Faster Magic Angle Spinning Reveals Cellulose Conformations In Woods

We present a first report on the detection of three different C6 conformers of cellulose in spruce, as revealed by solid-state H-1-C-13 correlation spectra. The breakthrough in H-1 resolution is achieved by magic-angle spinning in the regime of 150 kHz. The suppression of dense dipolar network of H-1 provides inverse detected C-13 spectra at a good sensitivity even in natural samples. We find that the glycosidic linkages are initially more ordered in spruce than maple, but a thermal treatment of spruce leads to a more heterogeneous packing order of the remaining cellulose fibrils.