title: Two different anionic manganese(II) coordination polymers constructed through dicyanamide coordination bridges.
abstract: In order to explore new metal coordination polymers and to search for new types of ferroelectrics among hybrid coordination polymers, two manganese dicyanamide complexes, poly[tetramethylammonium [di-μ3-dicyanamido-κ(6)N(1):N(3):N(5)-tri-μ2-dicyanamido-κ(6)N(1):N(5)-dimanganese(II)]], {[(CH3)4N][Mn2(NCNCN)5]}n, (I), and catena-poly[bis(butyltriphenylphosphonium) [[(dicyanamido-κN(1))manganese(II)]-di-μ2-dicyanamido-κ(4)N(1):N(5)]], {[(C4H9)(C6H5)3P]2[Mn(NCNCN)4]}n, (II), were synthesized in aqueous solution. In (I), one Mn(II) cation is octahedrally coordinated by six nitrile N atoms from six anionic dicyanamide (dca) ligands, while the second Mn(II) cation is coordinated by four nitrile N atoms and two amide N atoms from six anionic dca ligands. Neighbouring Mn(II) cations are linked together by μ-1,5- and μ-1,3,5-bridging dca anions to form a three-dimensional polymeric structure. The anionic framework exhibits a solvent-accessible void of 289.8 Å(3), amounting to 28.0% of the total unit-cell volume. Each of the cavities in the network is occupied by only one tetramethylammonium cation. In (II), each Mn(II) cation is octahedrally coordinated by six nitrile N atoms from six dca ligands. Neighbouring Mn(II) cations are linked together by double dca bridges to form a one-dimensional polymeric chain, and C-H...N hydrogen-bonding interactions are involved in the formation of the one-dimensional layer structure.
authors.affiliation: College of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, People's Republic of China.
authors.forename: Hui Ting
authors.initials: HT
authors.lastname: Wang
keywords: bridging dicyanamide; crystal engineering; crystal structure; hydrogen-bonding interactions; manganese(II) complex; one-dimensional polymeric chain; phase-transition materials; three-dimensional coordination polymer