EXAFS Studies of Cobalt(II) Complexes with Amino Acids
- Physics Department, Government Post-Graduate Arts and Science College, Ratlam 457001 (India)
- Mandsaur Institute of Technology, Mandsaur 458001 (India)
- School of Studies in Physics, Vikram University, Ujjain 456010 (India)
X-ray K-absorption edges along with their extended X-ray absorption fine structure (EXAFS) have been recorded for Co(II) complexes with amino acids using a laboratory XAFS spectrometer. The samples studied are biologically important because amino acids are very small bio molecules and are the principal building blocks of proteins and enzymes. The samples studied include cobalt glycinate, cobalt alanate, cobalt valinate and cobalt glutamate. Using the experimentally observed X-ray absorption chemical shifts, effective nuclear charge (ENC) and percentage covalency have been estimated and a relative order of covalency amongst the studied complexes established which follows the sequence: alanate > glutamate > glycinate > valinate. Both X-ray absorption near edge structure (XANES) and EXAFS have been utilized to obtain the average near neighbour distances in the samples. Further, the total phase shifts {delta}1 and phase parameters {beta}1 i.e., back scattering phase shifts for these samples have been estimated. The values of {beta}1 support the view that the environment around the central metal ion cobalt is similar in these complexes. The appearance of white lines (WL) at the K-absorption edges in these samples is discussed.
- OSTI ID:
- 21054625
- Journal Information:
- AIP Conference Proceedings, Vol. 882, Issue 1; Conference: XAFS13: 13. international conference on X-ray absorption fine structure, Stanford, CA (United States), 9-14 Jul 2006; Other Information: DOI: 10.1063/1.2644518; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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