Diverse structures of manganese(II) complexes based on 3,5-pyrazoledicarboxylic acid from discrete molecules to polymers

Four manganese(II) coordination complexes based on 3,5-pyrazoledicarboxylic acid (H3pdc) that are formulated as Mn2(H2O)8(Hpdc)2·3H2O, 1; Mn4(H2O)6(Hpdc)(pdc)2·H2O, 2; Mn(H2O)2(Hpdc), 3 and Mn(H2O)(Hpdc), 4, respectively, have been synthesized as single crystal particles via hydrothermal reactions. 1 crystallizes in the orthorhombic space group Pbcn, which is packed as discrete molecules and further forms a 3 dimensional (3-D) supramolecular framework via comprehensive hydrogen bonding interactions; 2 is formed in the monoclinic, P2(1)/n space group, which features as infinite 2-D inorganic connectivity layers linked via hydrogen bonds among these layers into a 3-D supramolecular framework; 3 has the structure of monoclinic, P2(1)/c, which can be viewed as infinite 1-D inorganic connectivity chains further generate a 3-D supramolecular framework via the hydrogen bonding around the chains; while 4 crystallizes in monoclinic P2(1)/n and is built into an open 3-D framework via the covalent bonds among nodes and pdc linkers. The photoluminescence of 2 and 3 are studied in room temperature.