The new carbonyl nickelate salt [A([18]crown‐6)]2[Ni(CO)3]·8NH3 (A = K, Rb) serendipitously crystallized from a solution of (PPh3)2Ni(CO)2, [18]crown‐6, [2.2.2]cryptand, and K6Rb6Ge17 in liquid ammonia. The [Ni(CO)3]2– anion represents the first tricarbonyl compound of nickel characterized by X‐ray diffraction studies and completes the row of known carbonyl metalates. The planar anion displays approximately D3h symmetry. The calculated electron localization function (ELF) of the complex shows plane basins above and below the molecular plane and the twofold negative charge is spread over the Ni(CO)3 entity.

Abstract. The new compound [Rb([18]

The reactions between K 5 Bi 4 , [(C 6 H 6 )Cr(CO) 3 ] or [(C 7 H 8 )Mo(CO) 3 ], and [2.2.2]crypt in liquid ammonia yielded the compounds [K([2.2.2]crypt)] 3 (η 3 -Bi 3 )M(CO) 3 ·10NH 3 (M = Cr, Mo), which crystallize isostructurally in P2 1 /n. Both contain an 18 valence electron piano-stool complex with a η 3 -coordinated Bi 3 -ring ligand.

Abstract. The reaction of Cs 3 As 7 with diphenylacetylene in the presence of [18]crown-6 in liquid ammonia results in the formation of the new compound [Cs([18]crown-6)] 2 As 7 C 14 H 11 ·6NH 3 , which crystallizes in black monoclinic crystals. It contains the first monosubstituated heptaarsenide anion with a hydrocarbon-only substituent and theoretical calculations show a significant influence of the organic substituent on the electronic structure within the cage. The (Z)-1,2-diphen-

The cover picture shows the molecular structure of the mononuclear tricarbonyl nickelate [Ni(CO)3]2– synthesized by dissolving a Zintl phase, a nickel complex and chelating agents in liquid ammonia. The planar anion evinces almost perfect D3h symmetry. The calculated isosurface of the electron localization function (ELF) shows plane basins above and below the molecular plane, where the electrons of the twofold negative charge are evenly distributed. More details are discussed in the paper by Korber et al. on page http://onlinelibrary.wiley.com/doi/10.1002/zaac.201800111/abstract.