title: Hydrogen-bonded frameworks of bis(2-carboxypyridinium) hexafluorosilicate and bis(2-carboxyquinolinium) hexafluorosilicate dihydrate.
abstract: In bis(2-carboxypyridinium) hexafluorosilicate, 2C(6)H(6)NO(2)+.SiF6(2-), (I), and bis(2-carboxyquinolinium) hexafluorosilicate dihydrate, 2C(10)H(8)NO(2)+.SiF6(2-).2H2O, (II), the Si atoms of the anions reside on crystallographic centres of inversion. Primary inter-ion interactions in (I) occur via strong N-H...F and O-H...F hydrogen bonds, generating corrugated layers incorporating [SiF6](2-) anions as four-connected net nodes and organic cations as simple links in between. In (II), a set of strong N-H...F, O-H...O and O-H...F hydrogen bonds, involving water molecules, gives a three-dimensional heterocoordinated rutile-like framework that integrates [SiF6](2-) anions as six-connected and water molecules as three-connected nodes. The carboxyl groups of the cation are hydrogen bonded to the water molecule [O...O = 2.5533 (13) A], while the N-H group supports direct bonding to the anion [N...F = 2.7061 (12) A].
authors.affiliation: Physico-Chemical Instutute of Environmental and Human Protection, Ministry of Education and Science of Ukraine and National Academy of Sciences of Ukraine, Preobrazhens'ka Street 3, Odessa 65082, Ukraine.
authors.forename: Vladimir O
authors.initials: VO
authors.lastname: Gelmboldt
authors.forename: Eduard V
authors.initials: EV
authors.lastname: Ganin
authors.forename: Konstantin V
authors.initials: KV
authors.lastname: Domasevitch
mesh_terms: D002412:Cations / Q000737:chemistry; D018360:Crystallography, X-Ray; D005459:Fluorides / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008968:Molecular Conformation; D010848:Picolinic Acids / Q000737:chemistry*; D011726:Pyridinium Compounds / Q000737:chemistry*; D011804:Quinolines / Q000737:chemistry*; D011806:Quinolinium Compounds / Q000737:chemistry*; D012824:Silicic Acid / Q000737:chemistry*
chemical_list: D002412:Cations; D010848:Picolinic Acids; D011726:Pyridinium Compounds; D011804:Quinolines; D011806:Quinolinium Compounds; D012824:Silicic Acid; C004832:hexafluorosilicate; C008898:quinaldic acid; D005459:Fluorides