Electronic structure of molecular superconductors containing paramagnetic 3d ions

The results of x-ray fluorescence measurements of the molecular superconduc tors (ET)(4)[(H3O)Fe(C2O4)(3)].C6H5CN (T-c = 8.5 K) and (ET)(4)[(H3O)Cr(C2O 4)(3)].C6H5CN (T-c similar to6 K) and molecular conductor (ET)(4)[(H3O)Fe(C 2O4)(3)].C5H5N containing paramagnetic 3d ions are presented. The following transition of the x-ray emission valence spectra are monitored: C K alpha, N K alpha (2p --> 1s transition) and Fe L-2.3, Cr L-2.3 (3d4s --> 2p(3/2.1 /2) transition). It is found that the electronic structure of the solvents (benzonitrile, pyridine) that occupy the hexagonal cavities formed by the a nionic layer is close to that of the neutral molecule. The ratio of the emi ssion intensities of the peaks L-2 to L-3 for Fe and Cr is found to be 2.8- 3.1 times higher for (ET)(4)[(H3O)Fe(C2O4)(3)].C6H5CN and (ET)(4)[(H3O)Cr(C 2O4)(3)].C6H5CN than for pure metals. This indicates that the paramagnetic 3d ions are situated in highly insulating anionic layers. We did not find a ny changes in the C K alpha emission for different solvent molecules.