title: Hydrodynamic interpretation on the rotational diffusion of peroxylamine disulfonate solute dissolved in room temperature ionic liquids as studied by electron paramagnetic resonance spectroscopy.
abstract: Rotational motion of a nitroxide radical, peroxylamine disulfonate (PADS), dissolved in room temperature ionic liquids (RTILs) was studied by analyzing electron paramagnetic resonance spectra of PADS in various RTILs. We determined physical properties of PADS such as the hyperfine coupling constant (A), the temperature dependence of anisotropic rotational correlation times (τ(∥) and τ(⊥)), and rotational anisotropy (N). We observed that the A values remain unchanged for various RTILs, which indicates negligible interaction between the N-O PADS group and the cation of RTIL. Large N values suggest strong interaction of the negative sulfonyl parts of PADS with the cations of RTILs. Most of the τ(∥), τ(⊥), and (τ(∥)τ(⊥))(1/2) values are within the range calculated on the basis of a hydrodynamic theory with stick and slip boundary conditions. It was deduced that this theory could not adequately explain the measured results in some RTILs with smaller BF(4) and PF(6) anions.
authors.affiliation: Department of Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1 H57 Ohokayama, Meguro-ku, Tokyo 152-8551, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Miyake
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Akai
authors.forename: Akio
authors.initials: A
authors.lastname: Kawai
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Shibuya
mesh_terms: D000588:Amines / Q000737:chemistry*; D004058:Diffusion; D052578:Ionic Liquids / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010545:Peroxides / Q000737:chemistry*; D011789:Quantum Theory; D012399:Rotation; D012995:Solubility; D013696:Temperature
chemical_list: D000588:Amines; D052578:Ionic Liquids; D010545:Peroxides