A low-temperature redetermination of met­aldehyde

A low-temperature redetermination of met­aldehyde (systematic name: 2,4,6,8-tetra­methyl-1,3,5,7-tetroxocane), (CH₃-CHO)₄ or C₈H₁₆O₄, is reported, 69 years after the original determination [Pauling & Carpenter (1936). J. Am. Chem. Soc. 58, 1274-1278]. Met­aldehyde crystallizes in the space group I4. The asymmetric unit contains one quarter of a mol­ecule and the complete mol­ecule is generated by the fourfold rotation axis.

3,4-Dichloro-1-nitro­benzene–aniline (2/1)

The solvate structure of 3,4-dichloro-1-nitro­benzene with aniline, 2C₆H₃Cl₂NO₂·C₆H₇N, is reported. Ribbons of 3,4-dichloro­nitro­benzene, formed by Cl...Cl and N—O...Cl inter­actions, are linked together via N—H...O hydrogen bonds with aniline into an undulating two-dimensional sheet.

3,4-Dichloro-1-nitro­benzene–1,4-dioxane (4/1)

The solvate structure of 3,4-dichloro-1-nitro­benzene with 1,4-dioxane, C₆H₃Cl₂NO₂·0.25C₄H₈N₂, is reported. The asymmetric unit comprises two independent 3,4-dichloro-1-nitro­benzene mol­ecules and half of a 1,4-dioxane mol­ecule, the solvent molecule being disposed about a centre of inversion. Double chains of 3,4-dichloro-1-nitro­benzene are linked by Cl...Cl inter­actions and 1,4-dioxane mol­ecules via C—H...O hydrogen bonds into a two-dimensional sheet.