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A double interlacing metal–organic framework (MOF), formula of [(Zn4O)2(PDDA)6(H2O)2]·10DMF (1), with pcu-topology has been successfully assembled by Zn4O inorganic clusters and a V-shaped ligand 4...

Two series of ten 3D porous coordination polymers (PCPs), [Ag(L434)](BF4)(DMF)2 (1·BF4·DMF), [Ag(L434)](BF4)(CH3CN)2 (1·BF4·CH3CN), [Ag(L434)](BF4)(DMA)(CH3OH) (1·BF4·DMA/CH3OH), [Ag(L434)](ClO4)(D...

The hard–soft-acid–base (HSAB) and dual-ligand strategies have been used to construct a pillar-layer luminescent metal–organic framework (MOF) {[Zn2(TRZ)2(DBTDC-O2)]·DMAc}n (1), in which H2DBTDC-O2 = S,S-dioxodibenzothiophen-3,7-dicarboxylic acid and HTRZ = 1,2,4-triazole. Thanks to its high stability in water and quadrangle microporous channels, MOF 1 can be served as a platform of recyclable multi-responsive luminescent sensor for Fe3+, Al3+, SiF62–, Cr2O72–, nitrofurantoin (NFT), and nitrofurazone (NFZ) in water. This is the first MOF-based sensor for detecting SiF62– anion via luminescent enhancement effect. Significantly, 1 also represents a unique example to probe NFZ or NFT by using transition metal MOFs in water, which exhibits the most sensitive sensing ability for NFZ (Ksv = 5.2 × 104 M–1) and NFT (Ksv = 1.8 × 105 M–1) via luminescent quenching.

Helix represents the most essential molecular chiral symmetry at a supramolecular level. Here, a unique quasiracemate conglomerate {[Cd(L)I(H2O)3][Cd(HL)I2(H2O)2](H2O)4}n (1, HL = N-(3,5-di(pyridin-3-yl)-4H-1,2,4-triazol-4-yl)nicotinamide), which crystallizes in P21 space group and consists of two different sets of helical enantiomers, has been successfully constructed. Remarkably, crystal transformations from the chiral quasiracemate 1 to two different achiral racemates {[Cd(L)I(H2O)3]·(H2O)3}n (2) and {[Cd(HL)I2(H2O)2](H2O)}n (3) can be achieved controllably by introducing acid and base additives, via solvent-mediated crystal transformations.

A series of AgI coordination polymers, {[Ag2L][Ag1/2(ONO)2(NO2)1/2](H2O)}n (1), {[AgL](BF4)}n (2), and {[Ag2L2](ClO4)2}n (3), have been prepared by assembly of AgX (X– = NO2–, BF4–, and ClO4–) with 3,4-bis(2-pyridyl)-5-(4-pyridyl)-1,2,4-triazole (L). Single-crystal X-ray diffraction analyses indicate that 1–3 show distinct two-dimensional networks and lattice stacking, with the counteranions [Ag1/2(ONO)2(NO2)1/2]2–, BF4–, and ClO4– located in the interlayered voids. Interestingly, when the crystals of 1 were immersed in a water solution of BF4– or ClO4– anion, 2 or 3 can be irreversibly formed via anion-driven structural transformation. This process has also been investigated by means of PXRD, elemental analysis, FT-IR, and SEM-EDS, revealing a solvent-mediated mechanism. Moreover, the dynamic anion-exchange behavior is highly anion-selective but cation-independent.

This work presents two unique entangled coordination polymers based on square Cd4-building blocks. Complex 1 represents the first example of 2D→ 3D parallel polycatenated architecture constructed from a 4·82-fes net, whereas complex 2 shows an unusual (3,4)-connected self- catenated network that can be viewed as the cross-linking of a 2D + 2D→3D inclined polycatenation.

Two chiral d10 metallosupramolecular systems based on an achiral fluorinated Schiff-base ligand have been prepared and characterized. The ZnII complex 1 reveals 21 helical coordination chains with ...

A series of novel metal–organic frameworks (MOFs) have been assembled from PbII and 2,3,5,6-tetrachloro-1,4-benzenedicarboxylic acid (H2BDC-Cl4) by simply adding different alkali metal ions as templates. When only lead nitrate is used, a robust 3D open framework [Pb(BDC-Cl4)(MeOH)2]n (1) with pts topology can be obtained. Incorporating the lighter LiI or NaI ions into the above PbII/BDC-Cl4 system results in two unique isostructural 3D PbII–LiI and PbII–NaI heterometallic frameworks, {[PbLi2(BDC-Cl4)(μ2-OH)2](H2O)}n (2) and [PbNa2(BDC-Cl4)(μ2-OH)2]n (3), which are built from the combination of a 3D rod-packing PbII-carboxylate framework and a 3D NaI–BDC-Cl4 (or LiI–BDC-Cl4) network. When the heavier KI ion is applied, the similar reaction affords a 3D MOF [Pb2(BDC-Cl4)2(DMF)3]n (4), which represents the first pillar-layered PbII coordination network with a (3,5)-connected gra topology. The results illustrate the powerful effect of the alkali-metal templates in MOFs assemblies. The solid-state properties s...

Hydrothermal reactions of CoII or ZnII acetate with benzene-1,2,3-tricarboxylic acid (H3bta) and 1,2-bi(4-pyridyl)ethane (bpa) afford two unique metal–organic frameworks, in which 1 represents a new type of entangled architecture formed via polycatenane of a pair of (4,4) net with one two-dimensional 3-connected self-interpenetrating pattern, while 2 shows a three-dimensional 4-connected net with a new trinodal topology.

A series of novel three-dimensional (3-D) lanthanide−organic frameworks (LnOFs), with the general formula [Ln2(H-L)3(H2O)4]∞ (Ln = DyIII for 1, GdIII for 2, TbIII for 3, EuIII for 4, and HoIII for 5; H-L = N-protonated 2,6-dihydroxypyridine-4-carboxylate), have been synthesized under hydrothermal conditions. X-ray structural analysis reveals that complexes 1−5 are isostructural and show the unique 3-D coordination framework with a trinodal (3,4,5)-connected (4.62)(42.6)(42.84)(43.6.86)(42.65.83) net topology, in which the H-L ligands adopt different μ4- and μ3-bridging forms. Variable-temperature magnetic susceptibility studies reveal that complexes 1−3 and 5 show ferromagnetic behaviors. Notably, complex 1 (DyIII) is the first instance leading to ferromagnetic coupling for a lanthanide ion through a spin-polarization mechanism. The alternating current (ac) signal observed for 1 and 5 should originate from the long-range ferromagnetic ordering, or it could reflect the splitting of the J multiplet for DyII...

Seven Zn(II) and Cd(II) coordination polymers, formulated as {[Zn2(5-Br-ip)2(bpy)(H2O)]·2H2O}n (1), {[Zn(5-Br-ip)(bpa)(H2O)]}n (2), {[Cd(5-Br-ip)(bpp)(H2O)]}n (3), {[Zn(5-Br-ip)(bpe)]}n (4), {[Zn2(4-Br-ip)2(bpy)]·H2O}n (5), {[Zn(4-Br-ip)(bpa)(H2O)]}n (6), and {[Cd(4-Br-ip)(bpp)]}n (7), were prepared by hydrothermal reactions based on 4-bromo- or 5-bromoisophthalic acid (4-Br-H2ip or 5-Br-H2ip) and different dipyridyl-type coligands 4,4′-bipyridyl (bpy), 1,2-bi(4-pyridyl)ethane (bpa), 1,3-di(4-pyridyl)propane (bpp), and 1,2-di(4-pyridyl)ethene (bpe). All complexes 1−7 were characterized by elemental analysis, IR spectra, and X-ray single-crystal diffraction. Complex 1 is a 2D (6,3) coordination network and further assembled into a 3D framework via π−π stacking interactions. Complex 2 shows a 1D coordination array and further forms a 2D supramolecular network via H-bonding interactions. Complex 3 has a 2-fold interpenetrating 3D diamond framework. Complex 4 is a 3-fold interpenetrating 3D network with CdSO4...

Under different solvothermal reaction conditions I (60 °C for 48 h) and II (140 °C for 72 h), the dipyrazinyl compounds bearing oxadiazole and triazole spacers, that is, 2,5-bis(2-pyrazinyl)-1,3,4-oxadiazole (L1) and 4-amino-3,5-bis(2-pyrazinyl)-1,2,4-triazole (L2), may suffer reversible conversions in the presence of certain metal salts. Other related derivatives such as 3,5-bis(2-pyrazinyl)-1,2,4-triazole-4-yl-N-pyrazinamide (HL4) and pyrazine-2-carboxylic acid (HL0) can also be (in situ) obtained from L1 and L2, respectively, under conditions I and II. Beyond this, N,N′-bis(2-pyrazineamide) (H2L3) can be in situ afforded from both precursors L1 and L2, and thus, may be considered as the potential intermediate during the interconversions. The possible mechanisms and influence factors of these reactions have also been established based on the experimental results. As a result, a variety of crystalline materials (co-crystals and coordination complexes) with attractive supramolecular architectures have bee...

A series of six CdII coordination complexes have been prepared by using naphthalene-2,3-dicarboxylic acid (H2ndc), an analogue of 1,2-benzenedicarboxylic acid (H2bdc), and different N-donor auxiliary co-ligands (chelating or bridging), namely, [Cd(ndc)]∞ (1), {[Cd2(ndc)2(2bpy)2(H2O)2](CH3OH)0.5}2 (2), [Cd2(ndc)2(phen)2]∞ (3), {[Cd(ndc)(4bpy)0.5(H2O)2](H2O)}∞ (4), {[Cd(ndc)(abp)(H2O)](H2O)}∞ (5), and {[Cd(ndc)(bpp)2](H2O)3}∞ (6) (ndc = naphthalene-2,3-dicarboxylate, 2bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline, 4bpy = 4,4′-bipyridine, abp = trans-4,4′-azobis(pyridine), and bpp = 1,3-bis(4-pyridyl) propane). The initial complex 1 shows a two-dimensional (2-D) (44.62) coordination network. 2 and 3 possess tetranuclear and one-dimensional (1-D) structures due to the incorporation of auxiliary chelating co-ligands 2bpy and phen, respectively, which are further interlinked via secondary interactions such as hydrogen bonding and aromatic stacking to result in higher-dimensional supramolecular networks. Whe...

Eight ZnII and CdII coordination complexes, {[Zn3(nbta)2(bpy)2(H2O)2](H2O)2}n (1), [Zn4(nbta)2(bpe)2(OH)2]n (2), {[Cd3(nbta)2(bpy)5(H2O)2](H2O)6}n (3), {[Cd3(nbta)2(bpe)2(H2O)2](H2O)2}n (4), [Zn2(Hbta)2(bpy)2(H2O)2](H2O) (5), [Zn(bta)(Hbpe)]n (6), [Cd5(bta)2(Hbta)2(bpy)3(H2O)2]n (7), and {[Cd4(bta)2(bpe)2(H2O)4(OH)2](H2O)2}n (8), were prepared via hydrothermal reactions based on H3nbta or H3bta (H3nbta = 5-nitro-1,2,3-benzenetricarboxylic acid and H3bta = 1,2,3-benzenetricarboxylic acid) and the dipyridyl-type coligand 4,4′-bipyridyl (bpy) or 1,2-di(4-pyridyl)ethene (bpe). All complexes were characterized by elemental analysis, IR spectra, and X-ray powder diffraction techniques. Complexes 1−4 all display unusual three-dimensional (3-D) self-penetrating coordination networks. From the topology point of view, complexes 1 and 2 display the 4-connected frameworks with the Schlafli symbols of (4.104.12)2(43.62.8)2(44.62) and (4.62.72.8)2(42.62.7.8), respectively. Complex 3 features an unprecedented 3-nodal ne...

A survey of the Cambridge Structural Database (CSD) indicates that 79% of complexes that contain both imidazole and carboxyl groups generate imidazolium-carboxylate supramolecular heterosynthons rather than carboxyl or imidazole supramolecular homosynthons. In the absence of other competing factors, the occurrence of such heterosynthons is increased to 100%. This observation is further supported by the crystal structures of seven new complexes that contain tris(2-benzimidazylmethyl)amine (TBMA) and a variety of carboxylic acids, including benzoic acid (HBA), p-methoxybenzoic acid (HPMBA), phthalic acid (H2PA), terephthalic acid (H2TPA), isophthalic acid (H2PIA), trimesic acid (H3TMA), and pyromellitic acid (H4PMA). In all seven complexes, (H2TBMA)·(BA)2·DMF (1), (HTBMA)·(PMBA)·(TBMA)·(HPMBA)2·2DMF·H2O (2), (HTBMA)·(H2TBMA)·(HPA)·(PA)·3DMF·H2O (3), (HTBMA)2·(TPA)·2DMF (4), (HTBMA)2·(PIA)·2DMF (5), (H2TBMA)·(HTMA)·0.5DMF·H2O (6), and (HTBMA)2·(H2PMA)·2DMF·H2O (7), proton transfer occurs from acid to aromati...

This work presents eight coordination assemblies based on divalent metal ions (M = CoII, CuII, ZnII, and CdII), dicyanamide anion (N(CN)2−, dca), and two isomeric bent dipyridyl coligands (L), namely, 2,5-bis(3-pyridyl)-1,3,4-oxadiazole (3-bpo) and 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (4-bpo). In the resulting crystalline materials, both bpo and dca tectons generally display the bidentate bridging fashion (except in the mononuclear species 5), extending the metal centers to afford diverse one-, two-, and three-dimensional (1-D, 2-D, and 3-D) coordination networks that are not commonly observed in M−dca−L systems. Notably, the inclined polycatenated 2-D → 3-D framework and 3-D polyknotting network with the unique 6-connected (44.611) topology are formed for the CuII and CdII species with dca and 4-bpo. For the polymeric CoII and CuII complexes, very weak antiferromagnetic or ferromagnetic interactions are observed between the metal centers due to the μ1,5-bridging mode of dca, and their magneto-structural c...

Five novel zinc(II) and cadmium(II) metal−organic coordination polymers with a tricarboxyl tecton and N-donor ancillary ligands, {[Zn(Hnbta)(2,2′-bipy)]·H2O}n (1), {[Cd3(nbta)2(2,2′-bipy)2(H2O)2]}n (2), {[Cd3(nbta)2(bpa)2]}n (3), {[Zn2(nbta)(OH)(bpa)1.5]·2H2O}n (4), and {[Zn3(nbta)2(bpp)2(H2O)2]}n (5) (H3nbta = 5-nitro-1,2,3-benzenetricarboxylic acid, 2,2′-bipy = 2,2′-bipyridine, bpa = 1,2-bi(4- pyridyl)ethane, and bpp = 1,3-bi(4-pyridyl)propane), have been prepared and characterized by elemental analysis, IR spectra, and X-ray diffraction. Complex 1 has a two-dimensional (2D) bilayer supramolecular network constructed from one-dimensional (1D) zigzag coordination chains via π···π interactions, whereas 2 exhibits a three-dimensional (3D) supramolecular network assembled from 1D coordination arrays through π···π interactions and weak C−H···O interactions. Complex 3 features a (4,5)-connected self-penetrating 3D coordination net with a (43·65·82)(43·62·8)(44·64·82)(45·65) topology. The 3D framework of 4 can...

A series of CdII, CoII, NiII, and PbII mixed-ligand coordination complexes 1−8 based on 5-sulfoisophthalic acid (H3sip) and the bent dipyridyl ligand 2,5-bis(3-pyridyl)-1,3,4-oxadiazole (3-bpo) or its 4-pyridyl N-donor analogue (4-bpo) have been synthesized and fully characterized by IR spectra, microanalyses, and single crystal and powder X-ray diffraction techniques. The significant pH effect on assembly of the CdII complexes 1−4 has been demonstrated, which leads to the formation of distinct crystalline products, whereas the CoII, NiII, and PbII systems 5−8 are independent to pH condition of the synthetic reaction. Complexes 1−8 display various coordination motifs with different existing forms, conformations, and coordination modes of the organic ligands. Further, extended supramolecular networks are constructed via secondary interactions such as hydrogen-bonding and aromatic stacking. Solid-state properties of thermal stability and fluorescence for these crystalline materials are also presented.

A unique self-penetrating coordination framework with (424.64) network topology is constructed from cage-shaped [Pb6(μ4-O)2(O2C)8] clusters as eight-connected nodes and long V-shaped dicarboxylate backbones as spacers, which interestingly can be regarded as the cross-linking of two interpenetrating six-connected pcu networks.

A series of silver(I) coordination polymers have been synthesized by the combination of an extended 2,4′-bipyridyl linker trans-1-(2-pyridyl)-2-(4-pyridyl)ethylene (bpe) and different benzenedicarboxyl tectons, including isophthalic acid (H2ip), 5-sulfoisophthalic acid (H3sip), terephthalic acid (H2tp), 2-aminoterephthalic acid (H2ata), and 2-bromoterephthalic acid (H2bta). Single-crystal X-ray diffraction indicates that the structural patterns of these polymeric complexes diversify from two-dimensional (2-D) (3,4,5)-connected (for 2) or 63 (for 3 and 4) layers to three-dimensional (3-D) (10,3)-b (for 1) or 8-nodal self-penetrating (for 5) networks. Interestingly, the AgI centers can show various coordination spheres such as linear, trigonal, tetrahedral, and square-pyramidal geometries. The results clearly reveal that the dicarboxyl building blocks with different dispositions of the carboxyl sites and uncoordinated substituent groups, are the crucial factors for structural assemblies of such extended fra...

A unique two-dimensional layer-based material [Cu(μ1,1-N3)2(H2O)][CuL2] (1, L = 2-methylpyrazine-5-carboxylate) was produced by a stepwise, microwave-assisted synthesis, featuring linear Cu(II)-μ1,...

Two related CoII 5-aminoisophthalate coordination frameworks [Co5(μ3−OH)2(5-NH2-bdc)4(H2O)2]·7.5H2O (1, 5-NH2-bdc = 5-aminoisophthalate) and [Co5(μ3−OH)2(5-NH2-bdc)4(bpy)0.5(H2O)]·3H2O (2, bpy = 4,4′-bipyridine) based on [Co5(μ3−OH)2] clusters have been synthesized by hydrothermal reaction, structurally described, as well as properties characterized, that have unusual 3D networks with high connectivity (3,12) and (3,13)-connected, respectively. Notably, the unique (3,13)-connected framework is constructed from the (3,12)-connected network analogue and 4,4′-bipyridyl spacer. Magnetic studies show that a dominant antiferromagnetic coupling between Co(II) ions, and the generation of relatively effective noncompensated moments at very low temperature, mainly arises from the cooperative magnetic effect of the intercluster arrangement in the Td−SP-3Oh mixed-geometry-based pentamer.

With solvent molecules participating in coordination systems, four new MnII coordination polymers of the rigid ligand 2,3,5,6-tetrachloro-1,4-benzenedicarboxylic acid (H2BDC-Cl4) have been obtained from different solvent media. Single-crystal X-ray analysis indicates that the coordination arrays of 1−4 vary from 1D fishbone or zigzag chain for 1 or 2, 2D (4,4) layer for 3, to 3D SrAl2 coordination network for 4, respectively. In {[Mn(BDC-Cl4)(py)2(H2O)2](py)2}n (1) and {[Mn(BDC-Cl4)(MeOH)3](MeOH)}n (2), pyridine/water (in 1) and MeOH (in 2) molecules act as the monodentate terminal ligands to fulfill the metal coordination spheres. In the case of {[Mn(BDC-Cl4)(dioxane)(H2O)2](dioxane)}n (3), the aqua ligand is monodentate and the dioxane moiety displays unusual bridging bidentate mode, whereas for [Mn5(BDC-Cl4)5(DMF)5]n (4), three MnII centers are connected by four BDC-Cl4 ligands and two DMF molecules to constitute a trimeric unit. These secondary units are extended to the final 3D network with SrAl2 (sr...

Three kinds of three-dimensional (3D) cadmium(II) pyridine-2,4,6-tricarboxylate (L) coordination polymers, L-[Cd(L)](NH2Me2) (1a), R-[Cd(L)](NH2Me2) (1b), [Cd3(L)2(H2O)4] (2), and [Cd4(L)2(OH)2(H2O...

Two derivative ligands of nicotinic or isonicotinic acid, namely, 2-(3-pyridyl)-4-methylthiazole-5-carboxylic acid (Hpmtca) and 2-(4-pyridyl)thiazole-4-carboxylic acid (Hptca), have been employed to assemble with a variety of divalent metal ions, leading to the generation of diverse metal−organic supramolecular architectures in different dimensions. Among them, complexes 1a and 1b, [Ni(pmtca)2(H2O)4]n, present a pair of conformational polymorphs with different neutral layered arrays, which are obtained from similar reaction conditions with NiII salts of different sources. [Cu(pmtca)2(H2O)]n (2) and [Zn(pmtca)2(H2O)]n (3) are isostructural two-dimensional (2-D) corrugated coordination networks. These layered patterns adopt interdigitated three-dimensional (3-D) crystalline packing and are further consolidated by hydrogen bonding, while [Co(pmtca)2(CH3CH2OH)2]n (4) shows a distinct one-dimensional (1-D) double chain structure. As for the CdII species, [Cd(pmtca)2(H2O)2]n (5) comprises a similar layered fram...

Two new flexible dipyridyl building blocks, N,N‘-bis(4-picolinoyl)hydrazine (4-bph) and its N-orientation isomer N,N‘-bis(3-picolinoyl)hydrazine (3-bph), have been synthesized as versatile cocrystallizing agents and introduced into the reactions with pyromellitic acid (H4BTA) and fumaric acid (H2Fa). Hydrogen-bonded directed assemblies of two hydrates of bphs and four binary cocrystals were validated by single-crystal X-ray diffraction analysis. With the presence of the reliable hydrogen-bonding donor/acceptor(s) of bph, the crystalline lattices of [4-bph]·2H2O (1) and [3-bph]·2H2O (4) are managed by N−H···Owater and O−H···Ocarbonyl to afford one-dimensional (1D) arrays, which are further extended to distinct three-dimensional (3D) (for 1) and two-dimensional (2D) (for 4) networks via O−H···Npyridyl interactions. While for the concomitant polymorphs [(H2BTA)·(H2-4-bph)] (2 and 3), charge-assistant bifurcated N−H···O bonds do favor 1D acid−base hydrogen-bonding tapes, which are interlinked to result in a 2...

A bent dipyridyl compound, 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (4-bpo), was employed to crystallize with 1,4-cyclohexanedicarboxylic acid (H2chdc), hydroquinone, citric acid (H4ca·H2O), barbituric acid, and ferrocene dicarboxylic acid (H2Fc) under general conditions, affording binary cocrystals [(H2chdc)·(4-bpo)] (1), [(hydroquinone)·(4-bpo)2] (2), [(H4ca)·(4-bpo)] (3), [(barbituric acid)·(4-bpo)] (4), and [(HFc)·(H-4-bpo)] (5) in high yield. X-ray single-crystal structures of these compounds reveal that a supramolecular synthon [ (7)] containing classical O−H···N and weak C−H···O interactions, usually observed in organic cocrystals of carboxylic acid and heterocyclic base, is again involved in constructing the hydrogen-bonding networks of 1, 3, and 5. Its ionic analogous synthon [consisting of strong N−H···O and weak C−H···O, (7)] also appears in the partly charge-transfer salt 5. For 2, only hydroxyl of the hydroquinone component can act as the hydrogen-bonding contributor, giving a strong O−H···N bond ...

Self-assembly of a flexible building unit 4-pyridylacetic acid (Hpya) with inorganic metal salts Cu(ClO4)2·6H2O, Co(OAc)2·4H2O, Ni(ClO4)2·4H2O, AgNO3, and HgCl2 affords five new metal−organic coordination frameworks [M(pya)2(H2O)2]n (pya = 4-pyridylacetate; M = Cu for 1; Co for 2; and Ni for 3), [Ag(pya)]n (4), and [Hg(pya)Cl]n (5) under similar reaction conditions. Single-crystal X-ray diffraction analyses of these polymeric complexes suggest that 1−3 are isostructural and exhibit a two-dimensional (2D) wavelike layered architecture constructed by alternate left- and right-hand helical chains, in which pya takes the bidentate (Npy, OCOO-) bridging mode. However, polymer 4 possesses a three-dimensional (3D) brickwall network generated from the expansion of 2D layers with dinuclear [Ag2(RCOO)2] nodes via further interlayer Ag−OCOO- interactions, which is also stabilized by argentophilic interactions (Ag···Ag = 2.983(3) A). The structure of 5 seems more complicated, in which the [Hg2(pya)2] boxlike dimeric ...

On the basis of the primary carboxyl/pyridyl hydrogen-bonded synthon, 2,5-bis(3-pyridyl)-1,3,4-oxadiazole (3-bpo) and its 4-N-donor isomer 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (4-bpo) were assembled with flexible dicarboxylic acids possessing variable chain lengths to afford a series of organic cocrystalline materials. [Fumaric acid]·[3-bpo] (1) has a two-dimensional (2-D) layered supramolecular pattern. [Fumaric acid]·[4-bpo] (2) has linear tapes connected via carboxyl/pyridyl heterosynthons and further creates a three-dimensional (3-D) square net with the CdSO4 topology combining with other weak interactions. [Suberic acid]·[3-bpo] (3), obtained in ambient conditions, exhibits a 3-D corrugated network; however, [suberic acid]·[4-bph] (4), produced unexpectedly by hydrothermal synthesis, displays a 3-D framework expanding from 2-D layers, in which N,N‘-bis(4-picolinoyl) hydrazine (4-bph) is generated in situ from the hydrolysis of 4-bpo. [Benzene-1,4-dioxyacetic acid]·[3-bpo] (5) takes on a nearly planar ...

Bent dipyridyl bases, 2,5-bis(3-pyridyl)-1,3,4-oxadiazole (3-bpo) and its 4-N-donor analogue 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (4-bpo), were applied to crystallize with trimesic acid (benzene-1,3,5-tricarboxylic acid, H3TMA) and pyromellitic acid (benzene-1,2,4,5-tetracarboxylic acid, H4BTA), affording new binary molecular cocrystals [(H3TMA)·(3-bpo)]·DMF (1), [(H3TMA)·(4-bpo)] (2), [(H4BTA)·(3-bpo)]·2H2O (3), and a partly charge-transfer salt [(H2BTA)1/2·(H-4-bpo)·(H4BTA)1/2]·H2O (4) under general conditions. An unexpected compound 5 (pyromellitic dihydrazide) was obtained during the attempt to attain a cocrystal of 4-bpo and H4BTA by hydrothermal synthesis. X-ray single-crystal diffraction studies reveal that supramolecular synthon I [ (7)] containing classical O−H···N and weak C−H···O interactions is again testified to be involved in constructing the binary hydrogen-bonding networks 1−4, in which the heteromeric intermolecular interactions are often utilized as effective synthetic tools to provide a ...

The high-yielding preparation and X-ray structures of six 1:1 molecular cocrystals consisting of bent dipyridyl bases and aromatic dicarboxylic acids, including [phthalic acid]·[3-bpo] (1), [phthalic acid]·[4-bpo] (2), [isophthalic acid]·[3-bpo] (3), [isophthalic acid]·[4-bpo] (4), [terephthalic acid]·[3-bpo] (5), and [terephthalic acid]·[4-bpo] (6), are described, in which 3-bpo refers to 2,5-bis(3-pyridyl)-1,3,4-oxadiazole and 4-bpo its 4-N-donor analogue 2,5-bis(4-pyridyl)-1,3,4-oxadiazole. A supramolecular synthon I [ (7)] containing classical O−H···N and weak C−H···O interactions, usually observed in organic cocrystals of carboxylic acids with other heterocyclic bases, is again shown to be involved in constructing most of these hydrogen-bonding networks. In compounds 3−5, tapes of acid/base components are formed via synthon I, which are further extended to result in two-dimensional (2-D) supramolecular sheets via additional C−H···O interactions. Compound 2 contains similar but helical tapes with synt...

A series of bis(arylthio)ethers, trans-1,4-bis(phenylthio)-2-butene (L1), trans-1,4-bis(2-pyridylthio)-2-butene (L2), trans-1,4-bis(2-pyrimidinylthio)-2-butene (L3), trans-1,4-bis(4-methyl-2-pyrimidinylthio)-2-butene (L4), and trans-1,4-bis(5-methyl-1,3,4-thiadiazolylthio)-2-butene (L5), have been designed and synthesized, and the reactions of these ligands with AgX salts (X = NO3-, ClO4-, or BF4-) lead to the formation of eight new metal−organic coordination polymers exhibiting from 1D to 3D frameworks. Single-crystal X-ray analysis showed that complexes 1, 2, and 4 exhibit 2D layer frameworks, and 3, 5, 6, and 8 have 1D chain structures, while 7 is a 3D coordination network. In these polymers, a variety of geometries of AgI and coordination modes of the organic ligands were observed due to the different numbers and relative orientation of N donors in the terminal groups of these ligands. In addition, the influences of counteranions and solvent coordination on the framework formations have been discussed...

Three-dimensional (3-D) metallo-supramolecular architectures 1−3 based on CuII−dca−cypy systems [dca = dicyanamide, N(CN)2-, and cypy = n-cyanopyridine (n = 4, 3, 2)], which are extended by combining metal-coordination and second-sphere hydrogen-bonded interactions, were rationally designed and structurally characterized by single-crystal X-ray diffraction. Reaction of CuII with dca and 4- or 3-cypy afforded two similar neutral one-dimensional (1-D) coordination polymers, [Cu(dca)2(4-cypy)2]n (1) and [Cu(dca)2(3-cypy)2]n (2), in which the octahedral CuII centers are linked through double μ1,5-dca bridges and the cypy moieties act as monodentate terminal ligands via their pyridyl nitrogen donors. The coordination chains of 1 and 2 are further cross-linked by C−H···N interactions between the free nitrile N atoms of cypy and H atoms of the pyridyl ring, creating two interpenetrating 3-D networks (for 2, further weaker hydrogen-bonding interactions between the amide N atoms of dca and the H atoms in 3-cypy co...

Coordination networks based on the organic ligand 2,5-bis(4-pyridyl)-1,3,4-thiadiazole (L1) or 2,5-bis(3-pyridyl)-1,3,4-oxadiazole (L2) and various inorganic silver(I) salts were prepared and chara...

Reaction of CdCl2·0.5H2O with 2,5-bis(4-pyridyl)-1,3,4-oxodiazole (bpo) and NH4SCN in a 1:1:2 molar ratio under CH3CN−H2O medium afforded a novel neutral three-dimensional (3D) coordination polymer {[Cd(bpo)(SCN)2]·CH3CN}n (1) [monoclinic, space group P21/c, a = 7.680(2) A, b = 10.029(3) A, c = 25.786(7) A, β = 93.779(5)°, Z = 4]. The crystal structure reveals that 1 has a 3D noninterpenetrating open framework with guest CH3CN molecules in the cavities, in which the CdII centers (with CdN4S2 octahedral geometry) are bridged by the bpo molecules and SCN- groups. It is interesting that the two-dimensional sheet in this 3D network consists of 16-membered [Cd4(μ-SCN-N,S)4] rings, and the bpo molecules extend these layers to a 3D structure, which is further stabilized by C−H···N hydrogen-bonding and strong π−π-stacking interactions. Thermogravimetric analysis and X-ray powder diffraction technique measurements illustrate that the framework of 1 is retained upon removal of the uncoordinated guest acetonitrile m...

A series of novel silver-thioether metal-organic supramolecular architectures forming different frameworks are constructed by the direct reactions of Ag I perchlorate with a series of di- or trithioether ligands which are closely related in structure. In the crystal structures of the four complexes, a variety of coordination modes of the Ag I centers due to the conformation freedom or steric hindrance have been observed, indicating that the nature of the ligands is a determining factor in controlling the structural topology of the metal-organic supramolecular architectures.