X-Ray Absorption
Spectroscopy
X-ray Absorption
Spectroscopy
X-ray absorption spectroscopy (XAS) techniques probe short- and medium-range order, yielding information on bond lengths, coordination numbers, local coordination geometry and the oxidation state of atoms for a wide range of solid and liquid systems. XAS experiments require an intense, tunable photon source only available at synchrotrons.
Features
• medium and high energy (from atomic number Z=20 upwards) XAS, XANES (x-ray absorption near-edge structure), XAFS (extended x-ray absorption fine structure) and XES (x-ray emission spectroscopy)
• bright and highly stable scanned monochromatic photon beam covering a large energy range
• accessible elements are Ca to Nd (K edge) and
Pm to U (L edge with k > 15Å-1)
• the EXAFS region of an XAS spectrum provides structural information such as bond length, coordination number and disorder
• the XANES region provides chemical information such as local coordination geometry and oxidation state
• fast-scanning XAS can be used to develop methodologies for determining the structures of intermediates in biochemically-important enzymatic processes. Applications
Around the world, XAS beamlines are in high demand for applications in the biological, chemical, earth, environmental, materials and physical sciences and engineering. The technique complements protein crystallography studies, and the two are frequently used in combination to determine challenging structures. Widely used by both specialists and non-specialists, XAS is a mature technology that is also enabling the advancement of new areas of science.
Examples
• identification of therapeutic target sites, such as the metal-binding sites that may be responsible for some of the pathological effects of Alzheimer’s disease
• elucidation of the chemistry associated with enzyme catalysis, particularly in relation to the influence of redox or charge state on the electronic and molecular structure of
Spectroscopy
X-ray absorption spectroscopy (XAS) techniques probe short- and medium-range order, yielding information on bond lengths, coordination numbers, local coordination geometry and the oxidation state of atoms for a wide range of solid and liquid systems. XAS experiments require an intense, tunable photon source only available at synchrotrons.
Features
• medium and high energy (from atomic number Z=20 upwards) XAS, XANES (x-ray absorption near-edge structure), XAFS (extended x-ray absorption fine structure) and XES (x-ray emission spectroscopy)
• bright and highly stable scanned monochromatic photon beam covering a large energy range
• accessible elements are Ca to Nd (K edge) and
Pm to U (L edge with k > 15Å-1)
• the EXAFS region of an XAS spectrum provides structural information such as bond length, coordination number and disorder
• the XANES region provides chemical information such as local coordination geometry and oxidation state
• fast-scanning XAS can be used to develop methodologies for determining the structures of intermediates in biochemically-important enzymatic processes. Applications
Around the world, XAS beamlines are in high demand for applications in the biological, chemical, earth, environmental, materials and physical sciences and engineering. The technique complements protein crystallography studies, and the two are frequently used in combination to determine challenging structures. Widely used by both specialists and non-specialists, XAS is a mature technology that is also enabling the advancement of new areas of science.
Examples
• identification of therapeutic target sites, such as the metal-binding sites that may be responsible for some of the pathological effects of Alzheimer’s disease
• elucidation of the chemistry associated with enzyme catalysis, particularly in relation to the influence of redox or charge state on the electronic and molecular structure of