EXAFS and XANES characterization of polymer coordination Schiff-base Co-containing complexes

We present an analysis of the extended X-ray absorption fine structure (EXAFS) and X-ray absorption near-edge structure (XANES) spectra at the cobalt K-edge in a series of Go-containing polymers prepared by reaction of the Schiff-base polymer (C13H17N3) and a CoX2 salt, where X=NO3, ClO4, Cl and (SO4)(1/2). The combined analyses of both EXAFS and XANES data confirms the formation of polymeric-coordination complexes as materials with a very low crystallinity. The cobalt atoms are found to be surrounded by 6 nitrogen atoms arranged in octahedral geometry, each Co ion being coordinated to two repetitive tridentate quelate units of the organic polymer. The change of this environment due to synthetic modifications, i.e., as a function of the different CoX2 salts used in the synthesis procedure, has been also determined.