title: Three cocrystals and a cocrystal salt of pyrimidin-2-amine and glutaric acid.
abstract: Four new cocrystals of pyrimidin-2-amine and propane-1,3-dicarboxylic (glutaric) acid were crystallized from three different solvents (acetonitrile, methanol and a 50:50 wt% mixture of methanol and chloroform) and their crystal structures determined. Two of the cocrystals, namely pyrimidin-2-amine-glutaric acid (1/1), C4H5N3·C6H8O4, (I) and (II), are polymorphs. The glutaric acid molecule in (I) has a linear conformation, whereas it is twisted in (II). The pyrimidin-2-amine-glutaric acid (2/1) cocrystal, 2C4H5N3·C6H8O4, (III), contains glutaric acid in its linear form. Cocrystal-salt bis(2-aminopyrimidinium) glutarate-glutaric acid (1/2), 2C4H6N3(+)·C6H6O4(2-)·2C6H8O4, (IV), was crystallized from the same solvent as cocrystal (II), supporting the idea of a cocrystal-salt continuum when both the neutral and ionic forms are present in appreciable concentrations in solution. The diversity of the packing motifs in (I)-(IV) is mainly caused by the conformational flexibility of glutaric acid, while the hydrogen-bond patterns show certain similarities in all four structures.
authors.affiliation: Department of Chemistry, Durham University, South Road, Durham DH1 3LE, England.
authors.forename: Isaac
authors.initials: I
authors.lastname: Odiase
authors.affiliation: Department of Chemistry, Durham University, South Road, Durham DH1 3LE, England.
authors.forename: Catherine E
authors.initials: CE
authors.lastname: Nicholson
authors.affiliation: Centre for Process Innovation, Wilton Centre, Wilton, Redcar TS10 4RF, England.
authors.forename: Ruksanna
authors.initials: R
authors.lastname: Ahmad
authors.affiliation: Centre for Process Innovation, Wilton Centre, Wilton, Redcar TS10 4RF, England.
authors.forename: Jerry
authors.initials: J
authors.lastname: Cooper
authors.affiliation: Department of Chemistry, Durham University, South Road, Durham DH1 3LE, England.
authors.forename: Dmitry S
authors.initials: DS
authors.lastname: Yufit
authors.affiliation: Department of Chemistry, Durham University, South Road, Durham DH1 3LE, England.
authors.forename: Sharon J
authors.initials: SJ
authors.lastname: Cooper
keywords: cocrystals; cocrystal–salt continuum; crystal engineering; crystal structure; glutaric acid; hydrogen bonds; polymorphs; pyrimidin-2-amine