  We have examined the local 3d electronic structures of Co-Au multinuclear
complexes with the medicinal molecules D-penicillaminate (D-pen)
[Co{Au(PPh3)(D-pen)}2]ClO4 and [Co3{Au3(tdme)(D-pen)3}2] by Co L_2,3-edge soft
X-ray absorption (XAS) spectroscopy, where PPh3 denotes triphenylphosphine and
tdme stands for 1,1,1-tris[(diphenylphosphino)methyl]ethane. The Co L_2,3-edge
XAS spectra indicate the localized ionic 3d electronic states in both
materials. The experimental spectra are well explained by spectral simulation
for a localized Co ion under ligand fields with the full multiplet theory,
which verifies that the ions are in the low-spin Co3+ state in the former
compound and in the high-spin Co2+ state in the latter.
