2D Ligand ENDOR and TRIPLE resonance studies of Cu(II)-doped DTGS single crystals

Abstract

The deuteron hyperfine and quadrupole coupling tensors in the bis(glycinato)-Cu(II) ((ND2CH2COO)2Cu) complex in ferroelectric triglycine sulfate (DTGS) single crystals were measured by ENDOR spectroscopy. These data indicate that the molecular symmetry of the Cu complex is C1. From TRIPLE resonance experiments the signs of the isotropic coupling constants were determined. Structural information was obtained from the principal values of the quadrupole coupling tensors of the deuterium atoms and their direction cosines. Using the relationship between the deuterium quadrupole constant and ND bond lengths, the positions of the deuterons in bis(glycinato)-Cu(II) were estimated. The negative signs of the isotropic hyperfine coupling constants were explained by spin polarization of the deuteron 1s orbitals. The values of the anisotropic hyperfine coupling constants are discussed in the framework of conventional molecular-orbital theory and can be understood quite satisfactorily.