Snap‐Shots of a Reduction Pathway: The Reaction of WCl 6 with Copper Powder

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.

Synthesis, Structure, and Electronic Properties of Sn9O5Cl4(CN2)2

The formation of the new compound Sn₉O₅Cl₄(CN₂)₂ is reported and placed in the context of several other recently discovered tin carbodiimide compounds (Sn(CN₂), Sn₂O(CN₂), and Sn₄Cl₂(CN₂)₃), all of which contain divalent tin. The crystal structure of Sn₉O₅Cl₄(CN₂)₂, as determined by X-ray powder diffraction, includes an unusual [Sn₈O₃] cluster, in which tin atoms form the motif of a hexagonal bipyramid. An additional tin atom and two oxygen atoms connect these clusters into chains. Mössbauer spectroscopy shows tin to predominantly adopt the +2 oxidation state, and electronic structure calculations predict Sn₉O₅Cl₄(CN₂)₂ to be a semiconductor.

Pandora's box of binary tungsten iodides

More than 20 binary tungsten iodides have been discovered. This was possible due to a new synthesis of W₃I₁₂ through halide exchange reaction and by thermal scanning. Depending on the I₂ partial pressure compounds can incorporate or release I₂. On heating they undergo self-reduction. Some tungsten iodide clusters can be directly transferred into solution.

A journey through ternary lead chlorido tungstates by thermal scanning

The reaction of WCl₆with lead powder affords six new compounds, all monitored in one DSC run, and characterized by XRD techniques.