21 research outputs found
Molecular structure of 8-hydroxy-1-methylquinolinium iodide hydrate in crystal and solution
8-Hydroxy-1-methylquinolinium iodide monohydrate [(C10H10NO)I-+(-) H2O] has been studied by X-ray diffraction, FF-IR, H-1 and C-13 NMR spectroscopy. In the crystalline state, the iodide anion is hydrogen-bonded to the water molecule, which in turn is hydrogen bonded to the 8-OH group of the 8-hydroxyquinolinium ring, forming of a symmetric dimer. In acetonitrile and DMSO-d(6) the hydrate assumes a new structure due to almost complete dissociation of the water molecule from the complex structure. In acetonitrile the 8-OH group is hydrogen-bonded to the iodide anion, whereas in DMSO-d(6) it forms the hydrogen bond with the solvent molecules. This 8-OH... O(DMSO-d(6)) hydrogen bond is the strongest within the structure of the hydrate
Molecular structure of 8-hydroxy-1-methylquinolinium iodide hydrate in crystal and solution
8-Hydroxy-1-methylquinolinium iodide monohydrate [(C10H10NO)I-+(-) H2O] has been studied by X-ray diffraction, FF-IR, H-1 and C-13 NMR spectroscopy. In the crystalline state, the iodide anion is hydrogen-bonded to the water molecule, which in turn is hydrogen bonded to the 8-OH group of the 8-hydroxyquinolinium ring, forming of a symmetric dimer. In acetonitrile and DMSO-d(6) the hydrate assumes a new structure due to almost complete dissociation of the water molecule from the complex structure. In acetonitrile the 8-OH group is hydrogen-bonded to the iodide anion, whereas in DMSO-d(6) it forms the hydrogen bond with the solvent molecules. This 8-OH... O(DMSO-d(6)) hydrogen bond is the strongest within the structure of the hydrate
Systematics in NH<sup>+</sup>···N-Bonded Monosalts of 4,4′-Bipyridine (44′biPy) with Mineral Acids
Despite
significantly different crystal symmetry and packing, the
crystal structures of NH<sup>+</sup>···N hydrogen-bonded
salts of 4,4′-bipyridine (44′biPy) with mineral acids
H<i>A</i> = HCl, HBr, HI, HClO<sub>4</sub>, HBF<sub>4</sub> and H<sub>2</sub>SiF<sub>6</sub> exhibit close analogies in the
hydration, aggregation of the cations and their twisted conformation,
as well as proton disordering. All monosalts have been synthesized
and, at normal conditions, form crystals of general formula [44′biPyH]<sup>+</sup><i>A</i><sup><i>–</i></sup>·<i>x</i>H<sub>2</sub>O (<i>x</i> = 0.5, 1, or 2), and
[44′biPyH]<sup>+</sup><sub>2</sub>SiF<sub>6</sub><sup>2–</sup>·5H<sub>2</sub>O. In the structures, the 44′biPyH<sup>+</sup> cations are NH<sup>+</sup>···N bonded into
linear chains, and in most [44′biPyH]<sup>+</sup><i>A</i><sup><i>–</i></sup>·<i>x</i>H<sub>2</sub>O crystals the protons are disordered, similarly as in anisotropic
relaxors 1,4-diazabicyclo[2.2.2]octane hydroiodide and hydrobromide
(dabcoHI and dabcoHBr, respectively). The proton disorder implies
generation of point defects of neutral 44′biPy molecules and
[44′biPyH<sub>2</sub>]<sup>2+</sup> dications in all these
structures. In all [44′biPyH]<sup>+</sup><i>A</i><sup><i>–</i></sup> structures investigated, the
acid anions are hydrogen bonded to water molecules and interact with
pyridine hydrogen atoms. Two polymorphs of [44′biPyH]<sup>+</sup>I<sup>–</sup>·H<sub>2</sub>O differ in color: the orthorhombic
polymorph α is yellow, and the triclinic polymorph β is
orange