An electron spin-echo envelope modulation study of 14N nuclear hyperfine and quadrupole coupling in copper(II)/nickel(II) bis N,N-di- n-butyl-dithiocarbamate)

Abstract

The electron spin-echo envelope modulation technique (ESEEM) is used to determine the 14N hyperfine and quadrupole tensors in copper-doped nickel(II) bis( N,N-di- n-butyl-dithiocarbamate). The line positions and peak intensities of the Fourier-transformed ESEEM spectra are interpreted using simulated spectra, obtained by diagonalizing the full spin-Hamiltonian matrix. The 14N quadrupole tensor can be accounted for theoretically by extended Hückel molecular orbital calculations. For the interpretation of the 14N hyperfine tensor, however, an unrestricted molecular orbital calculation is necessary. Therefore, one should be cautions in drawing conclusions about spin-density distributions from small hyperfine couplings of nuclei in higher coordination spheres.