Solid State Complex Chemistry: Formation, Structure, and Properties of Homoleptic Tetracyanamidogermanates RbRE[Ge(CN2)4] (RE = La, Pr, Nd, Gd)

The luminescent semiconductor Pb7I6(CN2)4

The development of new compounds in the domain of metal dinitridocarbonates is most efficiently performed via solid-state metathesis or simply by addition reactions. Our discovery of Pb7I6(CN2)4 is the result of a solid-state reaction of PbCN2 with PbI2 at 420 °C. Its crystal structure was solved and refined from X-ray diffraction data based on a single crystal with the space group P63/mmc. The crystal structure is based on a network of lead tetrahedra, lead trigonal bipyramids and lead octahedra interconnected by [NCN]2- and iodide. Properties of the material were investigated by diffuse reflection measurement, photoluminescence measurements, and electronic band structure calculations demonstrating that this material is a semiconductor.

Carbodiimide Bridged Network Structure of [RE6O(NCN)6] Clusters in the Structure of RE8O(CN2)10Br2, RE = La, Ce, Pr, Nd

New rare earth (RE) carbodiimides having the formula RE8O(CN2)10Br2 were synthesized by solid-state metathesis reactions. Structure determinations and refinements, based on single-crystal X-ray diffraction data, are performed with the space group P͞3c1. Homologous compounds with RE = La, Ce, Pr, and Nd are assigned isotypically. The refined crystal structure appears most unusual for rare earth carbodiimide compounds. The structure is characterized by the formally neutral [RE6O(NCN)8] fragment that is tightly interconnected by carbodiimide ions into a network structure, and contains additional RE3+ ions in the structure. Crystals of the compounds show characteristic colors of their corresponding RE3+ ions and behave stable in air. The presence of (CN2)2− ions was confirmed by infrared spectroscopy. Ce8O(CN2)10Br2 is a photoluminescent material that is showing a broad and efficient emission band in the yellow region of the visible spectrum.

Recent progress in solid-state nuclear magnetic resonance of half-integer spin low-γ quadrupolar nuclei applied to inorganic materials

An overview is presented of recent progress in the solid-state nuclear magnetic resonance (NMR) observation of low-γ nuclei, with a focus on applications to inorganic materials. The technological and methodological advances in the last 20 years, which have underpinned the increased accessibility of low-γ nuclei for study by solid-state NMR techniques, are summarised, including improvements in hardware, pulse sequences and associated computational methods (e.g., first principles calculations and spectral simulation). Some of the key initial observations from inorganic materials of these nuclei are highlighted along with some recent (most within the last 10 years) illustrations of their application to such materials. A summary of other recent reviews of the study of low-γ nuclei by solid-state NMR is provided so that a comprehensive understanding of what has been achieved to date is available.

Synthesis, Structure, and Electronic Properties of Sn(CN2) and Sn4Cl2(CN2)3

A solid-state metathesis reaction between equimolar amounts of Li₂(CN₂) and SnCl₂ revealed the formation of two new compounds, Sn₄Cl₂(CN₂)₃ and Sn(CN₂). Thermal analysis of this reaction indicated that Sn₄Cl₂(CN₂)₃ forms exothermically near 200 °C and subsequently transforms into Sn(CN₂) at higher temperatures. The crystal structures of both compounds are presented. According to optical measurements and band structure calculations, Sn(CN₂) can be considered as a semiconductor with a band gap on the order of 2 eV. The presence of Sn²⁺ ions in the structure of Sn(CN₂) with a toroidally shaped lone pair is indicated by electron localization function calculations. The structure of Sn(CN₂) is shown to be related to the structures of FeS₂ and CaC₂.

Chloride carbodiimide K12Pb51(CN2)30Cl54 with an unprecedented 45 Å unit cell axis and a large birefringence

K₁₂Pb₅₁(CN₂)₃₀Cl₅₄ exhibits a giant birefringence of 0.094 at 1064 nm and a large cell axis due to the rotation of Pb²⁺ cations.

Recent advances in solid-state nuclear magnetic resonance spectroscopy of exotic nuclei

We present a review of recent advances in solid-state nuclear magnetic resonance (SSNMR) studies of exotic nuclei. Exotic nuclei may be spin-1/2 or quadrupolar, and typically have low gyromagnetic ratios, low natural abundances, large quadrupole moments (when I > 1/2), or some combination of these properties, generally resulting in low receptivities and/or prohibitively broad line widths. Some nuclides are little studied for other reasons, also rendering them somewhat exotic. We first discuss some of the recent progress in pulse sequences and hardware development which continues to enable researchers to study new kinds of materials as well as previously unfeasible nuclei. This is followed by a survey of applications to a wide range of exotic nuclei (including e.g., ⁹Be, ²⁵Mg, ³³S, ³⁹K, ⁴³Ca, ^47/49Ti, ⁵³Cr, ⁵⁹Co, ⁶¹Ni, ⁶⁷Zn, ⁷³Ge, ⁷⁵As, ⁸⁷Sr, ¹¹⁵In, ¹¹⁹Sn, ^121/123Sb, ^135/137Ba, ^185/187Re, ²⁰⁹Bi), most of them quadrupolar. The scope of the review is the past ten years, i.e., 2007-2017.

Synthesis and thermoelastic properties of Zr(CN2)2and Hf(CN2)2

Metal carbodiimides with wine-rack topology exhibiting thermoelastic properties like those of flexible framework materials.

Tin(ii) oxide carbodiimide and its relationship to SnO

Sn₂O(CN₂) was obtained from a solid-state metathesis. Its crystal structure incorporates a Sn²⁺ ion with a 5s² lone pair and was analyzed in relation to that of SnO by electronicstructure calculations and a COHP bonding analysis.