Factors Affecting: the Line-width of Nitrogen Superhyperfine Structure in the ESR Spectra of Copper(II) Complexes

Abstract

Abstract ESR spectra were measured for several series of copper(II) complexes in an attempt to find the best-observable condition for 14N-superhyperfine structure. It was demonstrated that in addition to the temperature and the dilution factors the line-width of 14N-superhyperfine structure is broadened out by the following factors; 1) deviation from square planar configuration around a copper ion, i. e., deformation to elongated octahedron or square pyramid due to weak bonding along the tetragonal axis and/or distortion of coplanality of the coordination bond effected by some steric condition, and 2) the presence of protons that can couple with an unpaired electron and 14N-nuclei.