title: Halogen bonding in iodo-perfluoroalkane/pyridine mixtures.
abstract: Mole fraction and temperature studies of halogen bonding between 1-iodo-perfluorobutane, 1-iodo-perfluorohexane, or 2-iodo-perfluoropropane and pyridine were performed using noisy light-based coherent anti-Stokes Raman scattering (I((2)) CARS) spectroscopy. The ring breathing mode of pyridine both is highly sensitive to halogen bonding and provides a strong I((2)) CARS signal. As the lone pair electrons from the pyridinyl nitrogen interact with the sigma-hole on the iodine from the iodo-perfluoroalkane, the ring breathing mode of pyridine blue-shifts proportionately with the strength of the interaction. The measured blue shift for halogen bonding of pyridine and all three iodo-perfluoroalkanes is comparable to that for hydrogen bonding between pyridine and water. 2-Iodo-perfluoropropane displays thermodynamic behavior that is different from that of the 1-iodo-perfluoroalkanes, which suggests a fundamental difference at the molecular level. A potential explanation of this difference is offered and discussed.
authors: Department of Chemistry, Concordia College, Moorhead, Minnesota 56562, USA.
authors: Haiyan
authors: H
authors: Fan
authors: Jeffrey K
authors: JK
authors: Eliason
authors: C Diane
authors: CD
authors: Moliva A
authors: Jason L
authors: JL
authors: Olson
authors: Scott M
authors: SM
authors: Flancher
authors: M W
authors: MW
authors: Gealy
authors: Darin J
authors: DJ
authors: Ulness