2016. 57, 6 – UDC 548.73:541.49:546.711 CRYSTAL STRUCTURES OF TWO ONE-DIMENSIONAL COORDINATION POLYMERS CONSTRUCTED FROM Mn2+ IONS, CHELATING HEXAFLUORO-ACETYLACETONATE ANIONS, AND FLEXIBLE BIPYRIDYL BRIDGING LIGANDS M.J. Plater, B.M. De Silva, M.R. St J. Foreman, W.T.A. Harrison Department of Chemistry, University of Aberdeen, Aberdeen, Scotland E-mail: w.harrison@abdn.ac.uk Received April, 30, 2015 The syntheses and crystal structures of two one-dimensional coordination polymers, [Mn(C5HO2F6)2(C16H20N2)]n (1) and [Mn(C5HO2F6)2(C20H20N2)]n (2), are described, where 52 6 ing bipyridyl ligands to generate a cis-MnN2O4 octahedron. <...> The bridging ligands, which are completed by crystallographic inversion symmetry in both compounds, connect the metal nodes into zigzag [201 ] chains in 1 and contorted [001] chains in 2. <...> Intrachain C—H O interactions occur in 1 but not in 2, which may be correlated with the relative orientations of the ligands. <...> Our studies in this area have focused on bipyridyl ligands in which the pyridine rings are connected by a flexible —(CH2)n— (n = 3—7) alkyl chain, which can adopt different conformations and lead to a variety of polymeric structures in combination with different metal ions [ 5, 6 ] and counter ions such as nitrate or perchlorate ions. <...> The addition of a chelating ligand such as hfac– to the synthesis can modify the dimensionality of coordination networks and alter their properties as recent studies [ 12, 13 ] have demonstrated. <...> Pyridine-3-carboxaldehyde (2.72 g, 25.4 mmol) was added to a solution of 1,4-bis(methyl-triphenylphosphonium)benzene dibromide (10 g, 12.7 mmol) in dry ethanol (50 ml). <...> Both structures were solved by direct methods using SHELXS-97 in space group C2/c (No. 15) and the atomic models were developed and refined against |F|2 with SHELXL-97 [ 14 ]. <...> The O-bound H atoms in 1 were found in difference maps and refined as riding atoms in their as-found relative positions with Uiso(H) = 1.2Ueq(O). <...> The C-bound H atoms were geometrically placed and modelled as riding atoms with C—H = 0.95—0.99 Е and Uiso(H) = 1.2Ueq(C). <...> The structures were verified <...>