Nuclear magnetic resonance of¹⁴N and³⁵Cl in ammonium perchlorate

Abstract

The nuclear quadrupole interaction tensor of 14N and 35CI and the diamagnetic shielding tensor of "CI in ammonium perchlorate at room temperature have been determined from nuclear magnetic resonance rotation studies of single crystals.

Solid-state NMR spectroscopy of the quadrupolar halogens: chlorine-35/37, bromine-79/81, and iodine-127

“…These spans are somewhat large relative to those reported previously for chloride 55 and oxychloro ions. 87,108 It is unclear whether the small quadrupolar interaction (e.g. C Q 35 Cl D 0.9 MHz for the room humidity sample) measured under MAS condition was taken into account when extracting the CS tensor components from the spectra of static samples.…”

14N and 39K Nuclear Quadrupole Coupüng in KNO3

“…This is in accordance with the site symmetry m already mentioned. Observed splittings have been fitted with sinusoidal functions by a method of extended least squares which we have used before [3], The method achieves accuracy by effectively giving greater weight to measurements near the turning-points. Owing to short-sighted programming, only about half the measurements of 39 K could be included in the fitting procedure.…”

“…The frequency separation between the transitions (m, m -1) and (1 -m, -m) can be described by the component in the laboratory frame (O xyz, O z || B) of a symmetric tensor v Q which is fixed in the crystal [3];…”

“…The quadrupole frequency tensor is transformed to a cartesian frame (with axes 1-3) in the crystal, coinciding with the respective crystal axes (a, b, c), in the manner of Volkoff [2,3]. The angular origin of each rotation has been adjusted slightly to conform with the point group symmetry, corresponding to Volkoff's case (1) adjustment [2].…”

“…The 39 K measurements were made, at the same temperatures, for two orientations 90° apart. In this case the quadrupole frequency tensor can be recovered with the aid of an adjustable angle; once again the point group symmetry is assumed [3]. Given the nominal setting co, the direction cosines of the magnetic field are allowed to have been mis-set, (3, z) = cos(co + e) in one orientation, (3, z) = sin (co -e) in the other, (l,z) = 0 in both.…”