Application of the through-bond correlation NMR experiment to the characterization of crystalline and disordered phosphates

Abstract

Through-bond correlation NMR experiments have been used to characterize the structure of MP 2 O 7 crystalline compounds and disordered phosphates. For MP 2 O 7 materials, the refocused INADEQUATE experiment allows discrimination between the possible space group symmetries of the room temperature structure. The results show that the room temperature structure of ZrP 2 O 7 adopts Pbca symmetry. For lead phosphate glasses, the refocused INADEQUATE experiment can be used to determine the P–O–P through-bond connectivities between the different types of PO 4 tetrahedra. In these glasses, a correlation between the distributions of J -couplings and 31 P isotropic chemical shifts is shown by using the 2D J-resolved experiment.