title: pi-Stacked dimers in 6-methoxy-3,3-dimethyl-3H-benzo[f]chromene, and centrosymmetric dimers containing C-H...pi(arene) hydrogen bonds in racemic 3-bromo-2,2,6,6-tetramethyl-3,4-dihydro-2H,6H-1,5-dioxatriphenylene.
abstract: The title compounds, namely 6-methoxy-3,3-dimethyl-3H-benzo[f]chromene, C(16)H(16)O(2), (III), and racemic 3-bromo-2,2,6,6-tetramethyl-3,4-dihydro-2H,6H-1,5-dioxatriphenylene, C(20)H(21)BrO(2), (IV), were both synthesized in one-step regioselective Wittig reactions from substituted 1,2-naphthoquinones. The new ring in both compounds adopts a screw-boat conformation. A single pi-pi stacking interaction links the molecules of (III) into centrosymmetric dimeric aggregates, and a single C-H...pi(arene) hydrogen bond links the molecules of (IV) into centrosymmetric dimers.
authors.affiliation: Universidade Federal Fluminense, Instituto de Química, Departamento de Química Orgânica-PQO, 24020-150 Niterói, Rio de Janeiro, RJ, Brazil.
authors.forename: Fernando de C
authors.initials: Fde C
authors.lastname: da Silva
authors.forename: James L
authors.initials: JL
authors.lastname: Wardell
authors.forename: Solange M S V
authors.initials: SM
authors.lastname: Wardell
authors.forename: Vitor F
authors.initials: VF
authors.lastname: Ferreira
authors.forename: John N
authors.initials: JN
authors.lastname: Low
authors.forename: Christopher
authors.initials: C
authors.lastname: Glidewell
mesh_terms: D001578:Benzopyrans / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D018360:Crystallography, X-Ray; D019281:Dimerization; D006576:Heterocyclic Compounds, 4 or More Rings / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: C525542:3-bromo-2,2,6,6-tetramethyl-3,4-dihydro-2H,6H-1,5-dioxatriphenylene; C525543:6-methoxy-3,3-dimethyl-3H-benzo(f)chromene; D001578:Benzopyrans; D006576:Heterocyclic Compounds, 4 or More Rings; D002244:Carbon; D006859:Hydrogen