Small-pore hydridic frameworks store densely packed hydrogen.

Nanoporous materials have attracted great attention for gas storage, but achieving high volumetric storage capacity remains a challenge. Here, by using neutron powder diffraction, volumetric gas adsorption, inelastic neutron scattering and first-principles calculations, we investigate a magnesium borohydride framework that has small pores and a partially negatively charged non-flat interior for hydrogen and nitrogen uptake. Hydrogen and nitrogen occupy distinctly different adsorption sites in the pores, with very different limiting capacities of 2.

Nanomechanical properties of SSTSAA microcrystals are dominated by the inter-sheet packing.

Amyloid fibrils have been associated with human disease for many decades, but it has also become apparent that they play a functional, non-disease-related role in e.g. bacteria and mammals.

Structural insight into the magnesium borohydride - ethylenediamine solid-state Mg-ion electrolyte system.

A highly complex crystal structure of stoichiometric Mg()(BH) was solved from single crystal synchrotron X-ray diffraction and confirmed by neutron powder diffraction (NPD) on isotopically substituted Mg()(BD). We highlight the role of the amorphous Mg(BH) in the reactivity of the Mg(BH)- system and characterized a previously overlooked phase, Mg()(BH).

High Yield Autoclave Synthesis of pure MBH (M = Na, K).

Metal dodecaborates (MBH) are a versatile class of materials used in polymer chemistry and cancer treatment and are promising candidates as electrolytes for solid-state batteries. However, a general and scalable approach has not yet been developed for producing high-purity BH derivatives. In this work, we report a simple, efficient, and environmentally benign solvothermal method to prepare diffraction and B NMR pure NaBH (85% yield) and KBH (84% yield).

Trinuclear Magnesium Imidazolate Borohydride Complex.

A new type of hybrid compound, combining properties of MOFs and borohydrides, was synthesized solvothermally using Mg(BH) and imidazole as precursors. Material in the form of acetonitrile solvate with formula [Mg{(Im)BH(Im)}(ImH)]·CHCN crystallizes in the space group 3̅, having the unit cell parameters = 15.1942(2) Å and = 28.

Synthesis, Structure, and Thermal Stability of a Mesoporous Titanium(III) Amine-Containing MOF.

The first mesoporous bimetallic Ti/Al metal-organic framework (MOF) containing amine functionalities on its linkers has been selectively obtained by converting the cheap commercially available (TiCl)AlCl into TiAlCl(THF) and reacting this complex with 2-aminoterephthalic acid in dimethylformamide (DMF) under soft solvothermal conditions. This compound is structurally related to the previously described NH-MIL-101(M) (M = Cr, Al, and Fe) MOFs. Thermal gravimetric analyses and powder X-ray diffraction (PXRD) measurements demonstrated that this highly air-sensitive Ti-containing MOF is structurally stable up to 200 °C.

Abrupt change from moderate positive to colossal negative thermal expansion caused by imidazolate composite formation.

Unlabelled: This work describes temperature-induced crystallization processes and reaction mechanisms occurring in the borohydride-imidazolate system. In the course of thermal evolution, crystal structures of two novel bimetallic imidazolates AMnIm (A = Na, K) were solved using synchrotron radiation powder diffraction data. Both the alkali metal cation and the Mn cations exhibit distorted octahedral coordination while each imidazolate is surrounded by two alkali metal and two manganese atoms.

Functionalization of Mono- and Bimetallic MIL-100(Al,Fe) MOFs by Ethylenediamine: Postfunctionalization, Brønsted Acido-Basicity, and Unusual CO Sorption Behavior.

The metal sites of MIL-100(Fe), MIL-100(Fe,Al), and MIL-100(Al) metal-organic frameworks (MOFs) were decorated with ethylenediamine (EN). Interestingly, the Al-containing MOFs presented hierarchized porosity, and their structural integrity was maintained upon functionalization. Solution and solid-state NMR confirmed the grafting efficiency in the case of MIL-100(Al) and the presence of a free amine group.

Kinetic Barriers and Microscopic Mechanisms of Noble Gas Adsorption by Nanoporous γ-Mg(BH ) Obtained by Means of Sub-Second X-Ray Diffraction.

Gas adsorption by porous frameworks sometimes results in structure "breathing", "pores opening/closing", "negative gas adsorption", and other phenomena. Time-dependent diffraction can address both kinetics of the guest uptake and structural response of the host framework. Using sub-second in situ powder X-ray diffraction, three intracrystalline diffusion scenarios have been evaluated from the isothermal kinetics of Ar, Kr, and Xe adsorption by nanoporous γ-Mg(BH ) .

Mechanochemical defect engineering of HKUST-1 and impact of the resulting defects on carbon dioxide sorption and catalytic cyclopropanation.

Metal-organic frameworks (MOFs) are recognized as ideal candidates for many applications such as gas sorption and catalysis. For a long time the properties of these materials were thought to essentially arise from their well-defined crystal structures. It is only recently that the importance of structural defects for the properties of MOFs has been evidenced.

Exploring the solid-state phases and thermodynamics of calcium l-lactate.

Calcium l-lactate, an organic salt derived from l-lactic acid, is used in many fields such as food, pharmaceutical or cosmetic industry. To this date, its solid-state thermodynamics are still poorly understood: a pentahydrate crystalline and anhydrate amorphous forms were already characterized, and potential other hydrates mentioned in literature. For the development of a robust crystallization process or down-line handling of this compound, it is important to know and understand the relationship between the different solid forms to prevent uncontrolled crystallization or solid-solid transformation during storage.

Non-Isothermal Kinetics of Kr Adsorption by Nanoporous γ-Mg(BH) from in Situ Synchrotron Powder Diffraction.

Crystalline materials with pore dimensions comparable to the kinetic diameters of the guest molecules are attractive for their potential use in adsorption and separation applications. The nanoporous γ-Mg(BH) features one-dimensional channels matching this criterion for Kr uptake, which has been probed using synchrotron powder diffraction at various pressures and temperatures. It results in two coexisting crystalline phases with the limiting composition Mg(BH)·0.

Engineering Structural Dynamics of Zirconium Metal-Organic Frameworks Based on Natural C4 Linkers.

Engineering the structural flexibility of metal-organic framework (MOF) materials for separation-related applications remains a great challenge. We present here a strategy of mixing rigid and soft linkers in a MOF structure to achieve tunable structural flexibility, as exemplified in a series of stable isostructural Zr-MOFs built with natural C4 linkers (fumaric acid, succinic acid, and malic acid). As shown by the differences in linker bond stretching and bending freedom, these MOFs display distinct responsive dynamics to external stimuli, namely, changes in temperature or guest molecule type.

Mechanochemistry of Metal Hydrides: Recent Advances.

This paper is a collection of selected contributions of the that was held in Oslo in May 2018. In this paper, the recent developments in the use of mechanochemistry to synthesize and modify metal hydrides are reviewed. A special emphasis is made on new techniques beside the traditional way of ball milling.

SrCrN: A New Electride with a Partially Filled -Shell Transition Metal.

Electrides are ionic crystals in which the electrons prefer to occupy free space, serving as anions. Because the electrons prefer to be in the pockets, channels, or layers to the atomic orbitals around the nuclei, it has been challenging to find electrides with partially filled shell transition metals, since an unoccupied shell provides an energetically favorable location for the electrons to occupy. We recently predicted the existence of electrides with partially filled shells using high-throughput computational screening.

Mixed-Metal Imidazolates Containing Alkali and Alkaline Earth Metals: Mechanochemical Synthesis and Crystal Structure of AMgIm (A = Na or K).

The first bimetallic imidazolates containing alkali and alkaline earth metals, NaMgIm and KMgIm, respectively, are prepared by mechanochemical synthesis and are reported in this paper. NaMgIm has been prepared by the reaction between NaIm and Mg(BH) as well as directly from NaIm and MgIm. Structural evolution and thermal stability were followed by an in situ high-temperature X-ray powder diffraction experiment utilizing synchrotron radiation.

Complexation of Ammonia Boranes with Al.

Ammonia borane, NHBH (AB), is very attractive for hydrogen storage; however, it dehydrogenates exothermally, producing a mixture of polymeric products with limited potential for direct rehydrogenation. Recently, it was shown that AB complexed with Al in Al(BH)·AB endothermically dehydrogenates to a single product identified as Al(BH)·NHBH, with the potential for direct rehydrogenation of AB. Here we explore the reactivity of AB-derived RNHBH (R = -CH, -CH-) with AlX salts (X = BH, Cl), aiming to extend the series to different anions and to enlarge the stability window for Al(BH)·NRBH.

Low-Temperature Rotational Tunneling of Tetrahydroborate Anions in Lithium Benzimidazolate-Borohydride Li(bIm)BH.

To investigate the dynamical properties of the novel hybrid compound, lithium benzimidazolate-borohydride Li(bIm)BH (where bIm denotes a benzimidazolate anion, CNH ), we have used a set of complementary techniques: neutron powder diffraction, ab initio density functional theory calculations, neutron vibrational spectroscopy, nuclear magnetic resonance, neutron spin echo, and quasi-elastic neutron scattering. Our measurements performed over the temperature range from 1.5 to 385 K have revealed the exceptionally fast low-temperature reorientational motion of BH anions.

Gravimetric tank method to evaluate material-enhanced hydrogen storage by physisorbing materials.

The most common methods to evaluate hydrogen sorption (volumetric and gravimetric) require significant experience and expensive equipment for providing reproducible results. Both methods allow one to measure excess uptake values which are used to calculate the total amount of hydrogen stored inside of a tank as required for applications. Here we propose an easy to use and inexpensive alternative approach which allows one to evaluate directly the weight of hydrogen inside a material-filled test tank.

Innovative in Situ Ball Mill for X-ray Diffraction.

The renewed interest of mechanochemistry as an ecofriendly synthetic route has inspired original methodologies to probe reactions, with the aim to rationalize unknown mechanisms. Recently, Friščić et al. ( Nat.

Solid Aluminum Borohydrides for Prospective Hydrogen Storage.

Metal borohydrides are intensively researched as high-capacity hydrogen storage materials. Aluminum is a cheap, light, and abundant element and Al can serve as a template for reversible dehydrogenation. However, Al(BH ) , containing 16.

Mechanochemical Synthesis of PEDOT:PSS Hydrogels for Aqueous Formulation of Li-Ion Battery Electrodes.

Water-soluble binders can enable greener and cost-effective Li-ion battery manufacturing by eliminating the standard fluorine-based formulations and associated organic solvents. The issue with water-based dispersions, however, remains the difficulty in stabilizing them, requiring additional processing complexity. Herein, we show that mechanochemical conversion of a regular poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) water-based dispersion produces a hydrogel that meets all the requirements as binder for lithium-ion battery electrode manufacture.

Cooperative Adsorption by Porous Frameworks: Diffraction Experiment and Phenomenological Theory.

Materials science of metal open frameworks is a state-of-the-art field for numerous applications, such as gas storage, sensors, and medicine. Two nanoporous frameworks, γ-Mg(BH ) and MIL-91(Ti), with different levels of structural flexibility, were examined with in situ X-ray diffraction guest adsorption-desorption experiments. Both frameworks exhibit a cooperative guest adsorption correlated with a lattice deformation.

Synthesis, structures and thermal decomposition of ammine MBH complexes (M = Li, Na, Ca).

A series of ammine metal-dodecahydro-closo-dodecaboranes, MBH·nNH (M = Li, Na, Ca) were synthesized and their structural and thermal properties studied with in situ time-resolved synchrotron radiation powder X-ray diffraction, thermal analysis, Fourier transformed infrared spectroscopy, and temperature-programmed photographic analysis. The synthesized compounds, LiBH·7NH, NaBH·4NH and CaBH·6NH, contain high amounts of NH, 43.3, 26.