Combined Effect of second-Order Quadrupole Coupling and Chemical Shielding Anisotropy on the Central Transition in MAS NMR of Quadrupolar Nuclei. ⁸⁷Rb MAS NMR of RbClO₄

TY - JOUR

T1 - Combined Effect of second-Order Quadrupole Coupling and Chemical Shielding Anisotropy on the Central Transition in MAS NMR of Quadrupolar Nuclei. 87Rb MAS NMR of RbClO4

AU - Vosegaard, Thomas

AU - Skibsted, Jørgen

AU - Bildsøe, Henrik

AU - Jakobsen, Hans J.

PY - 1995

Y1 - 1995

N2 - The combined effect of the tensorial interactions from both second-order quadrupole coupling and chemical shielding on the central transition in magic-angle spinning (MAS) NMR of half-integer quadrupolar nuclei has been convincingly observed and analyzed for the first time. 87Rb MAS NMR spectra of RbClO4 at 7.1, 9.4, and 11.7 T and at different spinning speeds serve as the illustrative example. The spectra are analyzed by iterative fitting of their complex line shapes using a modification of our simulation software recently described and employed for determination of the same two interactions from first-order MAS NMR spectra of all (central and satellite) transitions. Accurate and consistent values for the eight parameters describing the magnitudes and relative orientation of the two tensor interactions are obtained from the different spectra. The parameters determined from 87Rb MAS NMR are of higher accuracy than the values earlier reported from static-powder 87Rb NMR of RbClO4. The relative orientation (Euler angles ψ, χ, and ξ) determined for the two tensorial interactions conforms to the crystal structure for RbClO4 in an excellent manner.

AB - The combined effect of the tensorial interactions from both second-order quadrupole coupling and chemical shielding on the central transition in magic-angle spinning (MAS) NMR of half-integer quadrupolar nuclei has been convincingly observed and analyzed for the first time. 87Rb MAS NMR spectra of RbClO4 at 7.1, 9.4, and 11.7 T and at different spinning speeds serve as the illustrative example. The spectra are analyzed by iterative fitting of their complex line shapes using a modification of our simulation software recently described and employed for determination of the same two interactions from first-order MAS NMR spectra of all (central and satellite) transitions. Accurate and consistent values for the eight parameters describing the magnitudes and relative orientation of the two tensor interactions are obtained from the different spectra. The parameters determined from 87Rb MAS NMR are of higher accuracy than the values earlier reported from static-powder 87Rb NMR of RbClO4. The relative orientation (Euler angles ψ, χ, and ξ) determined for the two tensorial interactions conforms to the crystal structure for RbClO4 in an excellent manner.

U2 - 10.1021/j100027a009

DO - 10.1021/j100027a009

M3 - Journal article

AN - SCOPUS:0000415144

SN - 0022-3654

VL - 99

SP - 10731

EP - 10735

JO - Journal of Physical Chemistry

JF - Journal of Physical Chemistry

IS - 27

ER -