Synthesis and solid-state NMR study of chromium complexes of per(3,6-anhydro)-α-cyclodextrin based polymers

This work presents the synthesis strategy, the structural characterization and the molecular dynamic properties of decontaminant polymers based on modified cyclodextrins. The polymers were made of per(3,6-anhydro)-α-cyclodextrin with either 2,4-diisocyanatotolylene, 1,4-diisocynatophenylene, 1,6-diisocyanatohexane or 1,12-diisocyanatododecane to bridge the modified cyclodextrin moiety. On the starting polymers and their metal complexes, the structural studies were carried out using classical 1D and 2D solid-state NMR experiments such as 2D WISE, along with the measurements of the time constants TCH, T1ρH and T1C. Information obtained on the changes in mobility of these different starting polymers gives insights into their ability to extract dichromate. The molecular sites of interactions between the oxoanions and the polymers could be also determined from these experiments and appear to be dependant upon the nature of the cross-linking agents.