title: Structure of calcium 2,6-difluorobenzoate dihydrate.
abstract: Ca2+.2C7H3O2F2-.2H2O, M(r) = 390.3, monoclinic, C2/c, a = 17.584 (4), b = 10.771 (3), c = 7.887 (2) A, beta = 91.28 (2) degrees, V = 1493 A3, Z = 4, Dm = 1.75, Dx = 1.74 g cm-3, lambda(Mo K alpha) = 0.71073 A, mu = 4.92 cm-1, F(000) = 792, T = 293 K, final R = 0.037 for 2415 unique observed reflections. The eight-coordinate Ca2+ ion is linked to six carboxylate O atoms from four different 2,6-difluorobenzoate ions and two water molecules. Each 2,6-difluorobenzoate ion chelates one Ca2+ ion and forms unidentate bridging linkages to two other Ca2+ ions leading to a polymeric structure. Unlike the situation in calcium 2-fluorobenzoate, the two F atoms in this structure are not involved in significant C-F...H-O hydrogen bonding.
authors.affiliation: Department of Chemistry, Miami University, Oxford, Ohio 45056.
authors.forename: A
authors.initials: A
authors.lastname: Karipides
authors.forename: C
authors.initials: C
authors.lastname: White
authors.forename: K
authors.initials: K
authors.lastname: Peiffer
mesh_terms: D001565:Benzoates / Q000737:chemistry*; D008958:Models, Molecular; D014961:X-Ray Diffraction
chemical_list: D001565:Benzoates; C077004:2,6-difluorobenzoic acid