliberately through pyrolysis and phosphorus-inducing (P-inducing) strategy. • The construction of Co-P and Co dual-active site in this research resulting in the ability to simultaneously active NH 3 BH 3 and H 2 O molecule on CoP-Co/CN-I and enhanced their intrinsic activity via tuning the surface electronic property. • An outstanding TOF of 26 min−1 was obtained over Co-P and Co dual-active sites on CoP-Co/CN-I compared with separate Co-P site or Co site during NH 3 BH 3 hydrolysis (Co activate H 2 O and Co-P activate NH 3 BH 3). Designing non-precious catalysts to synergistically achieve a facilitated exposure of abundant active sites is highly desired but remains a significant challenge. Herein, a hetero-structured catalyst CoP-Co supported on porous g-C 3 N 4 nanosheets (CoP-Co/CN-I) was prepared by pyrolysis and P-inducing strategy. The optimal catalyst achieves a turnover frequency (TOF) of 26 min−1 at room temperature and the apparent activation energy (E a) is 35.5 kJ·mol−1. The catalytic activity is ranked top among the non-precious metal phosphides or the other supports. Meanwhile, the catalytic activity has no significant decrease even after 5 cycles. The CoP/Co interfaces provide richly exposed active sites, optimize hydrogen/water absorption free energy via electronic coupling, and thus improve the catalytic activity. The experimental results reveal that the CoP/Co heterojunction improves the catalytic activity due to the construction of dual-active sites. This research facilitates the innovative construction of non-noble metal catalysts to meet industrial demand for heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

The derivatization of dialdehyde cellulose (DAC) has received increasing attention in the development of sustainable thermoplastics. In this study, a series of dialcohol celluloses were generated by borohydride reduction, which exhibited glass transition temperature (Tg) values ranging from 23 to 109 °C, depending on the initial degree of oxidation (DO) of the DAC intermediate. However, the DAC derivatives did not exhibit thermoplastic behavior when the DO of the modified DAC was below 26 %. The influence of introduced side chains was highlighted by comparing DAC‐based thermoplastic materials obtained by either oximation or borohydride reduction. Our results provide insights into the generation of DAC‐based thermoplastics and highlight a strategy for tailoring the Tg by adjusting the DO during the periodate oxidation step and selecting appropriate substituents in subsequent modifications. [ABSTRACT FROM AUTHOR]

A NiB binary catalyst with a unique mulberry-like nanoparticle morphology has been prepared by one-step electrodeposition. The NiB-0.2 catalyst exhibits excellent catalytic activity, selectivity, and stability for the borohydride oxidation reaction. Moreover, a direct borohydride fuel cell using the NiB-0.2 catalyst anode can deliver a peak power density of 453 mW cm−2 and open-circuit voltage of 1.96 V at 343 K. The improved performances are due to the introduction of B. This study may inspire the development of efficient noble-metal-free anode catalysts for DBFCs. [ABSTRACT FROM AUTHOR]

The use of natural materials derived from biomass or biodegradable polymer materials can be one of the solutions to be considered in reducing environmental pollution problems. In addition, some polymers have been shown to be biocompatible and thus beneficial in biomedical applications. Therefore, within the framework of this study, we will present the results of the application of lanthanide-borohydride systems (Nd(BH4)3(THF)3) combined with n-butylethyl magnesium in the block copolymerization of conjugated dienes (myrcene-styrene) and a conjugated diene with a polar monomer (L-lactide) for the synthesis of bio-sourced elastomers. The analysis of copolymers resulting from the copolymerization between myrcene and styrene shows that it is possible to insert up to 9.9% of styrene. Moreover, the stereoselectivity (1,4-trans) of the myrcene motif has not significantly changed, even in the presence of a significant amount of styrene in the reaction medium. The presence of the copolymer was confirmed by the observation of a peak at 146 ppm which corresponds to the ipso carbon of styrene. [ABSTRACT FROM AUTHOR]

The method to synthesize high‐capacity complex hydride nanostructures, such as borohydrides, decorated with metallic shells has surfaced as an attractive approach for enabling reversible hydrogen storage. However, the current solvent‐based synthesis methods of such core‐shell nanostructures are limited by solvents/hydrides compatibility issues and the low solubility of the shell precursor in such solvents. Herein, for the first time, an alternative solid‐state method to prepare core‐shell‐like nanostructures is reported. Simply, by mixing and heating vanadium (V)‐doped sodium borohydride (V‐NaBH4) cores and nickelocene (as nickel precursor) at 150 °C, it is possible to decorate V‐NaBH4 with Ni, which shows an improved hydrogen release (≈8 mass% H2) at 350 °C and a net reversible hydrogen capacity of 2 mass%. Detailed structural investigations reveal that the in‐situ formed VxBy and NixBy are responsible for superior hydrogen absorption in the core‐shell material, where these boride species around the shell/interfaces suppress the loss of Na or B and the formation of B12H12 during hydrogen release/uptake. This work opens solvent‐free pathways to design and control the chemical composition of core–shell (boro)hydrides for practical hydrogen storage. [ABSTRACT FROM AUTHOR]

The selection and design of new electrode materials for energy conversion and storage are critical for improved performance, cost reduction, and mass manufacturing. A bifunctional anode with high catalytic activity and extended cycle stability is crucial for rechargeable lithium‐ion batteries and direct borohydride fuel cells. Herein, a high entropy novel three‐dimensional structured electrode with Pr‐doped hollow NiFeP nanoflowers inlaid on N‐rGO was prepared via a simple hydrothermal and self‐assembly process. For optimization of Pr content, three (0.1, 0.5, and 0.8) different doping ratios were investigated. A lithium‐ion battery assembled with NiPr0.5FeP/N‐rGO electrode achieved an outstanding specific capacity of 1.61 Ah g−1 at 0.2 A g−1 after 100 cycles with 99.3 % Coulombic efficiencies. A prolonged cycling stability of 1.02 Ah g−1 was maintained even after 1000 cycles at 0.5 A g−1. In addition, a full cell battery with NiPr0.5FeP/N‐rGO∥LCO (Lithium cobalt oxide) delivered a promising cycling performance of 0.52 Ah g−1 after 200 cycles at 0.15 A g−1. Subsequently, the NiPr0.5FeP/N‐rGO electrode in a direct borohydride fuel cell showed the highest peak power density of 93.70 mW cm−2 at 60 °C. Therefore, this work can be extended to develop advanced electrode for next‐generation energy storage and conversion systems. [ABSTRACT FROM AUTHOR]

The rapid development of industry has accelerated the utilization and consumption of fossil energy, resulting in an increasing shortage of energy resources and environmental pollution. Therefore, it is crucial to explore new energy storage devices using renewable and environment-friendly energy as fuel. Direct borohydride fuel cells (DBFCs) are expected to be a feasible and efficient energy storage device by virtue of the read availability of raw materials, non-toxicity of products, and excellent operational stability. Moreover, while utilizing H2O2 as an oxidant, a significant theoretical energy density of 17 kW h kg−1 can be achieved, indicating the broad application prospect of DBFCs in long-range operation and oxygen-free environment. This review summarizes the research progress on DBFCs in term of reaction kinetics, electrode materials, membrane materials, architecture, and electrolytes. In addition, we predict the future research challenges and feasible research directions, considering both performance and cost. We hope this review will help guide future studies on DBFCs. [ABSTRACT FROM AUTHOR]

Herein, the efficiency of the Co catalyst synthesized in caffeine-based carbon quantum dot-supported material using ethanol solvent was evaluated for H 2 production from the hydrolysis of KBH 4. The chemical compositions and morphology structures of these caffeine carbon dot-supported Co catalysts were carefully characterized by XRD, TEM, BET, EDS, FTIR, XPS, and ICP/OES analyses. XPS, FTIR and EDX analyses showed abundant oxygen atoms on the caffeine carbon dot-supported Co catalyst. It can be attributed to the prevention of aggregation of particles by reducing the average particle size with both caffeine and carbon quantum dots materials. The catalysts prepared in methanol and ethanol solvent by hydrothermal treatment compared to water have significant effects on H 2 production from KBH 4 hydrolysis. The H 2 production rate obtained by Co@MOF-CQD (ethanol) at 30 °C was 17,081 ml min−1g−1. At the same time, the TOF value obtained with 4% KBH 4 for the Co@MOF-CQD (ethanol) was found as 2765 h−1. The reusability of Co@CQD-MOF(ethanol) for the catalytic hydrolysis of KBH 4 for H 2 production was evaluated by six consecutive experiments. [Display omitted] • Accessibility of the active catalyst surface is important for H 2 production rate. • Catalyst particle diameter is vital for H 2 production from KBH 4 hydrolysis. • Catalysts prepared in different solvents are also effective on H 2 production from KBH 4. • Caffeine carbon quantum dot supported Co catalyst was synthesized in ethanol. • H 2 production rate obtained by Co@MOF-CQD (ethanol) was 17,081 ml min−1g−1. [ABSTRACT FROM AUTHOR]

Direct borohydride fuel cells (DBFC) have a promising future as a new type of fuel cell with a high energy conversion rate and a green profile, the performance of which is mainly determined by the anode catalyst. Precious metals as anode catalysts have better catalytic ability but are expensive, limiting their application. Hydrogen storage alloys as anode catalysts can inhibit hydrolysis and enhance the conversion efficiency, but have poor catalytic ability. On this basis, Ag modified La–Mg–Ni hydrogen storage alloy catalyst (La–Mg–Ni@Ag) was synthesized by photo-deposition method in this study. The microstructures and surface morphologies of Ag, La–Mg–Ni alloy and La–Mg–Ni@Ag composite alloy were investigated in detail by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Their catalytic and electrochemical properties towards BH 4 − were evaluated by cyclic voltammetry (CV) and chronoamperometry (CA). The results show that the La–Mg–Ni@Ag composite catalyst is composed of Ag and La–Mg–Ni alloy phase structure, and La–Mg–Ni alloy particles are closely covered by tiny particles of Ag. In addition, the La–Mg–Ni@Ag composite catalyst has better catalytic activity and stability than those of La–Mg–Ni hydrogen storage alloy catalyst, with an increase in peak oxidation current density of about 50% and an increase in the number of transferred electrons of about 3. • La–Mg–Ni@Ag composite catalyst is successfully synthesized by photo-deposition method. • La–Mg–Ni@Ag catalyst forms a core-shell structure with La–Mg–Ni as the core and fine particles of Ag as the shell. • The catalytic performance of the La–Mg–Ni@Ag catalyst is much better than that of the La–Mg–Ni catalyst. [ABSTRACT FROM AUTHOR]

Searching for novel solid electrolytes is of great importance and challenge for all‐solid‐state Mg batteries. In this work, we develop an amorphous Mg borohydride ammoniate, Mg(BH4)2·2NH3, as a solid Mg electrolyte that prepared by a NH3 redistribution between 3D framework‐γ‐Mg(BH4)2 and Mg(BH4)2·6NH3. Amorphous Mg(BH4)2·2NH3 exhibits a high Mg‐ion conductivity of 5 × 10−4 S cm−1 at 75 °C, which is attributed to the fast migration of abundant Mg vacancies according to the theoretical calculations. Moreover, amorphous Mg(BH4)2·2NH3 shows an apparent electrochemical stability window of 0–1.4 V with the help of in‐situ formed interphases, which can prevent further side reactions without hindering the Mg‐ion transfer. Based on the above superiorities, amorphous Mg(BH4)2·2NH3 enables the stable cycling of all‐solid‐state Mg cells, as the critical current density reaches 3.2 mA cm−2 for Mg symmetrical cells and the reversible specific capacity reaches 141 mAh g−1 with a coulombic efficiency of 91.7% (first cycle) for Mg||TiS2 cells. [ABSTRACT FROM AUTHOR]

Borane is a class of boron compounds, including active small borane molecules and relative stable polyhedral borane compounds, and has widely applied in energy storage, material science, and pharmaceutical medicine, especially as promising boron carriers for boron neutron capture therapy(BNCT), and many other fields. The synthesis of new borane molecules and optimization of the synthetic methods of boranes have been a significant part of boron chemistry over the last one hundred years. Herein, we have systematically summarized the syntheses of small borane molecules, polyhedral boranes, and carboranes; we also provided the molecular structures and 11B NMR spectra of borane compounds. Anticipatedly, this review will provide the basic knowledge for readers interested in borane chemistry and facilitate the readers for improving the synthetic methods of boranes and exploring the application of borane compounds.

Designing an advantageous catalyst for enhancing the release of hydrogen (H 2) from NaBH 4 hydrolysis is still desirable. Herein, a void-engineered shaggy cobalt oxide (VSCO) is constructed via facile carving and calcination using the cuboid cobalt-based metal organic framework (Co-MOF) as a template. The as-prepared VSCO shows unique structural properties, such as large internal void, high specific surface area, and abundant oxygen vacancy, enabling VSCO to boost H 2 production from NaBH 4 hydrolysis. VSCO also exhibits an activation energy (E a) of 28.9 kJ mol−1, which is much lower than that of commercial Co 3 O 4 NP (62.9 kJ mol−1) and most of recent reported noble metals. VSCO also retains its outstanding catalytic activity over multiple cycles. This work sheds a light into the new approach of constructing metal oxide material with the void structure and abundant oxygen vacancies for catalyzing the hydrolysis of NaBH 4. [Display omitted] • Void and shaggy-structured Co 3 O 4 (VSCO) is created by a facile carving treatment. • VSCO exhibits more superior textural properties than commercial Co 3 O 4 NP (CCON). • VSCO also possesses more abundant oxygen vacancies than CCON. • VSCO enables a significantly low E a of H 2 generation from NaBH 4 hydrolysis. • VSCO remains highly effective for catalyzing NaBH 4 hydrolysis over 5 cycles. [ABSTRACT FROM AUTHOR]

Direct borohydride fuel cell (DBFC) has been widely used in portable and mobile power supply because of its advantages of high theoretical cell voltage, considerable specific capacity and green environmental friendliness. Anode catalyst is the key material to improve DBFC performance and fuel efficiency. In the past, noble metals have been used as anode catalysts for DBFC batteries, but the high cost and limited resources of noble metals have limited the further development of the DBFC. At present, transition metal catalysts have received increasing attention due to their low cost and catalytic activity comparable to that of noble metals. On the basis of elucidating the working principle of DBFC, the research achievements of transition metal catalysts for DBFC in the past 20 years are reviewed in this paper. Through a large number of literature studies, it is found that the research results related to Ni-based, Co-based and their composite transition metal catalysts are the most abundant. It is also found that transition metal catalysts with nanometer size and loose structure show good catalytic activity. Therefore, Ni-based, Co-based and their composite transition metal catalysts were reviewed in detail. We believe that with the deepening of research, the proportion of transition metals in DBFC anode catalysts is increasing, which has a broader research space and application prospect. [ABSTRACT FROM AUTHOR]

Alcohols are one of the most common organic compound classes among natural and synthetic products. Thus, methods for direct removal of C−OH groups without the need for wasteful pre‐functionalization are of great synthetic interest to unlock the full synthetic potential of the compound class. Herein, electroreductive C−OH bond activation and subsequent deoxygenative C−H and C−C bond formation of benzylic and propargylic alcohols are demonstrated along with mechanistic insights. Experimental and theoretical studies indicate that the reductive C−OH bond cleavage furnishes an open shell intermediate that undergoes a radical‐polar crossover to the corresponding carbanion that subsequently undergoes protonation to furnish alkane products. Furthermore, we demonstrate that the carbanion can be trapped with CO2 to form arylacetic acids. The cathodic transformations are efficiently balanced by the anodic oxidation of sub‐stoichiometric borohydride additives, a strategy that serves as a highly attractive alternative to the use of sacrificial metal anodes. [ABSTRACT FROM AUTHOR]

The challenging metal‐free catalytic hydrogenolysis of silyl chlorides to hydrosilanes is unlocked by using an inverse frustrated Lewis pair (FLP), combining a mild Lewis acid (Cy2BCl) and a strong phosphazene base (BTPP) in mild conditions (10 bar of H2, r. t.). In the presence of a stoichiometric amount of the base, the hydrosilanes R3SiH (R=Me, Et, Ph) are generated in moderate to high yields (up to 95 %) from their chlorinated counterparts. A selective formation of the valuable difunctional monohydride Me2SiHCl is also obtained from Me2SiCl2. A mechanism is proposed based on stoichiometric experiments and DFT calculations; it highlights the critical role of borohydride species generated by the heterolytic splitting of H2. [ABSTRACT FROM AUTHOR]

In this paper, the generation of hydrogen from alkaline sodium borohydride solution by hydrolysis is studied. To obtain catalysts for efficient hydrogen generation, Ni, Mn, Mo, and Co metals were deposited on the Cu surface by the simple electroless metal deposition method using morpholine borane as a reducing agent. Depending on the peculiarities of the deposition of each metal, the coating thickness was ca. 1 μm for all catalysts. The deposited coatings were compact and crack-free, with multilayer characteristics and a cauliflower-like structure. The prepared Ni/Cu, NiMn/Cu, NiMo/Cu, NiCo/Cu, NiCoMn/Cu, NiCoMo/Cu, and NiCoMoMn/Cu catalysts showed an efficient catalytic activity for sodium borohydride hydrolysis reaction. The lowest activation energy of 45.3 kJ mol−1 for sodium borohydride hydrolysis reaction was obtained using the NiCoMoMn/Cu catalyst. The highest hydrogen generation rate of 3.08 mL min−1 was also achieved using this catalyst at 303 K. With a further increase in temperature to 343 K, the hydrogen generation rate catalyzed by the NiCoMoMn/Cu increased 7.7 times and reached 23.57 mL min−1. [ABSTRACT FROM AUTHOR]

The method to synthesize high‐capacity complex hydride nanostructures, such as borohydrides, decorated with metallic shells has surfaced as an attractive approach for enabling reversible hydrogen storage. However, the current solvent‐based synthesis methods of such core‐shell nanostructures are limited by solvents/hydrides compatibility issues and the low solubility of the shell precursor in such solvents. Herein, for the first time, an alternative solid‐state method to prepare core‐shell‐like nanostructures is reported. Simply, by mixing and heating vanadium (V)‐doped sodium borohydride (V‐NaBH4) cores and nickelocene (as nickel precursor) at 150 °C, it is possible to decorate V‐NaBH4 with Ni, which shows an improved hydrogen release (≈8 mass% H2) at 350 °C and a net reversible hydrogen capacity of 2 mass%. Detailed structural investigations reveal that the in‐situ formed VxBy and NixBy are responsible for superior hydrogen absorption in the core‐shell material, where these boride species around the shell/interfaces suppress the loss of Na or B and the formation of B12H12 during hydrogen release/uptake. This work opens solvent‐free pathways to design and control the chemical composition of core–shell (boro)hydrides for practical hydrogen storage.

Abstract Alcohols are one of the most common organic compound classes among natural and synthetic products. Thus, methods for direct removal of C−OH groups without the need for wasteful pre‐functionalization are of great synthetic interest to unlock the full synthetic potential of the compound class. Herein, electroreductive C−OH bond activation and subsequent deoxygenative C−H and C−C bond formation of benzylic and propargylic alcohols are demonstrated along with mechanistic insights. Experimental and theoretical studies indicate that the reductive C−OH bond cleavage furnishes an open shell intermediate that undergoes a radical‐polar crossover to the corresponding carbanion that subsequently undergoes protonation to furnish alkane products. Furthermore, we demonstrate that the carbanion can be trapped with CO2 to form arylacetic acids. The cathodic transformations are efficiently balanced by the anodic oxidation of sub‐stoichiometric borohydride additives, a strategy that serves as a highly attractive alternative to the use of sacrificial metal anodes.

Assessing competitive environmental catalytic reduction processes via NaBH4 is essential, as BH4− is both an energy carrier (as H2) and a reducing agent. A comprehensive catalytic study of the competition between the borohydride hydrolysis reaction (BHR, releasing H2) and 4-nitrophenol reduction via BH4− on M0- and M/M′ (alloy)-nanoparticle catalysts is reported. The results reveal an inverse correlation between the catalytic efficiency for BH4− hydrolysis and 4-nitrophenol reduction, indicating that catalysts performing well in one process exhibit lower activity in the other. Plausible catalytic mechanisms are discussed, focusing on the impact of reaction products such as 4-aminophenol and borate on the rate and yield of BH4− hydrolysis. The investigated catalysts were Ag0, Au0, Pt0, and Ag/Pt-alloy nanoparticles synthesized without any added stabilizer. Notably, the observed rate constants for the 4-nitrophenol reduction on Ag0, Ag-Pt (9:1), and Au0 are significantly higher than the corresponding rate constants for BH4− hydrolysis, suggesting that most reductions do not proceed through surface-adsorbed hydrogen atoms, as observed for Pt0 nanoparticles. This research emphasizes the conflicting nature of BH4− hydrolysis and reduction processes, provides insights for designing improved catalysts for competitive reactions, and sheds light on the catalyst properties required for each specific process. [ABSTRACT FROM AUTHOR]

We successfully fabricated a novel tensile lattice strained Ni@NiCu catalyst with a popcorn-like morphology, which is composed of a crystalline Ni core and a NiCu alloy shell. It exhibits outstanding catalytic activity, selectivity, and stability towards borohydride electrooxidation. Moreover, a direct borohydride fuel cell (DBFC) with a Ni@NiCu anode can deliver a power density of 433 mW cm−2 and an open circuit voltage of 1.94 V, much better than the performances of DBFCs employing other anode catalysts reported in the literature. This could be attributed to the fact that the tensile lattice strain generated by the introduction of Cu leads to a rise in the d-band center of the Ni metal and promotes the final B–H decoupling, which is the rate-determining step in the borohydride oxidation reaction, thus improving remarkably the catalytic performances of Ni@NiCu. [ABSTRACT FROM AUTHOR]

Borohydride reduction of dialdehyde cellulose (DAC) is a promising strategy to generate dialcohol cellulose as bio-based alternative to petroleum-based materials. However, the degradation of the polymer backbone according to β-elimination mechanisms limits the practical applications of the reaction. Therefore, we aimed at optimizing the process to suppress degradation reactions by varying reaction time, pH, and reagent stoichiometry. The degree of oxidation (DO) of the DAC intermediates significantly impacts the yields and molecular weights of the isolated dialcohol celluloses, with a "leveling-off" effect at higher DO values. Increasing the amount of sodium borohydride can minimize—but not entirely prevent—chain scissions. Lowering the pH value during reduction slows down the degradation but results in incomplete conversion of the aldehyde functionalities. Our study provides valuable insights into the consequences of side reactions during borohydride reduction of DAC as well as into chemistry and analysis of the dialdehyde cellulose/dialcohol cellulose system. About a dilemma in cellulose chemistry: Dialcohol cellulose derived by periodate oxidation and subsequent borohydride reduction of cellulose has received increasing attention in the development of sustainable thermoplastic materials. The present study highlights the challenge of suppressing β-elimination and favoring the reduction pathway to optimize reaction conditions and minimize chain degradation. [ABSTRACT FROM AUTHOR]

Herein, polyvinyl alcohol based anion exchange membranes (AEMs) doped with various cobalt and chloride salts are synthesized to investigate the structure-performance relationship of ion-doped AEMs systemically. The performances of ion-doped AEMs are found to be related to the hydrolysis degree (DH) of the doped anions and cations. It is found that cations with varying DH transformed into hydroxides with different sizes and dispersions, which plays a key role in determining the structures and properties of cation-doped AEMs. On the other hand, weak-acid anions remained in the AEMs after alkali immersion, hindering OH− conduction and leading to the degradation of the anion-doped AEMs. High DH cations mildly react with the matrix and transform into more dispersive complexes, while low DH anions are replaced by OH−.The direct borohydride fuel cell using CuCl 2 -doped AEM exhibits a maximum power density of 202.4 mW cm−2 at 30 °C. [Display omitted] • The properties of ion-doped AEMs are effected by the DH of doped-ions. • Cations transform into hydroxides with various sizes in the cation-doped AEM. • Weak-acid anions stay in the anion-doped AEM and hinder the OH− conduction. • Mildbase strong-acid salts are concluded as the most promising ionic additives. [ABSTRACT FROM AUTHOR]

Tetramethylphosphonium borohydride was synthesized via an ion metathesis reaction in a weakly-coordinating aprotic environment. [(CH3)4P]BH4, in contrast to related [(CH3)4N]+ compounds which tend to crystallize in a tetragonal system, adopts the distorted wurtzite structure (P63mc), resembling some salts containing analogous ions of As and Sb. [(CH3)4P]BH4 decomposes thermally in several endo- and exothermic steps above ca. 240 °C. This renders it more stable than [(CH3)4N]BH4, with a lowered temperature of decomposition onset by ca. 20 °C and solely exothermic processes observed. Raman spectra measured at the 0–10 GPa range indicate that a polymorphic transition occurs within 0.53–1.86 GPa, which is further confirmed by the periodic DFT calculations. The latter suggests a phase transition around 0.8 GPa to a high-pressure phase of [(CH3)4N]BH4. The P63mc phase seems to be destabilized under high pressure by relatively closer dihydrogen interactions, including the C–H...H–C contacts. [ABSTRACT FROM AUTHOR]

Aqueous-phase catalyzed reduction of organic contaminants via zerovalent copper nanoparticles (nCu0), coupled with borohydride (hydrogen donor), has shown promising results. So far, the research on nCu0 as a remedial treatment has focused mainly on contaminant removal efficiencies and degradation mechanisms. Our study has examined the effects of Cu0/Cun+ ratio, surface poisoning (presence of chloride, sulfides, humic acid (HA)), and regeneration of Cu0 sites on catalytic dechlorination of aqueous-phase 1,2-dichloroethane (1,2-DCA) via nCu0-borohydride. Scanning electron microscopy confirmed the nano size and quasi-spherical shape of nCu0 particles. X-ray diffraction confirmed the presence of Cu0 and Cu2O and x-ray photoelectron spectroscopy also provided the Cu0/Cun+ ratios. Reactivity experiments showed that nCu0 was incapable of utilizing H2 from borohydride left over during nCu0 synthesis and, hence, additional borohydride was essential for 1,2-DCA dechlorination. Washing the nCu0 particles improved their Cu0/Cun+ ratio (1.27) and 92% 1,2-DCA was removed in 7 h with kobs = 0.345 h−1 as compared to only 44% by unwashed nCu0 (0.158 h−1) with Cu0/Cun+ ratio of 0.59, in the presence of borohydride. The presence of chloride (1000–2000 mg L−1), sulfides (0.4–4 mg L−1), and HA (10–30 mg L−1) suppressed 1,2-DCA dechlorination; which was improved by additional borohydride probably via regeneration of Cu0 sites. Coating the particles decreased their catalytic dechlorination efficiency. 85–90% of the removed 1,2-DCA was recovered as chloride. Chloroethane and ethane were main dechlorination products indicating hydrogenolysis as the major pathway. Our results imply that synthesis parameters and groundwater solutes control nCu0 catalytic activity by altering its physico-chemical properties. Thus, these factors should be considered to develop an efficient remedial design for practical applications of nCu0-borohydride. [ABSTRACT FROM AUTHOR]

The transition to a hydrogen economy is a must in any carbon-emissions-free future scenario. One practical challenge of this transition is the safety concern when using large amounts of compressed or liquid hydrogen. This can be averted by using solid salts, such as potassium borohydride (KBH4), as hydrogen carriers for industrial applications. Many metals and oxides catalyse this reaction, but the challenge lies in the catalysts' stability. The combination of high pH and fast hydrogen generation causes mechanical degradation. Here we show that chitosan, an abundant biobased polymer, is a practical and effective catalyst support for KBH hydrolysis. We form chitosan spheres that encapsulate the active cobalt catalyst species, all done under ambient conditions. They remain stable at the high reaction pH, and swell and shrink with the formation of hydrogen. The catalyst can be reused several times in both batch and continuous modes. A continuous test using a 5 w/w% stabilised fuel solution and only 250 mg catalyst generated hydrogen at an average rate of 32 mL min−1 over 48 h. Studying the reaction kinetics using high-precision measurements, we observe a kink in the Arrhenius plot, reflecting a physical change in the system (the swelling of the spheres) rather than a change in mechanism. Comparison studies show that the flexible biopolymer support outperforms classic porous oxide supports such as alumina, magnesia, and alumina-magnesia. Our research shows a clear green advance, based on multi-factor comparison: First, our system enables safe hydrogen transportation and on-demand release (low hazard and enables clean energy). Second, it uses a renewable and abundant bio-based source and no noble metals (no resource depletion). Finally, it requires only simple preparation under ambient conditions and at a low cost (practical application). All these make the encapsulation in flexible chitosan spheres an attractive approach to sustainable catalysts for carbon-free fuels. [ABSTRACT FROM AUTHOR]

Regulating the electronic structure of noble metals through metal alloy–support interactions is significant for hydrogen economy. Herein, a PdAg alloy highly dispersed on the surface of Ti 3 C 2 is successfully designed through a simple microwave-assisted reduction method. The catalytic activity of PdAg alloys with various molar ratios manifests obviously enhanced catalytic activity compared to monometallic catalysts toward hydrogen generation in ammonia borane (AB) hydrolysis. Specifically, Pd 4 Ag 1 /Ti 3 C 2 presents an optimal turnover frequency (TOF) value of 1296 min−1 at room temperature and a lower activation energy (E a) of 38.8 kJ mol-1. Through the experimental results, the formation of a PdAg alloy with the introduction of the second metal Ag adjusts the electronic structure around Pd and enhances the catalytic activity. Additionally, the metal alloy–support interaction between Ti 3 C 2 and the PdAg alloy significantly promotes hydrogen generation during the hydrolysis of AB. This study provides new ideas and a reasonable basis for heterogeneous catalysis based on bimetallic catalysts. A PdAg alloy highly dispersed on the surface of Ti 3 C 2 is successfully designed through a simple microwave-assisted reduction method. The catalytic activity of PdAg alloys with various molar ratios manifests obviously enhanced catalytic activity compared to monometallic catalysts toward hydrogen generation in ammonia borane (AB) hydrolysis. Specifically, Pd 4 Ag 1 /Ti 3 C 2 presents an optimal turnover frequency (TOF) value of 1296 min−1 at room temperature and a lower activation energy (E a) of 38.8 kJ mol−1. Through the experimental results, the formation of a PdAg alloy with the introduction of the second metal Ag adjusts the electronic structure around Pd and enhances the catalytic activity. Additionally, the metal alloy–support interaction between Ti 3 C 2 and the PdAg alloy significantly promotes hydrogen generation during the hydrolysis of AB. This study provides new ideas and a reasonable basis for heterogeneous catalysis based on bimetallic catalysts. [Display omitted] [ABSTRACT FROM AUTHOR]

We report two bifunctional (pyridyl)carbene-iridium(I) complexes that catalyze ketone and aldehyde hydrogenation at ambient pressure. Aryl, heteroaryl, and alkyl groups are demonstrated, and mechanistic studies reveal an unusual polarization effect in which the rate is dependant of proton, rather than hydride, transfer. This method introduces a convenient, waste-free alternative to traditional borohydride and aluminum hydride reagents. [ABSTRACT FROM AUTHOR]

New syntheses have been developed for the synthesis of (borohydrido-κ3 H)tris-[η5-(tri-methyl-sil-yl)cyclo-penta-dien-yl]uranium(IV), [U(BH4)(C8H13Si)3] or Cp'3U(BH4) (Cp' = C5H4SiMe3) and its structure has been determined by single-crystal X-ray crystallography. This compound crystallized in the space group P and the structure features three η 5-coordinated Cp' rings and a κ 3-coordinated (BH4)- ligand.

Hydrogenous materials are of great interest in nuclear industry because of the ability of hydrogen to slow-down neutrons. In comparison with common hydrogenous materials, metal hydrides highly enriched with hydrogen at high temperatures and good mechanical properties. This study concerns on evaluation the requirements for photons, charged particles and fast neutrons shielding parameters for several types of hydride and borohydride metals. Firstly, photons shielding ability of these materials were examined using Phy-X/PSD program. Assigning the attenuation factors of photons were evaluated for an energy range (1 keV–100 GeV). Secondly, the charged particle (electron, proton and alpha particle) interactions were examined by using ESTAR (Stopping Powers and Ranges for Electrons) and SRIM (The Stopping and Range of Ions in Matter) programs. Finally, fast neutron attenuation was tested by calculating the removal cross-sections (ΣR) for neutron with energy 4.5 MeV. The dependence of photons, charged particles and fast neutrons parameters on the constituent of tested samples was given and discussed. The obtained results through this work show that, the shielding proficiency parameters depend on the energy of the incident radiation and chemical constituents of the examined materials. As well as, these results showed that BaH2, ZrH2, VH2 and TiH2 samples own a good shielding performance compared to the other investigated samples.

Sodium borohydride (NaBH4) has been a material of interest for many years in developing metal boride complexes and shows a great deal of potential as a hydrogen storage material. Though many have used various additives as catalysts to weaken the bonds within NaBH4 to create a more energetically favorable material, very little is understood about how the borohydride interacts with and changes the additives being incorporated. This work uses ball milling to incorporate calcium chloride (CaCl2) into NaBH4. Using several x-ray techniques, thermogravimetric analysis, and Raman spectroscopy, this study shows not only that the salt diffuses into NaBH4 but describes how the borohydride changes the additive itself. In gaining a stronger understanding of what happens to the additives needed to weaken the borohydride bonds, future researchers may have an easier time selecting the appropriate additive to create a borohydride complex that will meet their needs.

Sodium borohydride (NaBH4) has been a material of interest for many years in developing metal boride complexes and shows a great deal of potential as a hydrogen storage material. Though many have used various additives as catalysts to weaken the bonds within NaBH4 to create a more energetically favorable material, very little is understood about how the borohydride interacts with and changes the additives being incorporated. This work uses ball milling to incorporate calcium chloride (CaCl2) into NaBH4. Using several x-ray techniques, thermogravimetric analysis, and Raman spectroscopy, this study shows not only that the salt diffuses into NaBH4 but describes how the borohydride changes the additive itself. In gaining a stronger understanding of what happens to the additives needed to weaken the borohydride bonds, future researchers may have an easier time selecting the appropriate additive to create a borohydride complex that will meet their needs.

The coordination chemistry of scorpionate ligands based on borates containing the 7-azaindole heterocycle is relatively unexplored. Thus, there is a requirement to further understand their coordination chemistry. This article outlines the synthesis and characterization of a family of complexes containing anionic flexible scorpionate ligands of the type [(R)(bis-7-azaindolyl)borohydride]− ([RBai]−), where R = Me, Ph or naphthyl. The three ligands were coordinated to a series of copper(I) complexes containing a phosphine co-ligand to form the complexes, [Cu(MeBai)(PPh3)] (1), [Cu(PhBai)(PPh3)] (2), [Cu(NaphthBai)(PPh3)] (3), [Cu(MeBai)(PCy3)] (4), [Cu(PhBai)(PCy3)] (5) and [Cu(NaphthBai)(PCy3)] (6). Additional copper(II) complexes, namely, [Cu(MeBai)2] (7) and [Cu(PhBai)2] (8), were obtained during attempts to obtain single crystals from complexes 4 and 2, respectively. Complexes 7 and 8 were also prepared independently from CuCl2 and two equivalents of the corresponding Li[RBai] salt alongside an additional complex, namely, [Cu(NaphthBai)2] (9). The copper(I) and copper(II) complexes were characterized using spectroscopic and analytical methods. Furthermore, a crystal structure was obtained for eight of the nine complexes. In all cases, the boron-based ligand was found to bind to the metal centers via a κ3-N,N,H coordination mode. [ABSTRACT FROM AUTHOR]