Fig. 8. Natural abundance 13C (a) 1D CPMAS and (b) 2D refocused INADEQUATE NMR spectra of [2-17O]-α-d-glucose doped with 10% (w/w) Cu–EDTA. The dotted blue circle indicates the absence of the C6B signal due to its relatively short T2 (3.7 ms). Both spectra were obtained at 18.8 T with a Bruker 3.2 mm CPMAS CryoProbe. The sample spinning frequency was 15 kHz. Data acquisition parameters are: (a), 1D CP/MAS, contact time 3 ms, recycle time 3.7 s, 16 transients; (b), 2D refocused INADEQUATE, recycle delay 2 s, 1536 transients per t1, 34 t1 increments, J-evolution period of 3.99 ms, total experimental time 30 h.
