Rare tetranuclear mixed-valent [(Mn2Mn2IV)-Mn-II] clusters as building blocks for extended networks

We report the synthesis of a series of mixed valence Mn-II/IV tetranuclear clusters [(Mn2Mn2O2)-Mn-II-O-IV(heed)(2)(EtOH)(6)Br-2]Br-2 (1), [(Mn2Mn2O2)-Mn-II-O-IV(heed)(2)(H2O)(2)Cl-4]center dot 2EtOH center dot H2O (2 center dot 2EtOH center dot H2O), [(Mn2Mn2O2)-Mn-II-O-IV(heed)(2)(heedH(2))(2)](ClO4)(4) (3), [(Mn2Mn2O2)-Mn-II-O-IV(heed)(2)(MeCN)(2)(H2O)(2)-(bpy)(2)](ClO4)(4) (4) and [(Mn2Mn2O2)-Mn-II-O-IV(heed)(2)(bpy)(2)Br-4]center dot 2MeOH (5 center dot 2MeOH). Clusters 1-5 are constructed from the tripodal ligand N,N-bis(2-hydroxyethyl) ethylene diamine (heedH2) and represent rare examples of tetranuclear Mn clusters possessing the linear trans zig-zag topology, being the first Mn-II/IV mixed-valent clusters of this type. The molecular clusters can then be used as building blocks in tandem with the (linear) linker dicyanamide ([N(CN)(2)](-), dca(-)) for the formation of a novel extended network {[(Mn2Mn2O2)-Mn-II-O-IV(heed)(2)(H2O)(2)(MeOH)(2)(dca)(2)]Br-2}(n) (6), which exhibits a rare form of the 2D herring bone topology.