Spatial structure of new heterometallic Ru/(Co, Ni, Cu or Zn) complexes in hexane by XAFS spectroscopy

Structural models have been proposed for heterometallic complexes that can be formed in extracts containing Ru anions and M cations (M=Cu, Zn, Co or Ni). Formation of these complexes is accompanied by Ru-O distance increase while the Ru-N distances are unchanged within the determination error. Clearly defined experimental maximum in the curves of 3d metals radial distribution functions gives an indication of Ru atom existence at the rigidly fixed distance and makes direct evidence of a rigid chemical bond between Ru- and M-containing fragments of the heterometallic complex. The obtained data indicate that double coordination of solvated 3d metals cations to the ruthenium complex could take place via the oxygen atom of the hydroxyl group and the NO fragment of the nitro group both linked to the ruthenium atom.