Crystalline samples of carbon-doped CaB4 were synthesized by solid-state reactions in sealed niobium ampules from the elements Ca, B, and C. The structure was determined by single-crystal X-ray diffraction (P4/mbm, Z = 4, a = 7.0989(7) A, c = 4.1353(5) A, R1 = 0.026, and wR2 = 0.058) revealing an atom arrangement containing a three-dimensional boron network built up from B6 octahedra and B2 dumbbells which is well-known from the structures of rare earth tetraborides. Crystals of CaB(4-x)Cx are black with a metallic luster and behave stable against mineral acids. Band structure calculations indicate that CaB4 is a stable semiconducting compound with a narrow band gap and that carbon should not necessarily be required for the stability of this compound. The presence of carbon in the crystalline samples of CaB(4-x)Cx was indicated by electron energy loss spectroscopy, but the carbon content in the samples was estimated to be less than 5% according to inductively coupled plasma-atomic emission spectrometry measurements. The distribution of boron and carbon atoms in the structure was investigated by means of 11B and 13C solid-state magic angle spinning NMR. Measurements of the magnetic susceptibility indicate a temperature-independent paramagnetism down to 20 K.

Crystals of Li[N(CN)2] were synthesized from a metathesis reaction of stoichiometric amounts of aqueous solutions of Na[N(CN)2] and Li2[SO4] followed by subsequent treatment with ethanol and evaporation of the filtered‐off solution at 80 °C under normal atmospheric conditions. The single crystals of the title compound are transparent, colorless, and extremly hygroscopic. X‐ray structure analysis showed that Li[N(CN)2] crystallizes in the monoclinic space group P2/c with the cell parameters a = 530.79(8) pm, b = 524.89(9) pm, c = 1149.77(17) pm, β = 101.551(7)°, and Z = 4. The crystal structure contains Li+ cations in both tetrahedral and octahedral nitrogen coordination of the boomerang‐shaped [N≡C–N–C≡N]– anions. The vibrational spectra of Li[N(CN)2] are reported as well, together with ab initio calculations for geometry and harmonic frequencies of the free dicyanamide anion.

Investigations of the nitridoborates of lanthanides (Ln) have progressed significantly during the last few years. New compounds have been synthesized and characterized and are presented here together with some of their properties. Currently two distinct methods serve for the preparation of nitridoborate compounds; either hexagonal boron nitride undergoes a fragmentation through the reaction with LnN, or dinitridoborate ions are converted into other nitridoborate ions. Lanthanide nitridoborates contain molecular anions such as [BN]n-, [BN2]3-, [B2N4]8-, [B3N6]9-, and [BN3]6- which may occur in combinations with other nitridoborates or with additional nitride ions. In crystal structures of lanthanide nitridoborates these anions are arranged in layers and are surrounded by metal atoms in a characteristic fashion. Terminal N atoms are capped by metal atoms forming a square-pyramid, and B atoms prefer a trigonal-prismatic environment of metal atoms. Nitridoborates form saltlike as well as metal-rich compounds and have the potential to show a lot of what are considered to be important solid-state properties, thus they have a good chance to establish their position within the group of relevant materials.

Synthesis and Crystal Structure of the Lithium Strontium Hydride Nitride LiSr2H2N LiSr2H2N was synthesized by the reaction of LiH and Li3N with elemental strontium in sealed tantalum tubes at 650 °C within seven days. This second example of a quaternary hydride nitride crystallizes orthorhombically in space group Pnma (no. 62) with the lattice constants a = 747.14(5) pm, b = 370.28(3) pm and c = 1329.86(9) pm (Z = 4). Its crystal structure contains both kinds of anions H− and N3− in a sixfold distorted octahedral metal cation coordination each. The coordination polyhedra [(H1)Sr5Li]10+, trans‐[(H2)Sr4Li2]9+ and [NSr5Li]8+ are connected via edges and corners to form a three‐dimensional network. Two crystallographically different Sr2+ cations exhibit a sevenfold monocapped trigonal prismatic coordination by H− and N3− with [(Sr1)H5N2]9− and [(Sr2)H4N3]11− polyhedra, wheras Li+ shows a nearly planar fourfold coordinative environment ([LiH3N]5−). Cationic double chains of edge‐shared [NSr5Li]8+ octahedra dominate the structure according to $^{1}_{\infty}\rm \{[N(Sr1)_{2/2}(Sr2)_{3/3}Li_{1/1}]^{2+}\}$. Running parallel to the [0 1 0] direction, they are bundled like a hexagonal rod‐packing which is interconnected by H− anions within the (0 0 1) plane first and finally even in the third dimension (i. e. along [0 0 1]). Therefore the structure of LiSr2H2N is compared to that one of the closely related quaternary hydride oxide LiLa2HO3.

Yellow to red, transparent single crystals of the lithium oxide chloride Li 5 OCl 3 were obtained as main product from a solid-state reaction between Li 3 N and oxygen-contaminated lithium (covered by a Li[OH] crust) with YbCl 3 and carbon in silica-jacketed, arc-welded niobium ampoules originally designed to yield Yb[CN 2 ]. Li 5 OCl 3 adopts the crystal structure of Cs 3 CoCl 5 (ϵ Cs 3 Cl[CoCl 4 ]) according to Cl 3 Li[OLi 4 ] with the tetragonal space group I4/mcm (no. 140) and the cell parameters a = 685.28(3) pm and c = 1093.23(5) pm for Z = 4. Hence, it contains isolated [OLi 4 ] 2+ tetrahedra in a LiCl matrix it thus