title: Pseudopolymorphism in hydroxybenzophenones: the dihydrate of 2,2',4,4'-tetrahydroxybenzophenone.
abstract: A dihydrate pseudopolymorph of bis(2,4-dihydroxyphenyl)methanone, C(13)H(10)O(5)·2H(2)O, (I), was obtained during polymorphism screening of hydroxybenzophenone derivatives. This structure, in which the molecule sits on a twofold axis, was compared with the known anhydrous form of (I) [Schlemper (1982). Acta Cryst. B38, 554-559]. The role of water in the crystal assembly was established on the basis of the known monohydrate pseudopolymorph of 3,4-dihydroxybenzophenone [Landre, Souza, Corrêa, Martins & Doriguetto (2010). Acta Cryst. C66, o463-o465].
authors.affiliation: Laboratório de Cristalografia, Instituto de Química, Universidade Federal de Alfenas, Alfenas, Brazil.
authors.forename: I M R
authors.initials: IM
authors.lastname: Landre
authors.forename: F T
authors.initials: FT
authors.lastname: Martins
authors.forename: J A
authors.initials: JA
authors.lastname: Ellena
authors.forename: M H
authors.initials: MH
authors.lastname: Dos Santos
authors.forename: A C
authors.initials: AC
authors.lastname: Doriguetto
mesh_terms: D001577:Benzophenones / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D015394:Molecular Structure; D014867:Water / Q000737:chemistry*
chemical_list: C552505:3,4-dihydroxybenzophenone; D001577:Benzophenones; D014867:Water