The reaction of the nitroxy radical 2,2,6,6‐tetramethylpiperidine‐N‐oxyl (TEMPO) with SiCl4 has been investigated in detail. One silicon‐containing product, TEMPO‐SiCl3 (1), could be isolated in crystalline form, and its crystal structure was determined. The structural parameters have been compared with the related hydroxylaminotrichlorosilane known from the literature and with DFT calculations. According to the calculations, the formation of 1 follows an SN2 mechanism, which is thermodynamically favored over an SN1 pathway. Upon hydrolysis, 1 decomposes and yields several TEMPO‐containing species. These were all characterized crystallographically.

The arrangement of cellulose molecules in natural environment on the nanoscale is still not fully resolved, with longitudinal disorder in cellulose microfibrils (CMF) being one relevant question. Particularly the length of the dislocated cellulose segments in CMFs is still under debate. Using molecular dynamics simulations, we are first investigating the phenomenon of pseudo-recrystallization of dislocated cellulose regions after cleavage of CMFs. Based on our simulations we propose that 3–4 glucose residues bordering to each side of a cellulose nanocrystal are actually reorganizing to a quasi-crystalline state, which are corroborating recent analytical investigations reporting an increase in crystallinity after acid vapor hydrolysis of CMFs. Combining our molecular dynamics simulation results with these analytical data we can estimate the length of the dislocated cellulose segments in CMFs. We propose that, for the investigated sources of biomass (cotton and ramie), the dislocation lengths are between 3.1–5.8 nm equaling to 6–11 glucose residues in the cellulose crystallites. Graphic abstract

After an introduction to polysaccharides in general and cationic polysaccharides in particular, a short overview on different fields of applications in regenerative medicine is given. Applications are manifold and range from wound healing and artificial skins to guided nerve and bone regeneration. However, the scope of this chapter is to give a short overview on the topic by explaining important examples in detail.

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