Study of the Halogen Bonding between Pyridine and Perfluoroalkyl Iodide in Solution Phase Using the Combination of FTIR and 19F NMR
| Autor: | Haiyan Fan-Hagenstein, Elizabeth Wood, Timothy W. Hanks, Briauna Hawthorne, Jessica M. Smith |
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| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
Halogen bond
Article Subject 010405 organic chemistry Intermolecular force Fluorine-19 NMR Halocarbon 010402 general chemistry Photochemistry 01 natural sciences 0104 chemical sciences Solvent lcsh:Chemistry chemistry.chemical_compound chemistry lcsh:QD1-999 Halogen Pyridine Molecule Physical chemistry lcsh:QC350-467 lcsh:Optics. Light |
| Zdroj: | International Journal of Spectroscopy, Vol 2013 (2013) |
| ISSN: | 1687-9449 |
| DOI: | 10.1155/2013/216518 |
| Popis: | Halogen bonding between pyridine and heptafluoro-2-iodopropane (iso-C3F7I)/heptafluoro-1-iodopropane (1-C3F7I) was studied using a combination of FTIR and19F NMR. The ring breathing vibration of pyridine underwent a blue shift upon the formation of halogen bonds with both iso-C3F7I and 1-C3F7I. The magnitudes of the shifts and the equilibrium constants for the halogen-bonded complex formation were found to depend not only on the structure of the halocarbon, but also on the solvent. The halogen bond also affected the Cα-F (C-F bond on the center carbon) bending and stretching vibrations in iso-C3F7I. These spectroscopic effects show some solvent dependence, but more importantly, they suggest the possibility of intermolecular halogen bonding among iso-C3F7I molecules. The systems were also examined by19F NMR in various solvents (cyclohexane, hexane, chloroform, acetone, and acetonitrile). NMR dilution experiments support the existence of the intermolecular self-halogen bonding in both iso-C3F7I and 1-C3F7I. The binding constants for the pyridine/perfluoroalkyl iodide halogen bonding complexes formed in various solvents were obtained through NMR titration experiments. Quantum chemical calculations were used to support the FTIR and19F NMR observations. |
| Databáze: | OpenAIRE |
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