Off-resonance effects on 2D NMR nutation spectra of I = 3 2 quadrupolar nuclei in static samples

The off-resonance effects on 2D NMR nutation of I = 3 2 quadrupolar nuclei are demonstrated with perturbation theory and numerical calculation in static samples. The off-resonant (Δω) rf field (ω₁) enlarges a nutation frequency and consequently increases the measurement range of nuclear quadrupolar interaction parameters. When ω_e > ω_Q^max, and arctg( ω₁ Δω) = ±54.7 ° (magic angle), the satellite lines (produced by coherence transfers) in a nutation spectrum are superimposed with the line of central transition, and hence the nutation spectrum is simplified and its sensitivity is enhanced. The nuclear quadrupolar interaction parameters of ²³Na nuclei in NaΩ molecular sieve are obtained using 2D NMR nutation.