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 (13)C-labelled L-alanine and Pb(3)P(4)O(13) 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. (c) 2005 Elsevier Inc. All rights reserved.