Diisothio­cyanato­tetra­kis­(1-meth­yl-1H-imidazole-κN³)nickel(II)

The structure of the title compound, [Ni(NCS)₂(C₄H₆N₂)₄], consists of isolated mol­ecules of [Ni(NCS)₂(Mim)₄] (Mim = 1-methyl­imidazole), which contain a compressed octa­hedral NiN₆ chromophore. The NCS⁻ anions are trans and four N atoms from the 1-methyl­imidazole ligands define the equatorial plane. The mean Ni—N(Mim) and Ni—N(NCS) distances are 2.115 (4) and 2.087 (4) Å, respectively.

Redetermination of 3-[(Z)-1-hydr­oxy-3-oxobuten­yl]-2H-chromen-2-one at 193 K

The structure of the title compound, C₁₃H₁₀O₄, which was synthesized by the reaction of salicylaldehyde and 4-hydr­oxy-6-meth­yl-2H-pyran-2-one in the presence of triethyl­benzyl­ammonium chloride in aqueous media, was previously determined at room temperature [March, Moreno-Manas, Roca, Germain, Piniella & Dideberg (1986). J. Heterocycl. Chem. 23, 1511–1153]. As in the present determination, the X-ray analysis revealed that the title compound is in the enol form, which was confirmed by ¹H NMR data. Weak inter­molecular C—H...O inter­actions connect mol­ecules into a two-dimensional framework.