Aliovalent anion substitution as a design concept for heteroanionic Ruddlesden-Popper hydrides.

Substituting 2 O ⇒ N + H in LiLaHO yields dark-brown heteroanionic hydrides, which were synthesized by solid-state reactions from LiN, LaH (and LaO). They crystallize in the KNiF type structure with mixed H/N sites in LiLaNH and with mixed N/O sites in LiLaNHO. The latter is a semiconductor with small band gap and partly covalent Li-H interaction.

Structure of crystalline and amorphous materials in the NASICON system NaAlGe(PO).

The structure of crystalline and amorphous materials in the sodium (Na) super-ionic conductor system NaAlGe(PO) with x = 0, 0.4, and 0.8 was investigated by combining (i) neutron and x-ray powder diffraction and pair-distribution function analysis with (ii) Al and P magic angle spinning (MAS) and P/Na double-resonance nuclear magnetic resonance (NMR) spectroscopy.

YHO, an Air-Stable Ionic Hydride.

Metal hydride oxides are an emerging field in solid-state research. While some lanthanide hydride oxides (HO) were known, YHO has only been found in thin films so far. Yttrium hydride oxide, YHO, can be synthesized as bulk samples by a reaction of YO with hydrides (YH, CaH), by a reaction of YH with CaO, or by a metathesis of YOF with LiH or NaH.

Determination of element-deuterium bond lengths in Zintl phase deuterides by H-NMR.

The Zintl phase deuterides CaSiD, SrSiD, BaSiD, SrGeD, BaGeD and BaSnD were investigated by nuclear magnetic resonance (NMR) spectroscopy and density functional theory (DFT) calculations to reliably determine element-deuterium bond lengths. These compounds show deuterium bound to the polyanion and deuteride ions in tetrahedral cationic voids. With H-NMR experiments we characterised the individual signals of the two distinct crystal sites.

Structural and Electronic Flexibility in Hydrides of Zintl Phases with Tetrel-Hydrogen and Tetrel-Tetrel Bonds.

The hydrogenation of Zintl phases enables the formation of new structural entities with main-group-element-hydrogen bonds in the solid state. The hydrogenation of SrSi, BaSi, and BaGe yields the hydrides SrSiH BaSiH and BaGeH . The crystal structures show a sixfold superstructure compared to the parent Zintl phase and were solved by a combination of X-ray, neutron, and electron diffraction and the aid of DFT calculations.

Hydrides of Alkaline Earth-Tetrel (AeTt) Zintl Phases: Covalent Tt-H Bonds from Silicon to Tin.

Zintl phases form hydrides either by incorporating hydride anions (interstitial hydrides) or by covalent bonding of H to the polyanion (polyanionic hydrides), which yields a variety of different compositions and bonding situations. Hydrides (deuterides) of SrGe, BaSi, and BaSn were prepared by hydrogenation (deuteration) of the CrB-type Zintl phases AeTt and characterized by laboratory X-ray, synchrotron, and neutron diffraction, NMR spectroscopy, and quantum-chemical calculations. SrGeD and BaSnD show condensed boatlike six-membered rings of Tt atoms, formed by joining three of the zigzag chains contained in the Zintl phase.

In Situ Hydrogenation of the Zintl Phase SrGe.

Hydrides (deuterides) of the CrB-type Zintl phases AeTt (Ae = alkaline earth; Tt = tetrel) show interesting bonding properties with novel polyanions. In SrGeD (γ phase), three zigzag chains of Ge atoms are condensed and terminated by covalently bound D atoms. A combination of in situ techniques (thermal analysis and synchrotron and neutron powder diffraction) revealed the existence of two further hydride (deuteride) phases with lower H (D) content (called α and β phases).

Electrophile-induced nucleophilic substitution of the nido-dicarbaundecaborate anion nido-7,8-C2B9H12- by conjugated heterodienes.

Substitution of the dicarbaundecaborate anion nido-7,8-C2B9H12(-) (1) by precise hydride abstraction followed by nucleophilic attack usually leads to symmetric products 10-R-nido-7,8-C2B9H11. However, thioacetamide (MeC(S)NH2) as nucleophile and acetone/AlCl3 as hydride abstractor gave asymmetric 9-[MeC(NHiPr)S]-nido-7,8-C2B9H11 (2), whereas N,N-dimethylthioacetamide (MeC(S)NMe2) gave the expected symmetric 10-[MeC(NMe2)S]-nido-7,8-C2B9H11 (4). For the formation of 2, acetone and thioacetamide are assumed to give the intermediate MeC(S)N(CMe2) (3), which then attacks 1 with formation of 2.

Experimental boundaries of the quantum rotor induced polarization (QRIP) in liquid state NMR.

The Haupt-effect is a rather seldom used hyperpolarization method. It is based on the interdependence between nuclear spin states and rotational states of nearly free rotating methyl groups having C3 symmetry. A sudden change in temperature from 4.