A new supramolecular assembly based on triple-Dawson-type polyoxometalate and 3d-4f heterometallic cluster.

The introduction of hexavacant Dawson-type precursor K(12)[H(2)P(2)W(12)O(48)] x 24 H(2)O into a HOAc/NaOAc (OAc(-) = acetate) buffer system containing (NH(4))(2)[Ce(IV)(NO(3))(6)] and Mn(II)(OAc)(2) x 4 H(2)O led to the isolation of a new compound, Na(20)[Ce(IV)(3)Mn(IV)(2)O(6)(OAc)(6)(H(2)O)(9)](2)[Mn(III)(2)P(2)W(16)O(60)](3) x 21 H(2)O (1). Compound 1 contains unusual triple-Dawson-type polyoxoanions [Mn(III)(2)P(2)W(16)O(60)](3)(24-) and bipyramid-like 3d-4f heterometallic clusters [Ce(IV)(3)Mn(IV)(2)O(6)(OAc)(6)(H(2)O)(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, P6(3)/mcm (No. 193), a = 24.959(4) A, c = 26.923(5) A, gamma = 120 degrees, V = 14525(4) A(3), and Z = 2. The electrochemical and electrocatalytic properties of compound 1 have been investigated.