title: A pseudo-quadruple hydrogen-bonding motif consisting of six N-H...O hydrogen bonds in trimethoprim formate.
abstract: The title compound, trimethoprim (TMP) formate [systematic name: 2,4-diamino-5-(3,4,5-trimethoxybenzyl)pyrimidin-1-ium formate], C(14)H(19)N(4)O(3)(+).CHO(2)(-), reveals a pseudo-quadruple hydrogen-bonding motif consisting of six N-H.O hydrogen bonds involving two unpaired TMP cations and two formate anions which are symmetrically disposed. The hydrogen-bonding motif is strikingly comparable with that observed in other TMP salts where the aminopyrimidine moieties of the TMP cations are centrosymmetrically paired. These conserved hydrogen-bonding motifs may serve as robust synthons in crystal engineering and design. The characteristic pseudo-quadruple hydrogen-bonding motif and other intermolecular hydrogen bonds operating in the crystal form a two-dimensional supramolecular sheet structure.
authors.affiliation: Department of Chemistry, Bharathidasan University, Tiruchirapalli 620 024, India.
authors.forename: Balakrishnan
authors.initials: B
authors.lastname: Umadevi
authors.forename: Ponraj
authors.initials: P
authors.lastname: Prabakaran
authors.forename: Packianathan Thomas
authors.initials: PT
authors.lastname: Muthiah
mesh_terms: D018360:Crystallography, X-Ray; D005493:Folic Acid Antagonists / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D014295:Trimethoprim / Q000737:chemistry*
chemical_list: D005493:Folic Acid Antagonists; D014295:Trimethoprim