We have demonstrated the detection of the N-14 nuclear quadrupole resonance signal in an experimental setup, where the sample occupies the space between the capacitor plates instead of the coil as usual. The new technique may be useful fro the detection of the NQR signal from thin surface layers.
COBISS.SI-ID: 24453927
The quinolinol derivatives were studied experimentally in the solid state via 35Cl NQR, 1H-17O and 1H-14N NQDR spectroscopies, and theoretically by density functional theory (DFT). The results obtained in this work suggest that considerable differences in the NQR parameters for the planar and twisted supramolecular synthons permit differentiation between specific polymorphic forms, and indicate that the more planar supramolecular synthons are accompanied by a greater number of weaker hydrogen bonds linking them and stronger π•••π stacking interactions.
COBISS.SI-ID: 2337380
Nuclear quadrupole resonance is presented as a method for the study of solid hydrogen bonded materials. NQR study of hydrogen bonds in ferroelectric and paraelectric KH2PO4, antiferroelectric and paraelectric squaric acid, ferroelectric croconic acid and antiferroelectric and paraelectric cocrystal 5’-dimethyl-2,2’-bipyridine – chloranilic acid (1:1) are discussed in more details. A 14N NQR study of the strong short O-H…N hydrogen bond in two polymorphic forms of cocrystal isonicotinamide-oxalic acid (2:1) is presented as well. Various correlations between the NQR parameters and between the NQR and structural parameters have been observed. These correlations may be used to determine the proton position in a hydrogen bond and some other structural parameters from the NQR data.
COBISS.SI-ID: 2357092