Recording 2-D Nutation NQR Spectra by Random Sampling Method

The method of random sampling was introduced for the first time in the nutation nuclear quadrupole resonance (NQR) spectroscopy where the nutation spectra show characteristic singularities in the form of shoulders. The analytic formulae for complex two-dimensional (2-D) nutation NQR spectra (I = 3/2) were obtained and the condition for resolving the spectral singularities for small values of an asymmetry parameter η was determined. Our results show that the method of random sampling of a nutation interferogram allows significant reduction of time required to perform a 2-D nutation experiment and does not worsen the spectral resolution

Polarization and conformation effects in hydrogen-bonded complexes of trichloroacetic acid with various organic bases, studied by

The paper presents the results of analysis of 35Cl-NQR frequency measurements (at 77 K) for three resonance lines (ν1, v2 and ν3) ascribed to chlorine nuclei of the CCl2 group in trichloroacetic acid (TCA) complexes with various organic bases (B). The observed shifts in frequency of the resonance lines ν1, ν2 and ν3 versus ΔρΚa = ρKa (base) - ρKa (TCA) are compared with the frequency shifts calculated assuming the influence of electric dipole of hydrogen bond Οδ- H ... Βδ+ and of the dipoles of the groups Cδ+ = Oδ- and Cδ+ - Oδ- for the most probable conformation of CCl3 group in complexes studied