We have measured XANES (X-ray Absorption Near Edge Spectra) near the Re Li (i=l,II,III) edges in (TMTTF)2Re04 and (TMTSeF) 2Re04 and the Se K edge in the latter compound. An important dependence of the XANES at the Se K edge on the polarisation of the incident beam with respect to the crystal axes was observed, whose interpretation can give information on the symmetry of the unoccupied conduction band states. The positions of the Re L edges were compared with those in several inorganic compounds containing Re in various oxidation states, and were found to be, within experimental error, the same as those in KRe04, suggesting the molecular environment in the organic materials affects little the chemical state of the perrhenate anion.
Juana Vivó Acrivos and S.S. P. Parkin. "XANES in (TMTSeF)2Re04: Polarization Dependence of the Se K-Edge" Journal de Physique (1983): C3-1011-C3-1015. doi:10.1051/jphyscol/1983127