The first pentanuclear heterobimetallic coordination cation with CeIII, CeIV and MnII

[Mn2(μ-dipic)2(H2O)6]·2H2dipic (dipic = dipicolinate) reacts with (NH4)2[Ce(NO3)6] to produce the pentanuclear coordination species in [MnCe4(μ-dipic)6(H2O)20][Ce(dipic)3]2·11H2O (1). The coordination anion [Ce(dipic)]2− is formed by three tridentate O,N,O dipicolinate(2−) anionic ligands around the metal CeIV cation. The same pattern is found for two CeIV in the pentanuclear CeIII/CeIV/MnII/CeIV/CeIII chain-like coordination cation [MnCe4(μ-dipic)6(H2O)20]4+. The CeIV(dipic)3 moieties in the cation coordinatively bridge the terminal CeIII(H2O)8 with the central MnII(H2O)4 units. Each manganese(II) ion is thus 6-coordinated and each cerium(III, IV) ion is 9-coordinated. During the synthesis of 1, the gaseous dioxygen is evolved, due to water oxidation that is attributed to the presence of Ce and Mn in different oxidation states.