Paramagnetic Resonance of Copper Complex Salts

A paramagnetic resonance experiment was performed on Cu${\left(\mathrm{N}{\mathrm{H}}_3\right)}_4$S${\mathrm{O}}_4$·${\mathrm{H}}_2$O and Cu${\left(\mathrm{N}{\mathrm{H}}_3\right)}_4$ ${\left(\mathrm{N}{\mathrm{O}}_3\right)}_2$. The character of the Cu${\left(\mathrm{N}{\mathrm{H}}_3\right)}_4^{++}$ group was analyzed and it was found that the $g$ values of this group are small compared with that of the Cu${\left({\mathrm{H}}_2\mathrm{O}\right)}_4^{++}$ group. This can be explained by two methods, one of which is the covalent bonding hypothesis, the other being the usual ionic hypothesis. The exchange interaction of these salts is very large, which is considered to be the result of covalent bonding structure.