EXAFS structural determination of the Pt2(P2O5H2)44- anion in solution

We present the first structural detn. of the Pt2(P2O5H2)44- anion in soln. by analyzing the extended X-ray absorption fine structure (EXAFS) spectrum of the Pt LIII edge. The data could be fit with a simple model involving single and multiple scattering paths to near and far P-atoms, bridging O-atoms, and the other Pt-atom in the binuclear complex. A Pt-Pt distance of 2.876(28) .ANG. and a Pt-P bond length of 2.32(4) .ANG. are obtained. These values are in line with distances found in previous X-ray diffraction studies. The assignment of the EXAFS spectrum of the Pt2(P2O5H2)44- anion in its ground state is required for future time-resolved X-ray absorption measurements with the goal of detg. the structure and dynamics of the complex in the 1,3A2u excited states.