•Six hydrous 5-(3-pyridylmethoxy)isophthalate Cd(II) coordination polymers were prepared.•A little change of temperature or solvent can greatly affect their hydration and structures.•Two 2D double-layered networks and four 3D coordination polymers were constructed.•Coordination polymers exhibit high thermal stability and emit green luminescence.Six hydrous Cd(II) coordination polymers based on a scorpion-like 5-(3-pyridylmethoxy)isophthalic acid (H2L), namely {[CdL(H2O)]·2H2O}n (1), [Cd4L4(H2O)4]n (2), [CdL(H2O)]n (3), [CdL(H2O)2]n (4), {[CdL(H2O)]·H2O}n (5) and [CdL]n (6), were hydrothermally synthesized and characterized by EA, IR, PXRD, TG-DSC and X-ray structural analysis. Temperature and solvent play crucial roles in the preparation of the coordination polymers. Complexes 1–3 were prepared in a H2O-DMF (6:2) solvent system at slightly different temperature (85, 100 and 120 °C). Complexes 4–6 were prepared in different H2O-DMF solvents (6:3 and 8:2) and H2O-MeCN (3:6) solvent. These complexes possess different coordinated and/or lattice water molecules, and exhibit structural diversity and various topology nets. Complex 1 is a 2D double-layered coordination polymer. Complex 2 features a 3D porous framework with irl topology. Complex 3 displays a 2D double-layered network. Complex 4 is a 3D coordination polymer with sra topology. Complex 5 exhibits a 3D wave-like framework with sra topology. Complex 6 is a 3D coordination polymer with self-catenated hxg-d topology. 5-(3-Pyridylmethoxy)isophthalate adopts three types of coordination modes. These complexes exhibit higher thermal stability and emit strong luminescence.Six Cd(II) coordination polymers based on 5-(3-pyridylmethoxy)isophthalic acid were synthesized. These Cd(II) complexes possess different coordinated and/or lattice water molecules, and exhibit various structural features and topology nets. Temperature and solvent play crucial roles in the preparation reactions. A little change of temperature or solvent can greatly affect their hydration and structures. The coordination polymers exhibit high thermal stability and emit green luminescence.Download high-res image (120KB)Download full-size image

•Mixed-valence 1D ribbon coordination polymer [CuI2CuII(CN)2(PyHBIm)2Cl2]n is prepared.•XPS spectrum confirms the mixed-valence characteristics.•Cyanide originates from the in situ cleavage of acetonitrile.•Acetonitrile is an environmentally friend cyanating agent.Solvothermal reaction of CuCl2·2H2O and 2-(4-pyridyl)benzimidazole (PyHBIm) in a acetonitrile-water mixed solvent afforded a mixture of [CuI2CuII(CN)2(PyHBIm)2Cl2]n (1) and [CuII(PyH2BIm)2Cl4] (2). Complex 1 is a mixed-valence 1D ribbon Cu(I,II)-cyanide coordination polymer. One Cu(II) center linearly links two Cu(I) ions via two μ2-CN bridges. XPS spectrum and bond valence sum (BVS) analysis have confirmed the mixed-valence characteristics. Cu(II) ion adopts a centrosymmetric square-planar geometry surrounded by two cyanides and two pyridyl groups. Cu(I) ions adopt a trigonal geometry coordinated by cyanide, imidazole group and Cl− anion. The cyanide ligand is in situ generated from the cleavage of acetonitrile solvent, which indicates that acetonitrile is an environmentally friend cyanating agent. The mechanism of acetonitrile in situ cleavage under solvothermal condition is explained. Complex 2 is a centrosymmetric mononuclear Cu(II) compound. Four equivalent Cl− anions lie on the equatorial plane. The protonated PyH2BIm+ cation as a monodentate ligand coordinates to Cu(II) center via pyridyl terminal.One mixed-valence [CuI2CuII(CN)2(PyHBIm)2Cl2]n complex is prepared. XPS spectrum and BVS analysis confirm the mixed-valence characteristics. Cyanide originates from the in situ cleavage of acetonitrile. The mechanism of acetonitrile cleavage is explained.Download high-res image (244KB)Download full-size image

•Three copper(I) cyanide coordination polymers incorporating N-donor ligands were prepared.•[Cu8(CN)8(btmb)2]n (1) is a 2D double-layered network containing eight distinct Cu(I) centers.•These copper(I) complexes emit blue luminescence.Three copper(I) cyanide coordination polymers, namely [Cu8(CN)8(btmb)2]n (1), [Cu(CN)(btmb)0.5]n (2) and [Cu2(CN)2(dpa)]n (3) (btmb = 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene, dpa = di(4-pyridyl)amine), were synthesized under hydrothermal conditions and characterized by elemental analyses, IR spectra, PXRD and thermogravimetric analyses. Single-crystal X-ray diffraction analyses reveal that complex 1 is an interesting 2D double-layered network constructing from eight distinct Cu(I) centers, eight μ2-cyanides and two tetradentate cis-btmb ligands. Complex 2 is a ladder-like coordination polymer assembled by CuCN linear chain and bidentate trans-btmb linker. Complex 3 has a 2D wave-like network constructing from CuCN zigzag chain and V-shape dpa spacer. These coordination polymers are thermally stable up to 270–300 °C. They emit blue luminescence originating from ligand-centered emission.Three copper(I) cyanide coordination polymers were constructed based on two flexible N-heterocyclic ligands. [Cu8(CN)8(btmb)2]n (1) is a 2D double-layered network containing eight distinct Cu(I) centers and eight μ2-cyanides. Complex 2 shows a ladder-like chain structure, while complex 3 exhibits a 2D wave-like network. These Cu(I) complexes are stable up to 270–300 °C and emit blue luminescence.Download high-res image (208KB)Download full-size image

Metal salts and 3/4-pyridyltetrazoles (3/4-Hptz) react with oxalic acid (H2ox), 1,2,4,5-benzenetetracarboxylic acid (H4btec), isophthalic acid (H2ip), and 1,2,3,4-butanetetracarboxylic acid (H4btca) to afford six coordination polymers, namely, [Cu(4-ptz)(ox)0.5]n (1), [Cu(4-Hptz)(btec)0.5]n (2), [Co2(3-ptz)(ip)(OH)(H2O)]n (3), {[Co1.5(3-ptz)(btca)0.5(H2O)]·H2O}n (4), {[Co3(4-ptz)2(btca)(H2O)3]·2H2O}n (5), and {[Cd2(4-ptz)2(btca)0.5(H2O)3]·DMF·4H2O}n (6). Their structures were characterized by EA, IR, PXRD, TGA, and single-crystal XRD. 3/4-Pyridyltetrazoles display μ2-, μ3-, and μ5-coordination modes in them. Complex 1 is a 3D MOF constructed from a 2D (4,4) [Cu(4-ptz)]n grid pillared by an oxalate spacer. Complex 2 displays a 2D network containing a square planar Cu1 and elongated octahedral Cu2 centers. Complex 3 shows a 2D network containing μ5-ptz, μ3-ip, and μ3-OH. Complex 4 exhibits a 3D MOF assembled by a 2D [Co1.5(btca)0.5]n network pillared by a 3-ptz spacer. Complex 5 displays a 3D porous MOF with nanosized rectangular tunnels. Complex 6 features a 3D porous MOF built by 2D [Cd2(4-ptz)(btca)0.5]n network pillared by a 4-ptz spacer. Variable-temperature magnetic susceptibility and magneto-structural correlation studies indicate that five CuII/CoII complexes present remarkable magnetic coupling diversity from ferro-, to ferri-, to antiferromagnetic interactions. Complex 1 shows strong antiferromagnetic behavior originating from the oxalate-bridging CuII dimer (Jox = −94.7 cm–1) and the tetrazole-bridging CuII dimer (Jptz = −61.0 cm–1). Complex 2 presents a weak ferromagnetic interaction (J = 0.82 cm–1) originating from the magnetic orbital orthogonality between square planar CuII and octahedral CuII centers. Complex 3 displays ferrimagnetic coupling in the Co3(μ3-OH) triangle. Two btca CoII complexes show antiferromagnetic interactions originating from carboxyl-bridging trinuclear CoII clusters with the θ values of −17.08 K for 4 and −8.6 K for 5. The thermal behaviors of these nitrogen-rich tetrazole complexes are investigated. Anhydrous complexes 1–3 containing rigid polycarboxylates are thermally stable to 250–300 °C and then decompose explosively, whereas complexes 4–6 with flexible butanetetracarboxylate decompose smoothly.

Seven novel coordination polymers based on 2,2′-phosphinico-dibenzoic acid (H3L), namely, {[Zn3L2(H2O)4]·2H2O}n (1), [Zn3L2(4,4′-bipy)2]n (2), [Zn(HL)(2,2′-bipy)(H2O)]n (3), {[Cd9L6(H2O)8]·4H2O}n (4), [Cd8L4(OH)2(OAc)2(4,4′-bipy)]n (5), [Mn3L2(4,4′-bipy)(EtOH)(H2O)2]n (6), and [Mn(HL)(2,2′-bipy)(H2O)]n (7), were synthesized under hydro(solvo)thermal conditions. These compounds crystallize in the triclinic P1̅ space group for 1, 4, 5, and 6, the monoclinic space group C2/c for 2, and the monoclinic P21/c space group for 3 and 7. The L3– ligand displays versatile binding modes in 1–7. Compound 1 is a one-dimensional (1-D) chain coordination polymer with a three-dimensional (3-D) supramolecular framework. Compound 2 is a 3-D porous metal–organic framework (MOF) with two different 4,4′-bipyridine linkers. Compounds 3 and 7 show 1-D zigzag chain structures. Compound 4 exhibits a sophisticated 3-D MOF constructed from two types of Cd8 clusters and one Cd2 dimer, which is the first example exhibiting the coexistence of four coordination modes of L3– ligands and four geometries of Cd(II) ions in one network. Compound 5 displays a two-dimensional (2-D) network containing a ring-like Cd8 cluster. Compound 6 shows a 2-D layered network with 4,4′-bipyridine linker. Their luminescence and variable-temperature magnetic property were investigated, which indicated ligand-centered emission in 1–5 and weak antiferromagnetic coupling between Mn(II) ions in 6 and 7.

•Six Zn(II)/Cd(II) coordination polymers were prepared.•The coordination polymers display different topological network.•5-(3-Pyridylmethoxy)isophthalate exhibit five types of coordination modes.•The complexes are quite thermally stable and emit blue luminescence.Six coordination polymers based on 5-(3-pyridylmethoxy)isophthalic acid (H2L), namely [Zn2L2]n (1), [Zn2L2(1,3-bix)]n (2), [CdL(1,3-bix)]n·2nH2O (3), [CdL(azpy)0.5(H2O)]n (4), [CdL(btx)0.5]n (5), and [CdL(btmb)]n·2nH2O (6) (1,3-bix = 1,3-bis(imidazol-1-ylmethyl)benzene, azpy = 4,4′-azobispyridine, btx = 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene, btmb = 4,4′-bis(1,2,4-triazol-1-ylmethyl)biphenyl), have been synthesized and characterized by elemental analyses, IR spectra, PXRD, thermogravimetry and X-ray structural analysis. Complex 1 is a 3D coordination polymer, simplified as a 4-nodal (4,4,5,5)-connected topology net with point symbol {43.63}{43.62.8}{44.65.8}{44.64.82}. Complex 2 is a 3D coordination polymer, simplified as a crs-d topology net with point symbol {6;82}{62;83;10}. Complex 3 is a 2D coordination polymer with a 2-nodal (3,5)-connected topology net. Complex 4 exhibits a 2D double-layered network with a 2-nodal (3,4)-connected topology net, assembled by two parallel [CdL]n layers pillared by azpy spacer. Complex 5 is a 3D coordination polymer, simplified as a 2-nodal (3,8)-connected topology net with point symbol {43}2{46.618.84}. Complex 6 shows a 2D double-layered network with a 2-nodal (3,5)-connected topology net, constructed from wave-like [CdL]n network pillared by btmb spacer. 5-(3-Pyridylmethoxy)isophthalate exhibits five types of coordination modes. Anhydrous or dehydrated substances of 1–6 were thermally stable to 300–400 °C. These Zn(II)/Cd(II) complexes emit blue luminescence originating from ligand-centered emission.Six 5-(3-pyridylmethoxy)isophthalate Zn(II)/Cd(II) coordination polymers were prepared and structurally characterized. 5-(3-Pyridylmethoxy)isophthalate exhibits five types of coordination modes in them. Complexes 1, 2 and 5 are 3D coordination polymer with different topology nets. Complexes 3, 4 and 6 are 2D coordination polymers with different structures. Their anhydrous frameworks are quite thermally stable. The complexes emit blue luminescence originating from ligand-centered emission.

•Four new Zn (II) coordination polymers have been synthesized and characterized.•The size of solvent molecular may as template to make more porosity for assembling structure.•The solvent effects play an important role for design these compounds.Four unique complexes with diverse coordination architectures were synthesized upon complexation of 5,5-(1,4-phenylenebis (methylene))bis (oxy)- diisophthalic acid (H4L) with zinc ions by using different solvent. namely, {[Zn(H2L) (bpp)]·DEF}n (1), {[Zn2(L) (bpp)2]·4H2O}n (2), {[Zn2(L) (pdp)2]·3H2O·DEF}n (3), {[Zn2(L) (pdp)2].4H2O}n (4). Complexes 1,2 and 3,4 are obtained by varying solvents to control their structures. The size of solvent molecular plays an important role to control different structure of these compounds. Compound 1 is 2D waved framework with (4, 4) grid layer as sql topology. Compound 3 displays a (4,6)-connected 2-nodal net with a fsc topology. Compounds 2 and 4 are all three-dimensional network simplified as (4,4)-connected 2-nodal net with a bbf topology. The photochemical properties of compounds 1–4 were tested in the solid state at room temperature, owing to their strong luminescent emissions, complexes 1–4 are good candidates for photoactive materials.

•Eight isostructural lanthanide coordination polymers were prepared.•The 3D MOFs display (4,5)-connected tcs topological network.•5-(3-Pyridylmethoxy)isophthalate coordinates four Ln3+ ions via two bridging carboxyl groups.•Eu3+ and Tb3+ complexes emit strong red and green luminescences.Eight new lanthanide coordination polymers, {[LnL(Bdc)0.5(H2O)2]·H2O}n [Ln = Ce(1), Pr(2), Nd(3), Sm(4), Eu(5), Gd(6), Tb(7), Dy(8)] (H2L = 5-(3-pyridylmethoxy)isophthalic acid, H2Bdc = terephthalic acid), have been hydrothermally synthesized and structurally characterized by elemental analyses, IR spectra, PXRD and single crystal X-ray diffraction. Complexes 1–8 display isostructural 3D metal-organic frameworks (MOFs) constructed from 2D [LnL(H2O)2]n networks pillared by Bdc2− spacers. Tetradentate 5-(3-pyridylmethoxy)isophthalate ligand coordinates four Ln(III) ions via two bridging carboxyl groups. The 3D MOFs can be simplified as a (4,5)-connected tcs topological network with the Schläfli notation of {44.62}{44.66}. Thermal stabilities (TG-DSC) of these complexes are determined. Eu(5) and Tb(7) complexes emitting strong red and green luminescences demonstrate that the ligand-to-lanthanide energy transfer is efficient.Eight lanthanide coordination polymers, {[LnL(Bdc)0.5(H2O)2]·H2O}n [Ln = Ce(1), Pr(2), Nd(3), Sm(4), Eu(5), Gd(6), Tb(7), Dy(8)], were prepared with 5-(3-pyridylmethoxy)isophthalate and terephthalate ligands. These complexes are isostructural 3D MOFs and display (4,5)-connected tcs topological network. The 5-(3-pyridylmethoxy)isophthalate ligand coordinates four Ln3+ ions via two bridging carboxyl groups. Eu3+ and Tb3+ complexes emitting strong red and green luminescences demonstrate that the ligand-to-lanthanide energy transfer is efficient.

Six zinc metal–organic frameworks, namely, [Zn(bpmb)(HCOO)]n·[Zn(bpmb)(OH)]n·4nH2O (1), [Zn(bpmb)(HCOO)]n (2), [Zn2(bpmb)2(fum)]n·9nH2O (3), [Zn3(bpmb)2(d-cam)2]n (4), [Zn2(bpmb)(1,3,5-btc)]n·nDMA (5), and [Zn(bpmb)(1,2,4,5-H2btec)]n·4nH2O (6) (Hbpmb = 3,5-bis(4-pyridylmethoxy)benzoic acid; H2fum = fumaric acid; d-H2cam = d-camphoric acid; 1,3,5-H3btc = 1,3,5-benzenetricarboxylic acid; 1,2,4,5-H4btec = 1,2,4,5-benzenetetracarboxylic acid; DMA = N,N-dimethylacetamide), were synthesized under solvothermal conditions. Their structures were characterized by EA, IR, PXRD, TG, and single-crystal XRD. Complex 1 is constructed of two independent neutral 3D MOFs with large 1D nanosized square channels, which are further entangled by each other to give an unexpected 4-fold [2 + 2] interpenetrating architecture. Complex 2 is a 3D MOF constructed from tetradentate bpmb and bidentate formate ligands, which is an isomer of the [Zn(bpmb)(HCOO)]n piece in 1. Complex 3 displays a 2D double-layered network that possesses 1D nanosized pores. Each 2D double layer is further interlocked with two neighboring ones to form an interesting 3D polycatenation array. Complex 4 possesses a 2D network constructed from a trinuclear [Zn3(COO)6N4] cluster and Zn–cam double-helical chain. Complex 5 is a 3D porous MOF constructed from tridentate bpmb and hexadentate 1,3,5-btc ligands. Complex 6 exhibits a 2-fold interpenetrating 2D wavelike (4,4) network constructed from bidentate bpmb and 1,2,4,5-H2btec ligands. The bpmb ligand adopts four types of coordination modes in 1–6. The secondary carboxylate ligands have obvious effects on their coordination architectures. Tetrahedral-, octahedral-, and trigonal-bipyramidal geometries around Zn(II) ions are observed. A general solvothermal method is proposed for preparing carboxylate complexes in DMF−H2O solution without any basic additive. In the preparation of 3, maleic acid is converted to a fumarate ligand. The thermal stabilities of six complexes and N2 adsorption behaviors of 1 and 3 are investigated. All the Zn(II) complexes emit blue luminescence originating from ligand-centered emission.

Eight coordination polymers based on H4L1/H4L2 (5,5′-(1,4/1,3-phenylenebis(methoxy))diisophthalic acid) and 3/4-abpt (4-amino-3,5-bis(3/4-pyridyl)-1,2,4-triazole) ligands were synthesized: [Co4(L1)2(4-abpt)(H2O)10.5]n (1), {[Zn2(L1)(4-abpt)(H2O)3]·5H2O}n (2), {[Co(H2L1)(3-abpt)(H2O)2]·0.5H4L1}n (3), {[Co2(L1)(4-abpt)2]·4H2O}n (4), {[Zn2(L2)(4-abpt)(H2O)]·2.5H2O}n (5), {[Zn2(L2)(4-abpt)(H2O)]·3H2O}n (6), {[Co1.5(HL2)(3-abpt)(H2O)]·H2O}n (7), and {[Zn1.5(HL2)(3-abpt)(H2O)]·H2O}n (8). Their structures were characterized by EA, IR, powder X-ray diffraction, thermogravimetric analysis (TGA), and single crystal X-ray diffraction. Complex 1 exhibits a three-dimensional (3D) metal–organic framework (MOF) composed of an interesting tetranuclear Co4(μ2-H2O)3(μ2-COO)4 cluster and 76-membered ring. Complex 2 shows a two-dimensional (2D) sheetlike network assembled by a one-dimensional (1D) [Zn2(L1)(H2O)3]n ribbon and 4-abpt linker. Complex 3 is a 1D nanotube coordination polymer constructed from parallel Co2(H2L1)2 rings pillared by two rows of 3-abpt spacers, which contains H4L1 guest molecule. Complex 4 displays a beautiful 3D porous MOF built by 2D sheetlike [Co2(L1)]n networks pillared by 4-abpt spacers. Complex 5 features a porous 3D MOF with regular nanosized rectangle tunnel. Complex 6 exhibits a 3D structure constructed from a double-layered [Zn2(L2)(H2O)]n network and 4-abpt linker. Complexes 7 and 8 are isostructural 3D polymers completed by 2D [Co1.5/Zn1.5(HL2)(H2O)]n networks pillared by 3-abpt spacers. H4L1 and H4L2 are fully or partly deprotonated in these complexes and exhibit six types of coordination modes. The 3/4-abpt ligands act as bidentate linkers. TGA shows that both tetracarboxylates ligands are thermally stable to 300 °C. Zn(II) complexes 2 and 8 are strong luminescent emitters. Variable-temperature magnetic studies indicate that complexes 1, 4, and 7 exhibit antiferromagnetic coupling between carboxyl-bridging CoII ions.

•Two 1D 4-cptpy coordination polymers were prepared.•Complex 1 displays 3D supramolecular framework in which 4-cptpy exists as a guest.•Complex 2 is a linear chain coordination polymer with quadrangled pores.•Complex 1 exhibits an antiferromagnetic interaction in (μ-O2CR)2Mn2 core.MnII and CoII salts reacting with 4-(4-carboxyphenyl)-4,2′:6′,4″-terpyridine (4-Hcptpy) in DMF/H2O afford two complexes, [Mn(4-cptpy)(DMF)(H2O)2]n·n(4-cptpy)·nDMF (1) and [Co(4-cptpy)2(H2O)2]n (2). Complex 1 is a 1D ribbon coordination polymer assembled by Mn2 dimer and tridentate 4-cptpy ligand. The guest 4-cptpy anion is embedded in 3D supramolecular architecture with strong hydrogen bonds. Complex 2 is a 1D linear chain coordination polymer with quadrangled pores. The complex 1 releases H2O and DMF in 87–150 °C, and the anhydrous [Mn(4-cptpy)]n·n(4-cptpy) remains thermally stable until 403 °C. Variable temperature magnetic susceptibility study in 2–300 K proves that a weak antiferromagnetic interaction exists in the (μ-O2CR)2Mn2 core.Two MnII/CoII 1D coordination polymers were constructed from 4-(4-carboxyphenyl)-4,2′:6′,4″-terpyridine. [Mn(4-cptpy)(DMF)(H2O)2]n·n(4-cptpy)·nDMF displays interesting supramolecular framework in which uncoordinated 4-cptpy exists as guest molecule. Its magnetic properties and thermal stability have been studied.

•Six 3-(4-hydroxypyridinium-1-yl)phthalate coordination polymers were prepared.•Complex 4 exhibits a 1D nano-tubular structure with larger cavity occupied by (H2O)5 cluster.•Four typical coordination modes of 3-(4-hydroxypyridinium-1-yl)phthalate are observed.•Complexes 1 and 3 exhibit blue luminescence.Hydro(solvo)thermal reactions of metal salts and 3-(4-hydroxypyridinium-1-yl)phthalic acid (H2L) with 4,4′-bipyridine (4,4′-bipy), N,N′-bis(4-pyridylmethyl)piperazine (4-bpmp), and 1,3-bis(4-pyridyl)propane (bpp) auxiliary dipyridyl ligands afforded six new coordination polymers, namely [CdL(H2O)]n (1), [CoL(4,4’-bipy)0.5(H2O)]n (2), [ZnL(4-bpmp)0.5(H2O)]n·2nH2O (3), [ZnL(bpp)]n·5nH2O (4), [Zn2L2(bpp)(H2O)2]n·nH2O (5) and [Zn2L2(bpp)(H2O)]n·4nH2O (6). They were characterized by elemental analysis, IR, PXRD, thermogravimetry and X-ray structural analysis. Complex 1 is a 1D ribbon coordination polymer. Complex 2 is a 2D coordination polymer constructed from L and 4,4′-bipy ligands, which is further extended into a 3D supramolecular framework through strong hydrogen bonds. Complex 3 features a 1D chain polymeric structure formed by [Zn2L2] dimer and 4-bpmp linker. Complex 4 exhibits a 1D nano-tubular structure with larger cavities, which are fully occupied by (H2O)5 clusters. Complex 5 displays a 1D linear chain structure. Complex 6 is a 2D layered coordination polymer. These complexes exhibit structural diversity originating from four typical coordination modes of 3-(4-hydroxypyridinium-1-yl)phthalate and various dipyridyl spacers. Thermogravimetric analyses demonstrate that the dehydrate complexes are thermally stable to ca. 260–300 °C. Complexes 1 and 3 emit strong blue luminescence originating from ligand-centered emission.Graphical abstractSix coordination polymers were prepared with 3-(4-hydroxypyridinium-1-yl)phthalate primary ligand which displays four typical coordination modes. [ZnL(bpp)]n·5nH2O (4) exhibits a 1D nano-tubular structure with larger cavity occupied by (H2O)5 cluster. The dehydrate coordination polymers are thermally stable to ca. 260–300 °C. Complexes 1 and 3 emit strong blue luminescence originating from ligand-centered emission.

Six new coordination polymers, namely, [Cd(SO4)(4-abpt)(H2O)]n·3nH2O (1), [Cu3(CN)3(4-abpt)2]n (2), [Cd(D-cam)(2-PyBIm)(H2O)]n (3), [Co(D-Hcam)(cptpy)]n (4), [Cd(D-cam)(btmb)]n (5), and [Cd2(D-cam)(L-cam)(btmbb)]n (6) (4-abpt = 4-amino-3,5-bis(4-pyridyl)-1,2,4-triazole, D-H2cam = d-camphoric acid, 2-PyBIm = 2-(2-pyridyl)benzimidazole, Hcptpy = 4′-(4-carboxyphenyl)-3,2′:6′,3″-terpyridine, btmb = 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene, btmbb = 4,4′-bis(1,2,4-triazol-1-ylmethyl)-1,1′-biphenyl), have been synthesized under hydro(solvo)thermal conditions. Their structures were determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, infrared spectra, powder X-ray diffraction, circular dichroism, and thermogravimetric analysis. Complex 1 features a 3D porous metal–organic framework, which is a rare example to obtain a homochiral compound from achiral components. Complex 2 exhibits a 2D polymeric network constructed from μ2-cyanide, μ2-4-abpt, and monodentate 4-abpt ligands. Complex 3 is a homochiral 1D helical chain polymer. Complex 4 displays a 1D ladder-like polymeric structure in which cptpy– is tetradentate and D-Hcam– acts as a side arm. Complex 5 displays a homochiral 2D network with (4,4) topology. Complex 6 shows a [Cd2(D-cam)(L-cam)]n (4,4)-connected network with a paddle-wheel Cd2(COO)4 as node, which is further pillared by a btmbb spacer into a 3D metal–organic framework. d-Camphoric acid underwent racemization under hydrothermal conditions. Cd(II) complexes 1, 3, and 5 crystallize in chiral space groups, and their circular dichroism spectra exhibit obvious positive or negative Cotton effects. Moreover, 1, 3, and 5 are SHG-active, and the SHG efficiency, respectively, is 0.15, 0.4, and 0.4 times as much as that of KH2PO4. All the complexes exhibit relatively high thermal stability. 1, 3, 5, and 6 emit violet luminescence originating from ligand-centered emission.

Six complexes based on a new rigid V-shaped ligand, 2,6-bis(3-(pyrid-4-yl)-1,2,4-triazolyl)pyridine (2,6-H2bptp), namely, [Cd4(2,6-bptp)2(d-cam)(l-cam)(H2O)2]n·4nH2O (1), [Cd2(2,6-Hbptp)2(Hbtc)]n·4nH2O (2), [Zn(2,6-bptp)(H2O)]n·nH2O (3), [(Mo8O26)Cu2(2,6-H2bptp)2]n (4), [Co(2,6-H2bptp)2][Mo8O26]0.5·5H2O (5), and [(PMo12O40)Ag(2,6-H4bptp)]·2H2O (6) (d/l-H2cam = d/l-camphoric acid; H3btc = 1,3,5-benzenetricarboxylic acid), have been synthesized under hydrothermal conditions. Among these complexes, 2,6-H2bptp adopts seven types of coordination modes; all display a central tridentate chelating plane. Complex 1 possesses a 3D porous metal–organic framework that exhibits an intriguing sandwich-like motif. Complex 2 is a 1D nanorod-like coordination polymer with a square section of 1.11 × 1.06 nm2. Complex 3 exhibits a 1D zigzag chain structure, which is extended to a supramolecular double-chain by hydrogen bonding. In complex 4, polyoxometalate β-Mo8O264– links Cu2(2,6-H2bptp)24+ dimer to form a 1D linear chain polymer. Complex 5 displays a 3D supramolecular architecture with nanosized tunnels in which β-[Mo8O26]4– clusters embed. Complex 6 is a mononuclear silver complex constructed from Ag(2,6-H4bptp)3+ and [PMo12O40]3– pieces, which is further extended to a 3D supramolecular framework. The metal–organic frameworks of 1 and 2 are thermally stable up to 440 °C. Both Cd(II) complexes emit blue luminescence originating from ligand-centered emission. Complex 4 shows weak antiferromagnetic coupling in the Cu2(2,6-H2bptp)24+ dimer.

Reactions of zinc ions with the flexible tetracarboxylate ligand, 5,5′-(1,4-phenylenebis(methylene))bis(oxy)diisophthalic acid (H4L1) gave rise to ten complexes, namely {[Zn3(L1)(OH)2(H2O)2]3H2O}n (1), {[Zn(H2L1)(H2O)2]H2O}n (2), [Zn2(L1)(H2O)4]n (3), {[Zn2(H3L1)2(H2L1)(H2O)2(MeCN)2]}n (4), [Zn2(H3L1)2(H2L1)(2,2′-bipy)2]n (5), [Zn2(H3L1)2(H2L1)(1,10-phen)2]n (6), {[Zn2(L1)(4,4′-bipy)2]4H2O}n (7), {[Zn2(L1)(bpe)2]4H2O}n (bpe = 1,2-bi(4-pyridyl)ethene) (8), {[Zn2(L1)(pdp)2]4H2O}n (pdp = 4-[(E)-4-Pyridinylazo]pyridine) (9) and {[Zn2(L1)(bpmp)2]6H2O}n (bpmp = N,N′-bis-(4-pyridyl-methyl) piperazine) (10). The H4L1 ligand not only displayed different deprotonated forms, but also diverse coordination modes and conformations. Compounds 1–4 are constructed of only zinc atoms with H4L1 ligands while compounds 5–10 are constructed of zinc atoms and H4L1 ligands with various N-donor ligands (Scheme 1). Compound 1 features a 3D architecture constructed of a linear Zn3 cluster with H4L1 ligands. Compound 2 is a 2D waved layer structure with (4,4) grid as sql topology. Compound 3 displays a three-dimensional (3D) network simplified by a (3,6)-connected 2-nodal net with ant topology. Compounds 4, 5 and 6 all exhibit 1D infinite chains coordination structure, in which the H4L1 ligand is displayed as two kinds of deprotonated forms. Compounds 7, 8, 9 and 10 are similar and possess (4,4)-connected 3D frameworks with bbf topology, while also exhibiting an intriguing three-fold interpenetrated structure. These results indicate that subtle environmental factors, such as solvent, pH value and neutral auxiliary ligands play important roles in the formation of the structures of the final framework. At the same time, the photochemical properties of compounds 1–10 were tested in the solid state at room temperature, and the luminescent properties of compound 9 and 10 when dispersed in different solvents were investigated. These showed solvent-dependent luminescent spectra with emission intensities significantly quenched towards nitrobenzene. The quenching effects are observed at a low nitrobenzene concentration of 200 ppm, which indicates high sensitivities of these compounds towards nitrobenzene.

•Three camphorate coordination polymers were prepared.•Complex 1 is a chiral 1D helical chain polymer and 2 exhibits a chiral 2D network.•Complex 3 is an achiral 2D polymer in which partial d-camphorate changes to l-camphorate.•Complexes 1 and 2 show violet luminescence, 3 exhibits an antiferromagnetic interaction.Hydrothermal reactions of d-(+)-camphoric acid (d-H2cam) and 5,6-dimethylbenzimidazole (dmbi) with metal salts afforded three coordination polymers, namely [Cd2(d-cam)2(dmbi)4]n (1), [Zn2(d-cam)2(dmbi)2]n (2) and [Co(d-cam)1/2(l-cam)1/2(dmbi)]n (3), which were characterized by elemental analysis, IR, PXRD, CD, thermogravimetry and X-ray structural analysis. Complexes 1 and 2 are homochiral coordination polymers. 1 is a 1D left-handed helical chain coordination polymer constructed from tri- and tetra-dentate camphorate. 2 exhibits a 2D polymeric network assembled by tri-dentate camphorate, which belongs to 3-connected {4.82} topology. 3 is a 2D achiral coordination polymer assembled by left- and right-handed 1D Co-camphorate helical chains. It is rarely observed that d-cam ligand changes to l-cam under hydrothermal condition. Three complexes are all thermally stable up to 316–425 °C. 1 and 2 show violet luminescence originating from ligand-centered emission. 3 exhibits an antiferromagnetic interaction in CoII2 dimer with J = −4.34 cm−1.Three camphorate coordination polymers were prepared with 5,6-dmbi auxiliary ligand. 1 displays a 1D helical chain structure. 2 exhibits a 2D chiral network with 3-connected {4.82} topology. 3 is a 2D achiral polymer assembled from d-cam and l-cam ligands. They are all thermally stable up to 316–425 °C. 1 and 2 show violet luminescence. 3 displays an antiferromagnetic interaction.

Two homochiral coordination polymers [Mn2(D-cam)2(2-Hpao)4]n (1) and [Co2(D-cam)2(3-abpt)2(H2O)3]n·5nH2O (2) were prepared with D-(+)-camphoric acid, and 1-D complex 1 featured good temperature-independent piezoelectric (6.9 pC N−1) and dielectric properties.

Five novel hybrid compounds, [Mo8O26Cu2(4-abpt)2]n·4nH2O (1), (4-H2abpt)2[Mo8O26] (2), [Mo8O26Cu2(3-abpt)2(H2O)2]n (3), [MoO4Cu(3-abpt)(H2O)]n (4), and [Mo6O19Co(3-abpt)2]n·4nH2O (5) were prepared by reacting MoO3/(NH4)6Mo7O24 with 4-amino-3,5-bis(3/4-pyridyl)-1,2,4-triazole (3/4-abpt) and corresponding metal salts. Compound 1 is a 2D coordination polymer containing extended γ-[Mo8O26]4− and [Cu2(4-abpt)2]4+ ribbons. Compound 2 is a supramolecular hybrid aggregate composed of H-bond linking β-[Mo8O26]4− and 4-H2abpt2+. Compound 3 exhibits a 2D rectangular network constructed by isolated β-[Mo8O26]4−clusters and [Cu2(3-abpt)2]4+. In compound 4, each MoO42− anion links two Cu(II) ions to form a S-type [CuMoO4]n chain, which is further linked by bidentate 3-abpt to form a 2D wave-like network. In complex 5, unprecedented cyclic [Mo6O19]2−cluster links two neighbouring hexamolybdates and two Co(II) ions to form a 2D [CoMo6O19]n network, which is further pillared by tetradentate 3-abpt to generate a 3D metal–organic framework. These compounds are thermally stable under 250 °C. The composites of the final residues were analyzed by PXRD.

Hydrothermal reaction of Ln(NO3)·6H2O with benzimidazole-5,6-dicarboxylic acid (H3bidc) and KSCN afforded a series of new two- and three-dimensional coordination polymers, namely [Ln2(Hbidc)2(SO4)(H2O)3]n (Ln = La (1), Pr (2), Sm (3), Gd (4)) and [Ln4(Hbidc)4(SO4)2]n·2nH2O (Ln = Eu (5), Tb (6), Dy (7), Er (8)). The sulfates were in situ generated by catalytic oxidation of KSCN. These complexes were characterized by single crystal X-ray diffraction, IR spectroscopy, thermal analysis, fluorescent spectra and magnetic measurements. Complexes 1–4 are isomorphous and comprise a 2D network based upon planar tetranuclear lanthanide secondary building units. The 2D layers extend to a 3D framework by π–π stacking between imidazole rings and hydrogen bonding interactions. The complexes 5–8 are also isomorphous and have similar 3D frameworks fabricated through Hbidc2− and SO42− bridging dinuclear lanthanide secondary building units, and the guest water molecules are trapped in the lattice. The luminescent properties of complexes 5 and 6 exhibit characteristic europium and terbium luminescence, while 4 involves ligand-to-metal charge transfer. The magnetic properties of four complexes were also investigated.

Two novel three-dimensional (3D) coordination polymers [Cu3II(mtta)6]n (1) and [Cu2IICu3I(trz)4Br3]n·nH2O (2) (mtta = 5-methyltetrazolate, trz = 1,2,4-triazole) were synthesized and structurally characterized. Complex 1 shows a 3D porous metal–organic framework. By the topology analysis, the complicated architecture of 1 can be simplified to be the 4-connected diamond-type net. Compound 2 is a two-fold interpenetrating 3,5-connected 3D framework with new topology.Two novel three-dimensional (3D) coordination polymers [Cu3II(mtta)6]n (1) and [Cu2IICu3I(trz)4Br3]n·nH2O (2) (mtta = 5-methyltetrazolate, trz = 1,2,4-triazole) were synthesized and structurally characterized. Complex 1 shows a 3D porous metal–organic framework. By the topology analysis, the complicated architecture of 1 can be simplified to be the 4-connected diamond-type net. Compound 2 is a two-fold interpenetrating 3,5-connected 3D supramolecular framework with new topology.

Seven new organic–inorganic hybrid compounds containing inorganic polyoxometalates and trigonal organic ligand 2,4,6-tris-(3/4-pyridyl)-1,3,5-triazine (3/4-tpt), namely [Mo8O26M(Htpt)2(H2O)2]n (M = Zn (1), Co (2), Ni (3)), [Mo8O26Cu(Htpt)2(H2O)2]n·2nH2O (4), [Mo8O26(H2tpt)2]·6H2O (5), [Mn(Mo4O13)(4-tpt)2]n (6) and [Fe3(Mo4O15)(3-tpt)]n·nH2O (7), were synthesized hydrothermally and characterized by EA, IR, TG, and PXRD techniques. Single crystal X-ray structural analysis revealed that compounds 1–4 are 1-D coordination polymers constructed from [Mo8O26]4− cluster and [M(Htpt)2(H2O)2]4+ fragments. Compound 5 is an isolated cluster composed of [Mo8O26]4− anion and monodentate H2tpt2+ cation. 3-Tpt ligands in 1–5 are partially protonated and act as monodentate ligands. Octamolybdates adopt β- and γ-[Mo8O26]4− structural mode in compounds 1–4 and 5, respectively. In compound 6, each [Mo4O13]2− tetramer links four Mn(II) ions to form a 2-D wave-like polymeric layer. The 2-D [MnMo4O13] bimetallic layers are pillared by neutral 4-tpt bidentately to generate a 3-D metal–organic framework. Compound 7 is a 3-D coordination polymer constructed from 2-D [Fe3(Mo4O15)] bimetallic polymeric layer and pillared by neutral tridentate 3-tpt. These compounds are thermal stable under 250 °C. The compounds 1 and 5 display luminescence with emission maximum at 481 and 442 nm, respectively.Seven hybrid compounds [Mo8O26M(Htpt)2(H2O)2]n (M = Zn, Co, Ni, Cu), [Mo8O26(H2tpt)2]·6H2O, [Mn(Mo4O13)(4-tpt)2]n and [Fe3(Mo4O15)(3-tpt)]n·nH2O were prepared. These compounds contain β-[Mo8O26], γ-[Mo8O26], [MnMo4O13], and [Fe3(Mo4O15)] polyoxometalates, which are pillared by tpt to form varied 1-D and 3-D metal–organic frameworks.

Hydrothermal reactions of Cu(II) salts with 2,4,6-tris(3/4-pyridyl)-1,3,5-triazine (3/4-tpt) and 1,2,4,5-benzenetetracarboxylic acid (H4btec) afforded five novel coordination polymers, namely [Cu4(3-tpt)2(btec)2(H2O)4]n·6nH2O (1), [Cu(3-tpt)2(H2btec)]n (2), [Cu3(3-Htpt)2(H2btec)2(btec)]n·4nH2O (3), [Cu2(4-tpt)3(H2btec)2]n·4nH2O (4), and [Cu3(4-tpt)2(Hbtec)2(H2O)]n·3nH2O (5). These complexes exhibit various polymeric networks due to diverse coordination modes of tpt and H4btec. Complex 1 displays a 3-D metal–organic framework in which 3-tpt is an exo-tridentate ligand and μ4-btec4− coordinates to two square-pyramidal Cu(II) and two square Cu(II) ions. Complex 2 is a 1-D chain coordination polymer which contains μ2-H2btec2− bridge and monodentate 3-tpt. Complex 3 shows a 3-D metal–organic framework constructed from protonated bidentate 3-Htpt+, tridentate H2btec2− and tetradentate btec4−. Complex 4 is a 1-D ladder-like coordination polymer assembled by μ2-H2btec2−, mono- and bidentate 4-tpt. Complex 5 exhibits a porous 3-D metal–organic framework constructing from tridentate 4-tpt and μ3-Hbtec3−. Their thermal stabilities were also investigated.Five coordination polymers [Cu4(3-tpt)2(btec)2(H2O)4]n·6nH2O, [Cu(3-tpt)2(H2btec)]n, [Cu3(3-Htpt)2(H2btec)2(btec)]n·4nH2O, [Cu2(4-tpt)3(H2btec)2]n·4nH2O and [Cu3(4-tpt)2 (Hbtec)2(H2O)]n·3nH2O were prepared. These complexes exhibit various frameworks due to diverse coordination modes of tpt and H4btec. Their thermal stabilities were investigated.

Solvothermal reactions of CuSCN with 4-amine-3,5-bis(3-pyridyl)-1,2,4-triazole (3-Abpt), 5-(4-pyridyl)tetrazole (4-Ptz), and 2-(n-pyridyl)benzimidazole (n-PyHBIm, n = 4, 3, 2) in acetonitrile afford six novel coordination polymers: [Cu5(SCN)5(3-Abpt)2]n (1), [Cu(SCN)(3-Abpt)]n (2), [Cu(SCN)(4-Ptz)]n (3), [Cu2(SCN)2(4-PyHBIm)]n (4), [Cu2(SCN)2(3-PyHBIm)]n (5), and [Cu2(SCN)2(2-PyBIm)(2-PyHBIm)]n (6). All these complexes were structurally characterized by X-ray diffraction analysis. 1 is the first example of a 1,1,1,3-μ4-tetradentate thiocyanate complex which displays a three-dimensional (3D) polymeric framework constructed from thiocyanate and tetradentate 3-Abpt. 2 exhibits a two-dimensional (2D) 4.82 network constructed from unidentate thiocyanate and tridentate 3-Abpt. 3 is a one-dimensional (1D) ladder-like double-chain polymer assembled by bidentate thiocyanate and 4-Ptz ligands. 4 shows a 2D 1,1,3-μ3-thiocyanate copper 4.82 network where bidentate 4-PyHBIm locates at both sides of the 2D layer. 5 displays a 2D 63 network constructing from 1,1,3-μ3-thiocyanate and bidentate 3-PyHBIm. 6 is a 1D 21 helical chain polymer constructing from 1,3-μ2-thiocyanate and 2-PyBIm anion. Bond valence sum (BVS) analysis and magnetic susceptibility indicate that 6 is a mixed-valence compound. The coordinate diversity of thiocyanate is discussed. 1−6 are all thermally stable up to 230−290 °C. They exhibit yellow or blue luminescence originating from ligand-to-metal charge transfer or ligand-centered emission.

The reactions of metal salts with pyrazine-2,3-dicarboxylic acid (H2pzdc), pyridine-2,5-dicarboxylic acid (H2pydc), pyrazine-2,3,5,6-tetracarboxylic acid (H4pztc), 4,4′-bipyridine (bipy) and 1,10-phenanthroline (phen) afforded four new ternary complexes, namely [Co2(pzdc)2(bipy)(H2O)2]n·3nH2O (1), [Zn2(pzdc)2(bipy)(H2O)2]n·3nH2O (2), [Co(pydc)2(H2O)2](H2bipy) (3) and [Cu2(pztc)(phen)2(H2O)2]·2HNO3·2H2O (4). The metal centers are all six-coordinated. Compounds 1 and 2 are 2D coordination polymers exhibiting wave-like polymeric networks. The 2D layers are stacked in an interpenetrating mode to form double-layered frameworks, which possess ∼8 Å×6 Å tunnels occupied by (H2O)6 clusters. Compound 3 is a mononuclear supramolecular compound in which 4,4′-bipyridine is protonated and acted as a cationic building block. Compound 4 is a centro-symmetric binuclear complex. Pztc4− as a hexadentate ligand coordinates to two Cu(II) ions to form four chelating rings. Phen are arranged in an ABAB parallel fashion to form a supramolecular architecture incorporating HNO3 lattice molecule. The thermal stabilities of 1−4 and luminescence of zinc complex 2 were also investigated.

Three new copper(II) azide coordination polymers with derivatives of 1,2,4-triazole as bridging coligands, namely [Cu2(admtrz)2(N3)4]n (1) (admtrz = 4-amino-3,5-dimethyl-1,2,4-triazole), [Cu(4-abpt)(N3)2]n·2nH2O (2) (4-abpt = 4-amino-3,5-bis(4-pyridyl)-1,2,4-triazole) and [Cu3(2-ptrz)2(N3)6]n (3) (2-ptrz = 4-(2-pyridyl)-1,2,4-triazole), were prepared and characterized by elemental analyses, IR spectra and X-ray structural analyses. Compound 1 has a 1D chain structure in which Cu(II) ions are bridged by end-on (EO) azides and admtrz ligands. This compound contains three kinds of coordination modes for Cu(II) ions, including tetrahedral, square pyramidal and octahedral geometries. Compound 2 displays an interesting 3D framework structure, in which the azide ligands link Cu(II) ions in end-to-end (EE) mode affording a 2D square layer. This 2D layers are further bridged by bent 4-abpt ligands to form an interesting 3D framework. Furthermore, this structure also exhibits an alpha-Po net topology. Compound 3 displays a 1D rectangle-like chain structure linked by azides adopting end-on (EO) and end-to-end (EE) modes and 2-ptrz ligands. The IR and thermal stabilities of these coordination polymers 1–3 have also been studied.

Five new metal-organic frameworks based on 2,4,6-tris(4-pyridyl)-1,3,5-triazine (tpt) ligand have been hydrothermally synthesized. Reaction of tpt and AgNO3 in an acidic solution at 180 °C yields {[Ag(Htpt)(NO3)]NO3·4H2O}n (1). Ag(I) is trigonally coordinated by two pyridyl nitrogen and one nitrato oxygen to form a 1D zigzag chain. Reaction of tpt with CuSO4 affords {[Cu2(tpt)2(SO4)2(H2O)2]·4H2O}n (2). Copper(II) is bonded to two pyridyl nitrogen, two sulfato oxygen, and two water oxygen atoms to form an elongated octahedral geometry. Each H2O ligand bridges two copper(II), whereas sulfate bridges copper(II) via µ-1,3 and µ-1,1 fashions. The copper(II)−sulfate−H2O 2D layers are linked by bidentate tpt to form a 3D polymeric structure. Reaction of Cu(SO4)2, tpt, and 1,2,4,5-benzenetetracarboxylic acid (H4btec) in the presence of piperidine gives [Cu(tpt)(H2btec)1/2]n (3). Copper(I) is located in a trigonal-pyramidal coordination environment and coordinated by three pyridyl nitrogen of tpt in a plane, whereas a carboxylate oxygen is coordinated to the copper(I) axially. The tpt−Cu forms a layer, and the layers are linked through H2btec2− to form a 2D double-layered coordination polymer. Replacing CuSO4 with ZnI2 in the synthesis gives {[Zn(tpt)(btec)1/2]·H2O}n (4). Zinc(II) is in a distorted tetrahedral geometry and linked through bidentate tpt and exotetradentate btec4− to form a 2D coordination grid. Reaction of tpt with CuCN leads to the assembly of a 3D metal-organic framework [Cu3(CN)3(tpt)]n (5). Copper(I) is trigonally coordinated by one pyridyl nitrogen and two cyanides to form an intriguing honeycomb architecture. Luminescence study shows that 1, 3, 4, and 5 have blue fluorescence, which can be assigned to be ligand-centered emissions. Thermal analysis shows that all of these complexes are quite stable, and especially for 4, the framework is stable up to 430 °C.

Reactions of 4-amino-3,5-bis(3-pyridyl)-1,2,4-triazole (3-abpt) with metal acetates gave rise to four new complexes [Cu(3-abpt)(ip)]n·2nH2O (1), [Co(3-abpt)(ip)(H2O)2]n·2nH2O (2), [Ni(3-abpt)(tp)(H2O)2]n(3) and [Cu(3-abpt)2(CH3COO)2(H2O)2] (4) (ip = isophthalate, tp = terephthalate), which were characterized by EA, IR and X-ray crystallography. Compound 1 consists of two kinds of ring-like chain which are interconnected to form an unusual two-dimensional layered motif. Compounds 2 and 3 are both 1D ring-like infinite chains. Compound 4 is a mononuclear complex. The thermal stabilities of coordination polymers 1–3 have been investigated.

Hydrothermal reaction of CuCN with 2,5-bis(3-pyridyl)-1,3,4-oxadiazole (3-bpo) affords a wave-like infinite chain coordination polymer [Cu2(CN)2(3-bpo)]n (1). Replacement of 3-bpo by its isomer 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (4-bpo) could yields polymer [Cu(CN)(4-bpo)]n (2). In the complex 1, the bent 3-bpo ligand adopts bidentate chelating mode binds with the Cu(I)-cyanide chain to form 16-membered macrocyclic structure. The complex 2 exhibits a layered metal–organic framework, in which exo-bidentate 4-bpo ligand connects the Cu(I)-cyanide chains to form 2-D rectangle grid. Both of these Cu(I) complexes are thermal stable under 200 °C and release 3-bpo or 4-bpo ligand in 200–360 °C. Luminescent study reveals that 1 has green-light emission, while 2 has blue-light emission.

Hydrothermal reaction of CuCN, K3[Fe(CN)6] with 4-(6-amino-2-pyridyl)-1,2,4-triazole (apt) afforded a coordination polymer [Cu7(CN)7(apt)2]n (1), while solvothermal reaction of CuSCN with apt in acetonitrile afforded a coordination polymer [Cu2(SCN)2(apt)]n (2). Complex 1 shows two-dimensional polymeric network with large hexagonal channels constructing by CuCN chains and tridentate apt ligands. Complex 2 shows two-dimensional polymeric framework assembled by ladder-like [Cu(SCN)]n chains and bidentate apt ligands, in which thiocyanate acts as a tridentate bridging ligand. Both polymers are thermal stable and strong fluorescent in the solid state.

Three supramolecular compounds, [Mn2(chda)(phen)4(H2O)]·(ClO4)2·phen·4H2O (1), [Cu(mal)(bipy)]n·2nH2O (2) and [Cu(ca)2(bipy)]·2H2O (3) (chda = 1,1-cyclohexanediacetate, mal = maleate, Hca = cyanuric acid, bipy = 2,2′-bipyridine), have been synthesized and characterized by elemental analyses, IR spectra, thermal analyses and X-ray structural analyses. Compound 1 is a carboxylate-bridging binuclear complex incorporating uncoordinated 1,10-phenanthroline bonded by hydrogen bonding and π–π stacking interactions. Compound 2 is a 1D zigzag chain carboxylate coordination polymer incorporating cyclic (H2O)4 tetramers of lattice water, which further connect the zigzag chains through strong hydrogen bonds to form 2D supramolecular network. Compound 3 is a mononuclear complex in which H-bonding (H2O)8 water clusters further combine the complex through hydrogen bonds to form supramolecular framework. Thermal stabilities of 1 and 3 have also been investigated.

Two new cyano-bridged bimetallic complexes, [Cu(TAAB)Fe(CN)5(NO)]·2H2O (1) and [Mn(bpy)2(H2O)Fe(CN)5(NO)]·H2O (2) (where TAAB = tetrabenzo[b,f,j,n][1,5,9,l3]tetraaza-cyclohexadecine and bpy = 2,2′-bipyridine), have been synthesized and characterized by elemental analyses, IR spectra and TG-DSC analyses. Single crystal X-ray structure analyses revealed that the complex 1 has a cyano-bridged binuclear structure in which Cu(II) center is coordinated by tetraazacyclic TAAB ligand to form an intriguing saddle-shaped structure, and Fe(II) center is in an octahedral coordination environment with nitrosyl group trans to the cyano-bridge. In complex 2, Mn(II) center is cis six-coordinated and linked to nitroprusside though a bridging cyanide group to form a binuclear structure, while the nitrosyl group is cis to the cyano-bridge. The thermal stabilities of both complexes were investigated, which shows the nitrosyl and cyanide groups of nitroprusside released by two-steps in the temperature range of 200–380 °C.