The existence of a strong spatial localization for the efficiency of cross-polarization by single quantum transition in the presence of a main field gradient was evidenced . The case of the solids with strong dipolar interactions has been analyzed. The slice profile of the transferred polarization was evaluated for different cross-polarization procedures. The spatial localization is superior as compared with the spin-locking slice selection method.
The NMR response of an isolated spin-3/2 system with an axially symmetric quadrupolar interaction under magic-angle sample spinning to an ideal radio-frequency pulse using irreducible tensor operators is evaluated analytically. The excited single-quantum spin coherences are modulated by the sample spinning. The effects of spinning frequency, quadrupole coupling constant and the orientation of quadrupolar interaction relative to rotor axis on the spinning-side-band patterns are simulated. High-resolution single-quantum spinning-side-band pattern detected for ^{23}Na (I=3/2) nuclei in sodium nitrate powder is compared with the simulation based on the theory and the quadrupole coupling is estimated.
The possibility to perform homonuclear separated-local field NMR spectroscopy by magnetization-exchange is presented. Solid-state one-dimensional proton magnetization-exchange NMR is used to investigate intergroup residual dipolar couplings in cis-1,4-polybutadiene elastomer. A three-spin model is employed, in which the CH- and CH_{2}-protons are considered to be coupled by residual dipolar interactions. The magnetization-exchange process between the CH- and the CH_{2}-group in the regime of short mixing time provides valuable insight regarding molecular order. The spin-system response reflects well-localized dipolar interactions. The residual intergroup dipolar couplings are measured along the average polymer-chain direction for different temperatures. The dynamic order parameter along the chains is also evaluated.
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