Xiutang Zhang

Syntheses, crystal structures, and properties of five mixed-ligand coordination polymers based on novel quaterphenyl-2,5,2′,5′-tetracarboxylic acid ligand

Solvothermal reactions of aromatic quaterphenyl-2,5,2′,5′-tetracarboxylic acid (H4qptc) ligand and transitional metal cations of MII (M = Co, Ni, Mn, Cu, Zn) in the presence of 1,10-phenanthroline (phen) afford five new coordination polymers (CPs), namely, {[M(H2qptc)(phen)(H2O)2]·2H2O}n (M = Co (1), Ni (2)), [Mn(qptc)0.5(phen)(H2O)]n (3), [Cu(qptc)0.5(phen)]n (4) and [Zn3(Hqptc)2(phen)2(H2O)2]n (5). Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD) and thermogravimetric (TG) analyses. Complexes 1 and 2 are isostructures and each displays a one-dimensional (1D) zigzag chain, which further forms a 2D supramolecular architecture via inter-chain π⋯π interactions. Complex 3 possesses a (3,6)-connected CdI2 layered architecture incorporating left- and right-handed helical chains. Complex 4 exhibits a 3D porous structure with rare (3,6)-connected ant topology. Complex 5 shows a 3D (3,4,5)-connected network with (42.6)2(43.62.8)(45.64.8)2 topology. The results show that the conformations and coordination modes of H2qptc2−/qptc4− ligand are crucial factors for the formation of the different structures. Moreover, the photoluminescence of 5 has been investigated.

Supramolecular isomeric flat and wavy honeycomb networks: additive agent effect on the ligand linkages

Two genuine supramolecular isomers of Cd(II) coordination polymers with an identical formula of [Cd(pptp)(ox)]n (1a and 1b) (pptp = 2-(3-(4-(pyridin-4-yl)phenyl)-1H-1,2,4-triazol-5-yl)pyridine, H2ox = oxalic acid) have been hydrothermally synthesized and characterized. Both compounds possess the rod-like binuclear [Cd2(pptp)2] subunit, which are linked by the ox ligand to afford either a flat or wavy two-dimensional (2D) 63-hcb network, depending upon whether the additive agent is used for the reaction. The photoluminescence behaviour of the compounds was also discussed.

Syntheses, structures, and magnetic properties of five coordination polymers constructed from biphenyl-3,4′,5-tricarboxylic acid and (bis)imidazole linkers

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 Schlafli 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.

Syntheses, structures, and properties of a series of 2D and 3D coordination polymers based on trifunctional pyridinedicarboxylate and different (bis)imidazole bridging ligands

A series of 2D and 3D transition coordination polymers (CPs), {[M(bcpb)(1,4-bmib)0.5]·xH2O}n (M = Co (1), Cu (2), Ni (3), x = 1 for 1, 0 for 2 and 3), {[Co(bcpb)(4,4′-bibp)0.5(H2O)1.5]·1.5H2O}n (4), [Cu(bcpb)(4,4′-bibp)0.5(H2O)]n (5), {[Ni(bcpb)(4,4′-bimbp)(H2O)]·2.5H2O}n (6), [Co(bcpb)(4,4′-bimbp)]n (7), [Mn(pip)(MeOH)(H2O)]n (8), {[Ni(pip)(4,4′-bibp)0.5(H2O)]·2H2O}n (9), and {[Cu(pip)(4,4′-bimbp)]·4H2O}n (10), were synthesized under hydrothermal conditions in the presence of two trifunctional pyridinedicarboxylates and different (bis)imidazole bridging linkers (H2bcpb = 3,5-bis(4-carboxyphenyl)pyridine, H2pip = 5-(4-pyridyl)isophthalic acid, 1,4-bmib = 1,4-bis(2-methylimidazol-1-ylmethyl)benzene), 4,4′-bibp = 4,4′-bis(imidazol-1-yl)biphenyl, 4,4′-bimbp = 4,4′-bis(imidazol-1-ylmethyl)biphenyl). Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analyses. Single crystal X-ray diffraction analyses reveal that complexes 1–3 are isomorphic and show complicated 3D (3,5)-coordinated amd networks, which could be viewed as two interpenetrated ths nets. Complex 4 is a binodal (3,4)-connected 3D framework with the Schlafli symbol of (4·72)(4·75·84). Complex 5 exhibits an intriguing 3D 2-fold interpenetrated network with the (3,4)-connected dmc net. Complex 6 is a 2D (3,5)-connected gek1 net with right- and left-handed [Ni(4,4′-bibp)]n helical chains arranged alternately. The 3D framework of 7 is defined as a 2-fold interpenetrated (3,5)-connected gra topology. Complex 8 displays a 2D 3-connected 63-hcb network. Complex 9 can be regarded as a (3,4)-coordinated crs-d network with a point symbol of (62·8)(63·8·102), which contains two interpenetrated 3-coordinated 103srs subnets linked by 2-coordinated 4,4′-bibp. Complex 10 is a binodal (3,5)-connected 3D framework with point Schlafli symbol of (4·6·8)(4·64·85). To the best of our knowledge, the 3D CPs with (3,4)-connected (4·72)(4·75·84) for 4, and (3,5)-connected (4·6·8)(4·64·85) for 10 have never been documented up to now. Moreover, the magnetic properties of 4 have been investigated.

Coligand syntheses, crystal structures, luminescence and photocatalytic properties of five coordination polymers based on rigid tetracarboxylic acids and imidazole linkers

Five coordination polymers (CPs) with distinct structures, namely, [Cu(H2tptc)(1,4-bidb)]n (1), {[Co2(tptc)(1,3,5-tib)(H2O)]·7H2O}n (2), {[Ni(tptc)0.5(1,3-bimb)]·H2O}n (3), {[Zn(qptc)0.5(1,4-bimb)]·3H2O}n (4), and {[Zn(qptc)0.5(1,3-bimb)]·H2O}n (5) (H4tptc = terphenyl-3,3′′,5,5′′-tetracarboxylic acid, H4qptc = quaterphenyl-3,3′′′,5,5′′′-tetracarboxylic acid, 1,4-bidb = 1,4-bis(1-imidazol-yl)-2,5-dimethyl benzene, 1,3,5-tib = 1,3,5-tris(1-imidazol-yl)benzene, 1,3-bimb = 1,3-bis(imidazol-1-ylmethyl)benzene, and 1,4-bimb = 1,4-bis(imidazol-1-ylmethyl)benzene), have been synthesized through a mixed ligand strategy. Complex 1 features a new 3D (4,6)-connected net with a Schlafli symbol of (42·64)(42·68·7·84). Complex 2 displays a 3D 2-fold interpenetrated framework with an unprecedented (3,3,4,4)-connected (6·82)2(62·83·10)(62·84) topology. Complex 3 exhibits a (32·62·72)-kgm layer featuring a 2D + 2D → 3D packing supramolecular structure interweaved through [Ni(1,3-bimb)] lock knots. Complex 4 shows an unprecedented 3D (4,4)-connected 86 net. Complex 5 is also a 2D + 2D → 3D supramolecular structure featuring kgm sheets hinged together through [Zn(1,3-bimb)] lock knots. In addition, the luminescence properties of 4 and 5 have been investigated. Moreover, complexes 1–3 show relatively good photocatalytic activities for methylene blue (MB) dye degradation in aqueous solution under UV light.

Syntheses, structures, and magnetic properties of six coordination polymers based on 4,5-di(4′-carboxylphenyl)phthalic acid and different bis(imidazole) bridging linkers

Six 4,5-di(4′-carboxylphenyl)phthalic acid (H4DCP) based coordination polymers (CPs), namely {[Ni(1,4-bib)(HDCP)2(H2O)2]0.5[Ni(1,4-bib)(H2O)4]·2H2O}n (1), [Ni(H2DCP)(1,4-bidb)2(H2O)]n (2), [Co2(DCP)(1,3-bib)]n (3), {[Co2(DCP)(1,4-bidb)2]·2H2O}n (4), [Co(H2DCP)(4,4′-bibp)]n (5), and [Co2(DCP)(4,4′-bibp)2]n (6), were synthesized under hydrothermal conditions in the presence of bis(imidazole) bridging linkers (1,3-bib = 1,3-bis(imidazol-1-yl)benzene, 1,4-bib = 1,4-bis(imidazol-1-yl)benzene, 1,4-bidb = 1,4-bis(imidazol-1-yl)-2,5-dimethyl benzene, 4,4′-bibp = 4,4′-bis(imidazol-1-yl)biphenyl). Their structures have been determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analysis. Single crystal X-ray diffraction analysis reveals that complex 1 is a cocrystal consisting of two independent chains. Complex 2 exhibits a traditional 2-fold 66-dia parallel entangled network. Complex 3 displays a novel 3D binodal (5,7)-connected net based on binuclear {Co2} units with the Schlafli symbol (3·44·54·6)(32·48·58·63). Complex 4 shows a 2-fold binodal (4,4)-connected bbf net with the point symbol (64·86)(66)2. Complex 5 affords a 2D (44·62)-sql net constructed from {Co2} dinuclear units. Complex 6 displays a novel (3,8)-connected architecture with the Schlafli point symbol (42·5)2(44·510·68·74·82) based on {Co4(COO)6} SBUs. Magnetic studies indicate complexes 3 and 6 exhibit weak ferromagnetic and antiferromagnetic properties, respectively.

Syntheses, structures, and luminescence of four lanthanide metal–organic frameworks based on lanthanide-oxide chains with C2- or C3-symmetric trigonal-planar polycarboxylate ligands

Solvothermal reactions of two trigonal-planar ligands and lanthanide metal cations of LnIII afford four new coordination polymers (CPs), {[LnNa0.33H0.67(PBPP)2]·2H2O}n (Ln = Pr for 1, Gd for 2, Ce for 3) and {[Sm(TATB)(H2O)]}n (4) (H2PBPP = 4-phenyl-2,6-bis(4′-carboxyphenyl)pyridine, H3TATB = 4,4′,4′′-s-triazine-2,4,6-tribenzoic acid). Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD) and thermogravimetric (TG) analyses. Complexes 1–3 are isomorphous and exhibit an unprecedented (4,6,6)-connected 3D architecture, which is built up from lanthanide-oxide chains. Complex 4 shows a 3D (6,6)-connected net with (44.67.84)6(48.67) topology, in which TATB3− is extremely unsymmetrical due to three metal-oxide chains in the directions of [101], [101] and [110]. Moreover, their luminescent properties have been investigated.

Assembly of a series of d10 coordination polymers based on W-shaped 1,3-di(2′,4′-dicarboxyphenyl)benzene: from syntheses, structural diversity, luminescence, to photocatalytic properties

Solvothermal reactions of W-shaped 1,3-di(2′,4′-dicarboxyphenyl)benzene (H4DDB) and zinc(II) or cadmium(II) salts in the presence or absence of three ancillary bridging imidazole linkers afford six CPs, namely, [Zn(H2DDB)(H2O)2(μ2-H2O)]n (1), [Zn2(DDB)(1,4-bimb)]n (2), [Zn2(DDB)(1,3-bimb)]n (3), {[Zn4(DDB)(HDDB)(1,3-bmib)2Cl]·H2O}n (4), {[Cd2(DDB)(1,3-bimb)]·H2O}n (5), and {[Cd2(DDB)(1,3-bmib)(H2O)0.5]·H2O}n (6), (1,3-bimb = 1,3-bis(imidazol-1-ylmethyl)benzene, 1,4-bimb = 1,4-bis(imidazol-1-ylmethyl)benzene, and 1,3-bmib = 1,3-bis(2-methylimidazol-1-ylmethyl)benzene). Complex 1 is composed of [Zn(H2DDB)(H2O)2(μ2-H2O)]n chains, which are further extended to a 3D supramolecular structure via hydrogen bonds. Complexes 2 and 3 exhibit the same (3,4,6)-connected net with the Schlafli symbol (52·62·8·9)(52·6)2(54·64·72·83·9·10) built from two kinds of SBUs: [Zn2(COO)4] and [Zn2(COO)2], while complex 4 is another (3,4,6)-connected net with the Schlafli symbol (3·4·5·62·7)(3·4·5·67·73·82)(3·72), based on the same [Zn2(COO)2] and [Zn2(COO)4] SBUs. The two CdII complexes of 5 and 6 display 3D (3,10)-connected (410·632·83)(43)2 nets, consisting of {Cd4(COO)8} and [Cd4(COO)8(μ2-H2O)] SBUs, respectively. The thermal stability and luminescence properties of complexes 1–6 have been investigated. In addition, complexes 1–6 show excellent photocatalytic activity for methylene orange (MO) dye degradation in aqueous solution under UV light. And complexes 2–6 exhibit relatively good chemical stability in aqueous solutions with pH regulated from 2 to 12.

Structural diversity of five coordination polymers based on 2,6-bis(3,5-dicarboxyphenyl)pyridine ligand: solvothermal syntheses, structural characterizations, and magnetic properties

Five new coordination polymers (CPs) with distinct structures and topologies, namely, {[Cu(H2BDP)(bib)]0.5·H2O}n (1), {[Co1.5(HBDP)(bib)2(H2O)]·3H2O}n (2), {[Co2(BDP)(bib)2]·H2O}n (3), {[Mn(BDP)0.5(bib)1.5(μ2-H2O)0.5(H2O)]·0.5H2O}n (4), and {[Fe2(BDP)(bib)(H2O)]·H2O}n (5) (H4BDP = 2,6-bis(3,5-dicarboxyphenyl)pyridine, bib = 1,4-bis(imidazol-1-yl)benzene), have been synthesized by systematically tuning the ratios of mixed solvent and pH values. Along with the altering ratios of the mixed-solvent DMF/H2O or CH3OH/H2O used in the synthetic processes, the coordination modes of the ligand change, which further lead to the different structures of resultant complexes. Owing to diverse metal centers and distinct ligand coordination modes, these five complexes exhibit totally diverse structures. Complex 1 displays a 2D 4-connected (44·62)-sql wave-like sheet, which is further expanded to a 3D supramolecular structure via the π⋯π interactions. In complex 2, 1D [Co(bib)]n straight chains and 1D [Co2(bib)3]n ladder-like chains interacted with each other to form a 2D net, which are linked by HBCP3− ligands to generate a 3D (3,4,5)-connected (42·64·73·9)2(62·7)2(64·7·8) architecture. Complex 3 exhibits an unprecedented 3D (4,4,8)-connected net with a Schlafli symbol of (3·42·52·6)4(32·44·54·64·72·86·95·10). Complex 4 exhibits a dinuclear {Mn2(μ2-H2O)} based 3D (4,8)-connected (63)(69·8)-gra framework. For complex 5, the whole structure can be regarded as a {Fe2(COO)4} binuclear SBU-based 3D architecture with (4,6)-connected (44·610·8)(44·62) topology. Besides, the magnetic properties of complexes 3–5 have been investigated.

Syntheses, structures, and luminescence properties of four metal–organic polymers with undocumented topologies constructed from 3,5-bis((4′-carboxylbenzyl)oxy)benzoate ligand

Solvothermal reactions of one semirigid tricarboxylic acid and transition metal cations in the absence or presence of 1,4-bis(1H-imidazol-4-yl)benzene (1,4-bib) afford four coordination polymers, namely, [Cd(Hbcb)]n (1), and [M(Hbcb)(1,4-bib)]n (M = Cd (2), Mn (3), Fe (4)) (H3bcb = 3,5-bis((4′-carboxylbenzyl)oxy)benzoic acid). Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analyses. Structural analysis revealed that complex 1 exhibits an intriguing [Cd(COO)2]n tube-like chain based 3D framework with unprecedented 6-connected (48·67) topology. Complexes 2–4 show isomorphism and show new 3D (3,5)-connected frameworks with the point Schlafli symbol of (4·6·8)(4·64·85) based on the [M(COO)]n chain. Moreover, the photoluminescence properties of 1 and 2 have been investigated in the solid state at room temperature.