Accession Number : AD0293441

Title :   NUCLEAR RELAXATION OF N-14 BY QUADRUPOLE INTERACTIONS IN MOLECULAR LIQUIDS

Corporate Author : ILLINOIS UNIV URBANA NOYES CHEMICAL LAB

Personal Author(s) : MONIZ,W.B. ; GUTOWSKY,H.S.

Report Date : 07 SEP 1962

Pagination or Media Count : 1

Abstract : RF pulse methods were used to measure the N-14 spin-lattice relaxation time in 25 molecular liquids, with the N-14 in several types of group. For eight of the compounds, microwave or pure quadrupole resonance measurements of the N-14 quadrupole coupling constant were combined with our T1 results to give values for the correlation time T/q describing the molecular reorientations which govern T1. These values for T/q at 25 C are about an order of agnitude shorter than reorientational correlation times calculated from the viscosity and molecular radius using the Debye-BPP approach. For the other compounds, T/q was estimated and used with the observed T1 for N-14 to predict values of the quadrupole coupling constant. The temperature dependence of T1 was observed for nine compounds, leading to activation energies for molecular reorientation of 1.4 to 3.2 kcal/mole and inverse frequency factors T/q of 2 to 9 times 10 to the -14th power sec. The temperature dependence of the proton T1 was observed in CH3CN and it is compared with that of N-14. (Author)

Descriptors :   *LIQUIDS, *NITROGEN, *NUCLEAR SPINS, *QUADRUPOLE MOMENT, *RELAXATION TIME, RADIOFREQUENCY PULSES

Distribution Statement : APPROVED FOR PUBLIC RELEASE