X-ray absorption spectroscopic studies on model compounds for biological iodine and bromine

• Published in: Journal of synchrotron radiation Vol. 12; no. 1; pp. 85 - 93
• Main Authors: Feiters, Martin C., Küpper, Frithjof C., Meyer-Klaucke, Wolfram
• Format: Journal Article Conference Proceeding
• Language: English
• Published: 5 Abbey Square, Chester, Cheshire CH1 2HU, England Munksgaard International Publishers 01.01.2005; Blackwell
• Subjects: bromine; Bromine Compounds - chemistry; Exact sciences and technology; EXAFS; Fourier Analysis; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; iodine; Iodine Compounds - chemistry; Laminaria; Laminaria - chemistry; model compounds; Molecular Structure; Physics; Spectrum Analysis - methods; Synchrotron radiation instrumentation; X- and γ-ray instruments and techniques; X-Rays; XANES; XAS; Fourier transformation; XANES; Organic bromine compounds; X-ray spectra; X-ray absorption; Form factors; EXAFS; Biological system; Aromatics; Biological compound; Organic iodine compounds; Valence; X-ray absorption spectra; Model compound; Synchrotron radiation
• ISSN: 1600-5775; 0909-0495; 1600-5775
• DOI: 10.1107/S0909049504027815

X‐ray absorption spectra of a number of organic iodine and bromine compounds of biological relevance, as well as of a series of iodine compounds with different oxidation states, have been measured. The iodine K‐edge spectra (XANES) are found to be relatively featureless but the position of the edge is found to be sensitive to formal valence (among other factors), and the edge shape to the number of bound O atoms. EXAFS spectra of organohalogen compounds (both iodine and bromine) can be used to discriminate between aliphatic and aromatic compounds. There are differences both in the distances from the halogens to the first shell of C atoms, which are shorter for aromatic compounds, and in the patterns of shells in the Fourier transforms. This result is expected to be relevant to studies at these edges in biological systems.