Octahedral Pd 2+ Coordination and Ferromagnetic Ordering in Pd(S 2 O 7 )

It's hip not to be square: The oxidation of elemental palladium with SO3 leads to Pd(S2O7) in which the Pd2+ is in an octahedral coordination environment of oxygen atoms (see structure Pd red, O blue, S yellow) and not the usual square-planar environment for Pd2+ species. This unexpected geometry leads to the observed paramagnetism of the compound with ferromagnetic ordering at 11.7 K.