title: 'Click' functionalization of cryogels conveniently verified and quantified using high-resolution MAS NMR spectroscopy.
abstract: Chemical modification reactions of alkyne containing polyHEMA-based macroporous network structures (cryogels) by Cu(I) catalyzed azide-alkyne 'click' cycloaddition reactions and their monitoring and quantification with high-resolution magic angle spinning (hr-MAS) NMR spectroscopy are reported. Complete conversion is obtained when benzylazide is reacted with the grafted alkyne function, but only partial conversion is observed when using azide-modified poly(ethylene glycol) (PEG-N(3) ). Subsequent addition of benzylazide consumes all remaining alkyne groups. All chemical modifications are easily monitored at each stage using hr-MAS NMR spectroscopy. The alkyne functionality and the resulting triazole ring provide well resolved (1) H resonances to monitor and quantify the progress of such 'click' reactions in general.
authors.affiliation: Polymer Chemistry Research Group, Department of Organic Chemistry, Ghent University, Krijgslaan 281, S4, 9000 Ghent, Belgium.
authors.forename: Wim
authors.initials: W
authors.lastname: Van Camp
authors.forename: Tugba
authors.initials: T
authors.lastname: Dispinar
authors.forename: Bart
authors.initials: B
authors.lastname: Dervaux
authors.forename: Filip E Du
authors.initials: FE
authors.lastname: Prez
authors.forename: José C
authors.initials: JC
authors.lastname: Martins
authors.forename: Bernd
authors.initials: B
authors.lastname: Fritzinger