title: Solution-State One- and Two-Dimensional NMR Spectroscopy of High-Molecular-Weight Cellulose.
abstract: High-molecular-weight celluloses (which even include bacterial cellulose) can be dissolved fully in methyltrioctylphosphonium acetate/[D6 ]DMSO solutions to allow the measurement of resonance-overlap-free 1 D and 2 D NMR spectra. This is achieved by a simple and non-destructive dissolution method, without solvent suppression, pre-treatment or deuteration of the ionic component. We studied a range of cellulose samples by using various NMR experiments to make an a priori assignment of the cellulose resonances. Chain-end resonances are also visible in the (1) H NMR spectrum. This allows the rough determination of the degree of polymerisation (DP) of a sample for low-DP celluloses by the integration of non-reducing chain ends C1 versus polymeric cellobiose C1. Low-DP celluloses show a good agreement with the gel-permeation chromatography (GPC) values, but high-DP pulps show more deviation. For high-purity pulps (pre-hydrolysis kraft and sulfite), residual xyloses and mannoses can also be identified from the (1) H-(13) C heteronuclear single-quantum coherence (HSQC) spectra. Resonances are thus assigned for the common polymeric polysaccharides found in chemical pulps.
authors.affiliation: Laboratory of Organic Chemistry, Department of Chemistry, University of Helsinki, A.I. Virtasen aukio 1 (Chemicum), PL 55, 00014 University of, Helsinki, Finland.
authors.forename: Ashley J
authors.initials: AJ
authors.lastname: Holding
authors.affiliation: Laboratory of Organic Chemistry, Department of Chemistry, University of Helsinki, A.I. Virtasen aukio 1 (Chemicum), PL 55, 00014 University of, Helsinki, Finland.
authors.forename: Valtteri
authors.initials: V
authors.lastname: Mäkelä
authors.affiliation: Department of Forest Products Technology, School of Chemical Technology, Aalto University, P.O. Box 11000, 00076, Aalto, Finland.
authors.forename: Lasse
authors.initials: L
authors.lastname: Tolonen
authors.affiliation: Department of Forest Products Technology, School of Chemical Technology, Aalto University, P.O. Box 11000, 00076, Aalto, Finland.
authors.forename: Herbert
authors.initials: H
authors.lastname: Sixta
authors.affiliation: Laboratory of Organic Chemistry, Department of Chemistry, University of Helsinki, A.I. Virtasen aukio 1 (Chemicum), PL 55, 00014 University of, Helsinki, Finland. ilkka.kilpelainen@helsinki.fi.
authors.forename: Ilkka
authors.initials: I
authors.lastname: Kilpeläinen
authors.affiliation: Laboratory of Organic Chemistry, Department of Chemistry, University of Helsinki, A.I. Virtasen aukio 1 (Chemicum), PL 55, 00014 University of, Helsinki, Finland. alistair.king@helsinki.fi.
authors.forename: Alistair W T
authors.initials: AW
authors.lastname: King
mesh_terms: D001419:Bacteria; D002482:Cellulose / Q000737:chemistry*; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D005052:Eucalyptus; D052578:Ionic Liquids / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D009861:Onium Compounds / Q000737:chemistry; D028222:Picea; D012996:Solutions
chemical_list: D052578:Ionic Liquids; D009861:Onium Compounds; D012996:Solutions; D002482:Cellulose; D004121:Dimethyl Sulfoxide
keywords: biomass; carbohydrates; ionic liquids; nmr spectroscopy; polymerization