K-39 nuclear magnetic resonance in a KHSO4 single crystal

The K-39 NMR in a KHSO4 single crystal grown by the slow evaporation method was investigated by employing a Bruker FT NMR spectrometer, and the K-39 q uadrupole coupling was determined from the angular dependences of the four K-39 +/- 1/2 <----> double dagger1/2 central NMR transitions. There are two sets of crystallographically inequivalent K+ ions: K(1) and K(2). From the se angular dependences, all lead to different values for the quadrupole cou pling constant and asymmetry parameter: e(2)qQ/h = 1.06 +/- 0.07 MHz, eta = 0.58 +/- 0.05 for the K(1) ion, and e(2)q Q/h = 1.45 +/- 0.07 MHz, eta = 0 .85 +/- 0.05 for the K(2) ion. The EFG tensors of K(1) rind K(2) are asymme tric sind the orientations of the principal axes of the EFG tensors do not coincide for the K(1) and K(2) sites. The K(1) ions surrounded by nine oxyg en atoms are high in symmetry while K(2) ions surrounded by nine oxygen ato ms show low symmetry.