title: Supramolecular structures of 5-[3-(4-methylphenyl)- and 5-[3-(4-chlorophenyl)-2-propenylidene]-2,2-dimethyl-1,3-dioxane-4,6-dione.
abstract: 2,2-dimethyl-5-[3-(4-methylphenyl)-2-propenylidene]-1,3-dioxane-4,6-dione, C16H16O4, crystallizes in the triclinic space group P-1, with two molecules in the asymmetric unit. These molecules and a centrosymmetrically related pair, linked together by weak C-H...O hydrogen bonds, form a tetramer. 5-[3-(4-Chlorophenyl)-2-propenylidene]-2,2-dimethyl-1,3-dioxane-4,6-dione, C15H13ClO4, also crystallizes in the triclinic space group P-1, with one molecule in the asymmetric unit. Centrosymmetrically related molecules are linked together by weak C-H...O hydrogen bonds to form dimers which are further linked by yet another pair of centrosymmetrically related C-H...O hydrogen bonds to form a tube which runs parallel to the a axis.
authors.affiliation: Department of Chemistry, University of Aberdeen, Meston Walk, Old Aberdeen AB24 3UE, Scotland. jnlow111@hotmail.com
authors.forename: John Nicolson
authors.initials: JN
authors.lastname: Low
authors.forename: Justo
authors.initials: J
authors.lastname: Cobo
authors.forename: Manuel
authors.initials: M
authors.lastname: Nogueras
authors.forename: Adolfo
authors.initials: A
authors.lastname: Sánchez
authors.forename: Braulio
authors.initials: B
authors.lastname: Insuasty
authors.forename: Harlen
authors.initials: H
authors.lastname: Torres