The Triply Deprotonated Acetonitrile Anion CCN3- Stabilized in a Solid

The {Re4} Tetrahedral Cyanometalate Cluster Anion [{Re4(μ3-CCN)4}(CN)12]8- with Inner (μ3-CCN)3- Ligands and Its Features in Coordination of Cu2+ Cations

A reaction between ReI₃ and KCN at elevated temperature led to the formation of the new cyanometalate cluster anion [{Re₄(μ₃-CCN)₄}(CN)₁₂]^8- (1). The anion contains μ₃-CCN^3- ligands, which are stabilized by the coordination to the triangular faces of the tetrahedral {Re₄} metallocluster in a μ₃ mode. The compound crystallized as a potassium salt, and its crystal structure was determined by single-crystal X-ray diffraction analysis. It was shown that μ₃-CCN^3- ligands are ambidentate and can interact with transition-metal cations similarly to terminal CN groups, resulting in the polymer framework formation.

The Quasi‐Binary Acetonitriletriide Sr 3 [C 2 N] 2

The first quasi‐binary acetonitriletriide Sr₃[C₂N]₂ has been synthesised and characterised. The nearly colourless crystals were obtained from the reaction of Sr metal, graphite, and elemental N₂, generated by decomposition of Sr(N₃)₂, in a sealed Ni ampoule with the aid of an alkali metal flux. The structure of this compound was analysed via single‐crystal X‐ray diffraction and the identity of the [C₂N]³⁻ anion was confirmed by Raman spectroscopy and further investigated by quantum‐chemical methods. Computed interatomic distances within the [C₂N]³⁻ anion strikingly match the obtained experimental data.

From oxide to a new type of molecular tungsten compound: formation of bitetrahedral cluster complexes [{W6(μ4-O)2(μ3-CCN)4}(CN)16]10- and [{W6(μ4-O)2(μ3-As)4}(CN)16]10

Tungsten trioxide has been found to be a convenient precursor for the synthesis of metal cluster compounds with new types of cluster cores. The reaction between WO3 and KCN led to the formation of the cluster complex [{W6(μ4-O)2(μ3-CCN)4}(CN)16]10-. Unexpectedly, it includes the fully deprotonated form of acetonitrile, the CCN3- anion, as a μ3-bridging ligand coordinated to the trigonal faces of the bitetrahedral W6 metallocluster. A similar complex [{W6(μ4-O)2(μ3-As)4}(CN)16]10- containing μ3-As3- ligands instead of μ3-CCN3- ones has been synthesized by the reaction between WO3, As and KCN.

Molecular Structure of Isocyanic Acid, HNCO, the Imide of Carbon Dioxide

Isocyanic acid, HNCO, the imide of carbon dioxide, was prepared by reaction of stearic acid and potassium cyanate (KOCN) at 60 °C in a sealed, thoroughly dried reactor. Interestingly, its crystal structure, solved by X-ray single crystal diffraction at 123(2) K, shows a group-subgroup relation for the NCO^- anion to carbon dioxide: (for CO₂, cP12, Pa3̅, a = 5.624(2) Å, 150 K, C-O 1.151(2) Å; for HNCO, oP16, Pca2₁, a = 5.6176(9), b = 5.6236(8), c = 5.6231(7) Å, 123(2) K). Precise positions of H, N, C, and O were determined by DFT calculations with WIEN2k leading to interatomic distances C-O 1.17, C-N 1.22, N-H 1.03, and -N-H···N 2.14 Å, and the interatomic angle N-C-O 171°.