Nuclear Magnetic Resonance in Some Pyrophosphates

Abstract

<p>The nuclear magnetic resonance of ³¹p has been studied in Mn₂P₂O₇, Co₂P₂O₇, Cu₂P₂O₇ and Ni₂P₂O₇. The resonances were found to be shifted from the predicted field due to the delocalization of unpaired electrons from the paramagnetic ions. The fraction of an unpaired electron present in the phosphorus 3s orbital arising from each metal-oxygen-phosphorus transfer path is 0.110% in Mn₂P₂O₇ and ~ 0.05% in the other compounds studied. The difference in these values is discussed in terms of the structure and bonding of the P₂O₇^4- anions.</p>