We describe the successful synthesis of the first mixed-cation (pseudoternary) amidoborane, Na[Li(NH(2)BH(3))(2)], with theoretical hydrogen capacity of 11.1 wt%. Na[Li(NH(2)BH(3))(2)] crystallizes triclinic (P1) with a = 5.0197(4) Å, b = 7.1203(7) Å, c = 8.9198(9) Å, α = 103.003(6)°, β = 102.200(5)°, γ = 103.575(5)°, and V = 289.98(5) Å(3) (Z = 2), as additionally confirmed by Density Functional Theory calculations. Its crystal structure is topologically different from those of its orthorhombic LiNH(2)BH(3) and NaNH(2)BH(3) constituents, with distinctly different coordination spheres of Li (3 N atoms and 1 hydride anion) and Na (6 hydride anions). Na[Li(NH(2)BH(3))(2)], which may be viewed as a product of a Lewis acid (LiNH(2)BH(3))/Lewis base (NaNH(2)BH(3)) reaction, is an important candidate for a novel lightweight hydrogen storage material. The title material decomposes at low temperature (with onset at 75 °C, 6.0% mass loss up to 110 °C, and an additional 3.0% up to 200 °C) while evolving hydrogen contaminated with ammonia.

SignificanceAntiferromagnets can host strong quantum fluctuations in their ground state if they combine both low dimensionality and low spin. Materials based on copper oxides (spin-1/2 ions in layered or 1D structures) are unique in optimizing the tendency to strong quantum fluctuations. As a bonus, they show extremely large magnetic interactions, which lead to interesting quantum effects at relatively high temperatures as anomalous transport properties and high-Tc superconductivity in doped systems. Obtaining similar features with other ions has been a long-standing goal. We show that silver and fluorine (which are next to copper and oxygen in the periodic table) in the commercial compound normalAnormalgnormalF2 reach the goal, paving the way for a different generation of quantum materials.

A combined experimental-theoretical study of silver(I) and silver(II) fluorides under high pressure is reported. For Ag, the CsCl-type structure is stable to at least 39 GPa; the overtone of the IR-active mode is seen in the Raman spectrum. Its AgF sibling is a unique compound in many ways: it is more covalent than other known difluorides, crystallizes in a layered structure, and is enormously reactive. Using X-ray diffraction and guided by theoretical calculations (density functional theory), we have been able to elucidate crystal structures of high-pressure polymorphs of AgF. The transition from ambient pressure to an unprecedented nanotubular structure takes place via an intermediate orthorhombic layered structure, which lacks an inversion center. The observed phase transitions are discussed within the broader framework of the fluorite → cotunnite → NiIn series, which has been seen for other metal difluorides.

Black AgSO4, synthesized for the first time by a displacement reaction, differs considerably from anhydrous sulfates of its Group 11 congeners: it has a very small electronic band gap (ca. 0.2 eV) and an anomalously strong one‐dimensional antiferromagnetic ordering ( J≈10 meV per Ag), which persists up to the onset of its thermal decomposition at about 120 °C. Ag gray, O red, S yellow.

The thermo-elastic behaviour of synthetic single crystals of grossular garnet (Ca 3 Al 2 Si 3 O 12 ) has been studied in situ as a function of pressure and temperature separately. The same data collection protocol has been adopted to collect both the pressure-volume (P-V) and temperature-volume (T-V) datasets in order to make the measurements consistent with one another. The consistency between the two datasets allows simultaneous fitting to a single pressure-volume-temperature equation of state (EoS), which was performed with a new fitting utility implemented in the latest version of the program EoSFit7c. The new utility performs fully weighted simultaneous fits of the P-V-T and P-K-T data using a thermal pressure Equation of State combined with any PV EoS. Simultaneous refinement of our P-V-T data combined with that of K T as a function of T allowed us to produce a single P-V-T-K T equation of state with the following coefficients:V 0 = 1664.46(5) Å 3 , K T0 = 166.57(17) GPa and K` = 4.96(7) α (300K, 1bar) = 2.09(2)*10 -5 K -1 with a refined Einstein temperature (θ E ) of 512K for a Holland-Powell-type thermal pressure model and a Tait 3 rdorder EoS. Additionally, thermodynamic properties of grossular have been calculated for the first time from crystal Helmholtz and Gibbs energies, including the contribution from phonons, using density functional theory within the framework of the quasi-harmonic approximation.

Tiefschwarzes AgSO4 (Mr. Hyde) ist ein Halbleiter mit schmaler Bandlücke und ein extrem starkes Oxidationsmittel. W. Grochala und Mitarbeiter zeigen in ihrer Zuschrift auf dass AgSO4 in praktisch allen physikochemischen Eigenschaften von seinem leichteren Verwandten, dem unreaktiven und farblosen CuSO4 (Dr. Jekyll), abweicht. Die ungewöhnlich starke antiferromagnetische Kopplung bleibt bis zur Zersetzungstemperatur (ca. 120 °C) erhalten, wodurch es sich auch von allen anderen Übergangsmetallsulfaten unterscheidet.

Meta-GGA calculations of the ambient and high-pressure polymorphs of silver difluoride indicate that the compression-induced structural changes lead to a 3.5-fold increase in the strength of antiferromagnetic spin-spin interactions resulting in coupling constant values higher than those found for record-holding oxocuprates(ii).

] in a structure type related to that of AgF 2 . Puckered [Ag(SO 3 F) 2 ] sheets are present in the crystal structure with two oxygen atoms of the fluorosulfate anions utilized for bonding within the sheet; the third oxygen atom serves as a linker to the adjacent sheet. Terminal fluorine atoms form small cavities in the structure. The S-O stretching region of the vibrational (IR and Raman) spectra is rich in bands, thus confirming the structural complexity of Ag(SO 3 F) 2 . Ag(SO 3 F) 2 is a soft ferromagnet with a Curie temperature of 24.8 K and it shows a single broad electron spin resonance (ESR) with g = 2.183 at T = 293 K. The intrasheet magnetic superexchange constant, J, derived from