title: 35Cl NOR and 19F NMR relaxation studies of CClF2 group dynamics in N(CH3)4H(ClF2CCOO)2.
abstract: The reorientation of CClF2 groups in N(CH3)4H(ClF2CCOO)2 has been studied using pulsed NQR and NMR techniques. The temperature dependence of both chlorine (35Cl) NQR and fluorine (19F) NMR spin-lattice relaxation has been measured T1Q of chlorine is attributed to the sum of two contributions: the reorientation of CClF2 groups and the modulation of the electric field gradient (EFG) produced by the motion of the N(CH3)4+ cations. The activation energies were determined for both kinds of motion. The fluorine relaxation is dominated by an intramolecular 19F-1H dipolar interaction. In analysis of cross-relaxation effects the spectral density functions have been evaluated using the motional parameters obtained from NQR data.
authors.affiliation: Institute of Molecular Physics, Polish Academy of Sciences, Poznań, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Zdanowska-Fraczek
authors.forename: W
authors.initials: W
authors.lastname: Medycki
mesh_terms: D000085:Acetates / Q000737:chemistry*; D002713:Chlorine / Q000737:chemistry; D003460:Crystallization; D005461:Fluorine / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D000085:Acetates; D000644:Quaternary Ammonium Compounds; D005461:Fluorine; D002713:Chlorine; C072794:chlorodifluoroacetic acid; C027917:tetramethylammonium