Accession Number : AD0607770

Title :   ANISOTROPY OF THE CHEMICAL SHIFT OF TRAPPED CHF3 AND NF3.

Descriptive Note : Technical rept. no. 4,

Corporate Author : DUKE UNIV DURHAM N C

Personal Author(s) : Harris,A. Brooks ; Hunt,Earle ; Meyer,Horst

Report Date : 10 OCT 1964

Pagination or Media Count : 50

Abstract : A study was made of the F19 chemical shift anisotropy in NF3 and CHF3 trapped in beta-quinol clathrates. The nuclear magnetic resonance was observed at several frequencies with the magnetic field applied at various angles relative to the crystal axis. The orientation of the molecules in the cavity and the dipolar broadening due to the lattice protons could be estimated rather closely by a qualitative analysis of the line shapes. The principal components of the chemical shift tensor of NF3 could be determined from the observed variation of the first and second moments of the line with the strength and orientation of the magnetic field. This determination was further substantiated by the good agreement between the calculated and observed line shapes for various values of the magnetic field. For CHF3, where the chemical shift anisotropy is smaller, only a cruder analysis was practicable. The sign and order of magnitude of the chemical shift anisotropy are discussed and can be understood on the basis of current ideas about the relationship between the bond characters and the chemical shift anisotropy. (Author)

Descriptors :   (*NITROGEN COMPOUNDS, FLUORIDES), (*FLUORIDES, ANISOTROPY), (*HALOGENATED HYDROCARBONS, ANISOTROPY), COMPLEX COMPOUNDS, CRYSTAL LATTICES, PROTONS, NUCLEAR MAGNETIC RESONANCE, LINE SPECTRA, CHEMICAL BONDS, NUCLEAR SPINS

Distribution Statement : APPROVED FOR PUBLIC RELEASE