Heterometallic 3d-4f polyoxometalate derived from the weakley-type dimeric structure.

Polyanion [{Ce(H(2)O)(2)}(2)Mn(2)(B-alpha-GeW(9)O(34))(2)](8-) (1) constitutes the first example of a heterometallic 3d-4f cluster related to the Weakley-type dimeric structure, and it contains an unprecedented Ce(III)(2)Mn(III)(2)O(20) rhomblike moiety displaying dominant Ce(III)-Mn(III) ferromagnetic interactions.