Triple-quantum correlation NMR experiments in solids using J-couplings

We show that triple-quantum-single-quantum (TQ-SQ) correlation spectra of crystalline and disordered solids can be obtained under MAS using pulse sequences based on through-bond J-couplings. The feasibility of the experiments in coupled spin-1/2 systems is demonstrated for fully 13C-labelled l-alanine and Pb3P4O13 crystalline compounds, considered as model three-spin and four-spin systems, respectively. In the case of phosphate glasses, we show that the obtained TQ-SQ correlation spectra provide an improved description of the glass forming network connectivities and of the chain length distribution in the disordered network.