Faster magic angle spinning reveals cellulose conformations in woods

Abstract

We present a first report on the detection of three different C6 conformers of cellulose in spruce, as revealed by solid-state ¹H–¹³C correlation spectra. The breakthrough in ¹H resolution is achieved by magic-angle spinning in the regime of 150 kHz. The suppression of dense dipolar network of ¹H provides inverse detected ¹³C 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.