title: NEXAFS Sensitivity to Bond Lengths in Complex Molecular Materials: A Study of Crystalline Saccharides.
abstract: Detailed analysis of the C K near-edge X-ray absorption fine structure (NEXAFS) spectra of a series of saccharides (fructose, xylose, glucose, galactose, maltose monohydrate, α-lactose monohydrate, anhydrous β-lactose, cellulose) indicates that the precise determination of IPs and σ* shape resonance energies is sensitive enough to distinguish different crystalline saccharides through the variations in their average C-OH bond lengths. Experimental data as well as FEFF8 calculations confirm that bond length variations in the organic solid state of 10(-2) Å can be experimentally detected, opening up the possibility to use NEXAFS for obtaining incisive structural information for molecular materials, including noncrystalline systems without long-range order such as dissolved species in solutions, colloids, melts, and similar amorphous phases. The observed bond length sensitivity is as good as that originally reported for gas-phase and adsorbed molecular species. NEXAFS-derived molecular structure data for the condensed phase may therefore be used to guide molecular modeling as well as to validate computationally derived structure models for such systems. Some results indicate further analytical value in that the σ* shape resonance analysis may distinguish hemiketals from hemiacetals (i.e., derived from ketoses and aldoses) as well as α from β forms of otherwise identical saccharides.
authors.affiliation: School of Chemical Engineering and Analytical Science, The University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.
authors.forename: Adrian
authors.initials: A
authors.lastname: Gainar
authors.affiliation: School of Chemical Engineering and Analytical Science, The University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.
authors.forename: Joanna S
authors.initials: JS
authors.lastname: Stevens
authors.affiliation: Material Measurement Laboratory, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States.
authors.forename: Cherno
authors.initials: C
authors.lastname: Jaye
authors.affiliation: Material Measurement Laboratory, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Fischer
authors.affiliation: School of Chemical Engineering and Analytical Science, The University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.|School of Chemical and Process Engineering, University of Leeds , Leeds LS2 9JT, United Kingdom.|DIAMOND Light Source Limited , Harwell Science and Innovation Campus, Chilton, Didcot OX11 0DE, United Kingdom.
authors.forename: Sven L M
authors.initials: SL
authors.lastname: Schroeder
mesh_terms: D002236:Carbohydrate Conformation; D003460:Crystallization; D004187:Disaccharides / Q000737:chemistry*; D009005:Monosaccharides / Q000737:chemistry*; D056928:X-Ray Absorption Spectroscopy / Q000379:methods*
chemical_list: D004187:Disaccharides; D009005:Monosaccharides