•Three isostructural CPs were synthesized based on a new linear rigid ligand.•The unique assembling way of expanding 1D chain to 2D bilayer structure in compounds 1–3 has not yet been reported.•Compound 3 exhibits a highly sensing ability to Ag+ ions.Three isostructural compounds [M(DPFE)(bpda)(H2O)2]n [M = Co(1), Mn(2), Cd(3)] have been synthesized hydrothermally and structurally characterized, where DPFE = 2,7-di(pyridin-4-yl)-9H-fluorene and H2bpda = biphenyl-3,4′-dicarboxylic acid. Compounds 1–3 show a unique 2D structure where exists two sets of chains toward two different directions. The solid-state UV–vis absorption spectra of 1–2 and the fluorescence spectrum of 3 are discussed in detail. In addition, compound 3 exhibits relatively high selective ability to detect Ag+ ion in aqueous media.Three isostructural compounds [M(DPFE)(bpda)(H2O)2]n [M = Co(1), Mn(2), Cd(3)] have been synthesized based on a new π-conjugated ligand, which show a unique assembling way of expanding 1D chain to 2D bilayer structure. Besides, compound 3 exhibits a highly sensing ability to Ag+ ions.

One of the most interesting phenomena in coordination polymers (CPs) is the co-existence of different interlaced motifs. However, CPs having two different interlaced motifs at the same time are still rare. Colourless block-shaped crystals of the two-dimensional polymer poly[[aqua(μ2-naphthalene-2,6-dicarboxylato){μ2-4,4′-[oxybis(4,1-phenylene)]dipyridine}cadmium(II)] monohydrate], {[Cd(C12H6O4)(C22H16N2O)(H2O)]·H2O}n, (I), was synthesized under hydrothermal conditions by the self-assembly of 4,4′-[oxybis(4,1-phenylene)]dipyridine (OPY) with CdII in the presence of naphthalene-2,6-dicarboxylic acid (H2ndc). Each CdII ion is six-coordinated by two N atoms from the pyridine rings of two OPY ligands and by four O atoms, three of which are from two ndc2− ligands and one of which is from a water molecule. In (I), every two identical two-dimensional (2D) 63 layers are interpenetrated in a parallel fashion, resulting in an interesting 2D2D framework with both polyrotaxane and polycatenane characteristics. The extension of these sheets into a three-dimensional supramolecular net is via O—H…O hydrogen bonds. The solid-state photoluminescence properties of (I) are also discussed.

•A pillar-layered-like MOF has been synthesized by a V-shaped bis-pyridyl ligand.•The symmetric N-donor ligand OPY adopts two different coordination modes.•The complex possesses high thermal stability.Solvothermal assembly of Co2 + ion, a V-shaped bis-pyridyl ligand with two different coordination modes and a tripodal multicarboxylate ligand yields a complicated 3D metal-organic framework, namely [Co(OPY)1.5(Hbtc)]n (1), [OPY = 4,4′-(oxybis(4,1-phenylene))dipyridine and H3btc = trimesic acid]. The compound 1 has been characterized by IR, elemental analysis, single crystal X-ray diffraction, XRD and TG analysis. Magnetic measurements performed on 1 indicate the occurrence of weak antiferromagnetic coupling between the neighboring Co2 + ions. In addition, the compound shows high thermal stability.A dinuclear Co based 3D framework has been synthesized by a semi-rigid V-shaped ligand and tripodal multicarboxylate ligand. The OPY ligand adopting two different coordination modes not only expands the dinuclear cobalt chain to a 3D CdSO4-type framework, but also enhance the stability of complex 1.Download high-res image (392KB)Download full-size image

•Two novel cobalt(II) coordination polymers constructed by a new V-shaped rigid ligand.•Compounds 1 and 2 present a 2D → 2D parallel entangled architecture with coexistence of polyrotaxane and polycatenane.•This is the first-known case of 2D → 2D polyrotaxane-like network constructed by rigid ligand.Two novel cobalt(II) coordination polymers (CPs), [Co(BPFP)2(sca)]n (1), [Co(BPFP)2(sda)]n (2), [BPFP = 2,8-di(pyridin-4-yl)dibenzo[b,d]furan, H2sca = succinic acid, H2sda = thiophene-2,5-dicarboxylic acid], have been synthesized hydrothermally based on a V-shaped rigid ligand BPFP. Their structures were fully characterized by elemental analysis, FT-IR spectroscopy and X-ray single-crystal diffraction methods. Compound 1 is a 2-fold parallel interpenetrating network consist of two identical sets of 2D layer motifs and shows both polyrotaxane and polycatenane characters. Compound 2 has the same structural feature as compound 1, except that the sca2− anions are replaced by the sda2− anions. The Powder X-ray diffraction (PXRD) analyses and thermogravimetric analyses were carried out to confirm the phase purity and the thermal stabilities of the compounds 1 and 2. In addition, the solid-state UV–vis absorption spectra were also investigated.

•A homochiral Cu(II) coordination polymer has been synthesized and characterized.•This chiral complex was constructed by two achiral V−shaped ligands.•The topology of this 3D complex represents a simple yet unreported 75∙8 topology.By using a V-shaped N-containing ligand and a V-shaped carboxylate ligand, we have successfully synthesized a 3D novel copper homochiral coordination polymer, namely [Cu(OPY)(1,3-bdc)]n (complex 1), [1,3-H2bdc = isophthalic acid, OPY = 4,4′-(oxybis(4,1-phenylene))dipyridine]. The compound has been solvothermally synthesized and characterized by IR, elemental analysis, single crystal X-ray diffraction, XRD, UV–vis, and TG analysis. The complex 1 crystallizes in the chiral space group P65 and possesses an unprecedented uninodal 3D 75∙ 8 topology. However, the complex was synthesized by achiral materials. The complex 1 displays a moderate SHG response and its SHG efficiency is about 0.3 times that of urea. In addition, the compound shows high thermal stability.A 3D non-interpenetrated chiral coordination polymer [Cu(OPY)(1,3-bdc)]n has been solvothermally synthesized by using V-shaped N-containing and multi-carboxylate ligands simultaneously without any chiral precursors. The structure of the complex is composed by the exclusively left-handed helical chains and each single chain is generated around the crystallographic 65 axis with a long pitch of 27.99 Å.

•A dinuclear Cd(II) based CP has been synthesized based on a new rigid ligand.•There exist two types of strong intramolecular π-π stacking interactions in the 2D layer.•Compound 1 displays intriguing structural feature and useful luminescent property in the green region.A new cadmium coordination polymer [Cd(DPFE)(adip)0.5(NO3)]n (1) has been synthesized hydrothermally from the self-assembly of the Cd2+ ion with a new π-conjugated rigid ligand DPFE and the adipic acid, where DPFE = 2,7-di(pyridin-4-yl)-9H-fluorene and H2adip = adipic acid. The structure of 1 was full characterized by elemental analysis, FT-IR spectroscopy and single crystal X-ray diffraction. Structural analysis reveals compound 1 is a dinuclear Cd(II) based two-dimensional (4,4) layer and two kinds of strong intramolecular π-π stacking interactions exist between pyridyl rings and benzene rings. In addition, the thermogravimetric analysis and solid–state luminescent properties have also been investigated.