A New Supramolecular Assembly Based on Triple-Dawson-Type Polyoxometalate and 3d-4f Heterometallic Cluster.

The introduction of hexavacant Dawson-type precursor K12[H2P2W12O48]·24H2O into a HOAc/NaOAc (OAc− = acetate) buffer system containing (NH4)2[CeIV(NO3)6] and MnII(OAc)2·4H2O led to the isolation of a new compound, Na20[CeIV3MnIV2O6(OAc)6(H2O)9]2[MnIII2P2W16O60]3·21H2O (1). Compound 1 contains unusual triple-Dawson-type polyoxoanions [MnIII2P2W16O60]324− and bipyramid-like 3d−4f heterometallic clusters [CeIV3MnIV2O6(OAc)6(H2O)9]2+, which are arranged in a 3-D supramolecular assembly with 1-D channels. The Na+ cations and solvent water molecules reside in the channels. Crystal data for 1 are as follows: hexagonal, P63/mcm (No. 193), a = 24.959(4) A, c = 26.923(5) A, γ = 120°, V = 14525(4) A3, and Z = 2. The electrochemical and electrocatalytic properties of compound 1 have been investigated.