Electron Paramagnetic Resonance of Dipyridyl-Coordinated Ag2+(4d9)

The paramagnetic resonance spectrum of solid [Ag dipy₂] S₂O₈ and its solution in nitric acid have been observed at 77°K. The frozen solution exhibits silver hyperfine and nitrogen superhyperfine structure. Due to a strong axial $g$ anisotropy it is possible to determine the principal values of the hyperfine interaction tensors. With these values it is found that the hole in the silver $d$ shell is highly delocalized. Wavefunctions for the unpaired electron are calculated on the basis of the experimental results. Exchange narrowing in the solid wipes out the hyperfine structure.