Three NMR spectrometers were used to collect the data in this report. The 13 C NMR data were collected on a 9.4 T wide bore magnet with a Bruker Avance NEO spectrometer using a 4 mm double resonance probe. For each experiment, pulse lengths were individually optimised on a reference material ( 13 Cadamantane, O -H 2 O(l)). For the 17 O quadrupolar π/2-pulse on the solid samples themselves, the low RF limit (ω Q > ω rf ) was invoked such that the π/2-pulse utilised was derived from 3 × ω rf measured on liquid H 2 O. Full experimental parameters for all spectra in this work are listed in Table .