35Cl NQR and 19F NMR relaxation studies of CClF2 group dynamics in N(CH3)4H(ClF2CCOO)2

✍ Scribed by M. Zdanowska-Fra̧czek; W. Medycki

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 445 KB
• Volume: 6
• Category: Article
• ISSN: 0926-2040
• DOI: 10.1016/0926-2040(95)01216-8

✦ Synopsis

The reorientation of CClF, groups in N(CH,),H(ClF,CCOO), has been studied using pulsed NQR and NMR techniques. The temperature dependence of both chlorine ("'Cl) NQR and fluorine ('"F) NMR spin-lattice relaxation has been measured T,, of chlorine is attributed to the sum of two contributions: the reorientation of CCIF, groups and the modulation of the electric field gradient (EFG) produced by the motion of the N(CH,)i cations. The activation energies were determined for both kinds of motion.

The fluorine relaxation is dominated by an intramolecular '"F-'H dipolar interaction. In analysis of cross-relaxation effects the spectral density functions have been evaluated using the motional parameters obtained from NQR data.