Syntheses, structures, and magnetic properties of five coordination polymers constructed from biphenyl-3,4′,5-tricarboxylic acid and (bis)imidazole linkers†
Abstract
Five coordination polymers (CPs), namely {[Ni1.5(BPT)(1,4-bib)2(H2O)]·(1,4-bib)0.5·2H2O}n (1), {[Co2(BPT)(1,3-bimb)(μ3-OH)]·H2O}n (2), {[Zn(HBPT)(1,3-bimb)]·H2O}n (3), {[Co2(BPT)(H2BPT)(4,4′-bibp)2]·2H2O}n (4), and [Mn2.5(BPT)(4,4′-bibp)2.5(SO4)(H2O)]n (5) (H3BPT = biphenyl-3,4′,5-tricarboxylic acid, 1,4-bib = 1,4-bis(1H-imidazol-1-yl)benzene, 1,3-bimb = 1,3-bis(imidazol-1-ylmethyl)benzene, and 4,4′-bibp = 4,4′-bis(imidazol-1-yl)biphenyl), were synthesized under hydrothermal conditions. Their structures were determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectroscopy, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analyses. Complex 1 exhibits unprecedented 2D + 2D → 3D parallel entangled networks consisting of trilayer (3,4,6)-connected (44·54·66·8)(5·64·8)2(52·62) sheets. Complex 2 displays a 3D (3,10)-connected 3,10T9 net based on tetranuclear {Co4(μ3-OH)2} clusters with the Schläfli symbol (418·624·83)(43)2. Complex 3 shows an interesting 1D tube-like chain consisting of Zn2(1,3-bimb)2 loops. Complex 4 affords a 2D (44·62)-sql net constructed from {Co2} dinuclear units. Complex 5 displays a 3D 6-connected (412·63)-pcu net consisting of α-Po primitive cubic nets based on {Mn5(SO4)2} clusters. Moreover, magnetic studies indicate that complexes 2, 4 and 5 show antiferromagnetic properties.