Distinct structures of coordination polymers incorporating flexible triazole-based ligand: topological diversities, crystal structures and property studies

Six new coordination polymers, namely {[Zn(btec)(0.5)(btmb)]·2H(2)O}(n) (1), {[Co(btec)(0.5)(btmb)(H(2)O)]·3H(2)O}(n) (2), {[Cu(btec)(0.5)(btmb)]·H(2)O}(n) (3), {[Cu(4)(btc)(4)(btmb)(4)]·H(2)O}(n) (4), {[Co(3)(bta)(2)(btmb)(2)]·2H(2)O}(n) (5), [Co(Hbta)(btmb)](n) (6) (H(4)btec = 1,2,4,5-benzenetetracarboxylate, H(3)btc = 1,3,5-benzenetricarboxylate, H(3)bta = 1,2,4-benzenetricarboxylate and btmb = 4,4'-bis(1,2,4-triazol-1-ylmethyl)biphenyl), have been successfully synthesized under hydrothermal conditions. All these complexes were structurally determined by single-crystal X-ray diffraction, elemental analysis, IR, TGA and XRD. Crystal structural analysis reveals that 1 is the first example of an unusual 3D framework with (8(6)) topology containing a 2D molecular fabric structure. Complex 2 exhibits a 3D NbO network with (6(4)·8(2)) topology. In 3, Cu(II) ions are coordinated by anti-conformational btmb ligands to form left- and right-handed double helices, which are further bridged by the 4-connected btec(4-) anions to give a 3D porous network. Complex 4 presents a rare 3D gra network structure with (6(3))(6(9)·8) topology. 5 and 6 were obtained through controllable pH values of solution, 5 features a scarce binodal (3,8)-connected tfz-d framework with the trinuclear Co(II) clusters acting as nodes, whereas 6 has an extended 2D 4(4) grid-like layer and the adjacent 2D layers are interconnected by strong hydrogen bonding interactions into a 3D supramolecular framework. The structural diversities indicate that distinct organic acid ligands, the nature of metal ions and the pH value play crucial roles in modulating the formation of the resulting coordination complexes and the connectivity of the ultimate topological nets. Moreover, magnetic susceptibility measurement of 5 indicates the presence of weak ferromagnetic interactions between the Co(II) ions bridged by carboxylate groups.     

Coordination polymers of macrocyclic oxamide with 1,3,5-benzenetricarboxylate: syntheses, crystal structures and magnetic properties

Solvothermal reactions of mixed ligands H(3)BTC and macrocyclic oxamide complexes (ML, M = Cu, Ni) with M(ClO(4))(2)·6H(2)O (M = Co, Zn, Ni and Cd) afford six new complexes, including [M'(4)(BTC)(2)(ML)(2)(OH)(2)(H(2)O)(2)]·2H(2)O (M' = Co, M = Ni, for (1); M' = Zn, M = Ni, for (2); M' = Zn, M = Cu, for (3)), [Ni(3)(BTC)(2)(NiL)(2)(H(2)O)(6)]·2CH(3)OH·2H(2)O (4), [Cd(4)(BTC)(2)(HBTC)(NiL)(4)(H(2)O)]·3H(2)O (5) and [Cd(HBTC)(CuL)]·H(2)O (6) (ML, H(2)L = 2, 3-dioxo-5, 6, 14, 15-dibenzo-1,4,8,12-tetraazacyclo-pentadeca-7,13-dien; H(3)BTC = 1,3,5-benzenetricarboxylic acid). Complexes 1-3 consist of a 2D layer framework formed by the linkage of M(II)(M = Ni, Cu) and M'(4) (M' = Co, Zn) cluster via the oxamide and BTC(3-) bridges and display a (3,6)-connected network with a (4(3))(2)(4(6).6(6).8(3)) topology. The structure of 4 consists of pentanuclear [Ni(II)(5)] units and arranges in a 1D cluster chain. Complex 5 exhibits a 2D layered structure characterized by 3,4,3-connected (4.6(2))(3)(4.6(3).8(2))(4(2).6(3).8)(4(2).6) topology. Complex 6 possesses a 3D network with sra topology. The magnetic properties of complexes 1 and 4 were investigated.     

Mn(II) Coordination Polymers Based on Bi-, Tri-, and Tetranuclear and Polymeric Chain Building Units: Crystal Structures and Magnetic Properties

Five new Mn(II) coordination polymers, namely [Mn(2)(tbip)(2)(bix)] (1), [Mn(3)(tbip)(3)(bix)(2)] (2), [Mn(3)(tbip)(2)(Htbip)(2)(bib)(2)]·4H(2)O (3), [Mn(4)(tbip)(4)(bbp)(2)(H(2)O)(2)] (4), and [Mn(4)(tbip)(4)(bip)]·2H(2)O (5), were prepared by hydrothermal reactions of Mn(II) acetate with H(2)tbip (5-tert-butyl isophthalic acid) in the presence of different di-imidazolyl coligands (bix =1,4-bis(imidazol-1-ylmethyl)benzene, bib =1,4-bis(imidazol) butane, bbp =1,3-bis(benzimidazol)propane, bip =1,3-bis(imidazol)propane). All complexes were characterized by elemental analysis, IR spectra, thermogravimetric analysis, single-crystal X-ray crystallography, and powder X-ray diffraction. Single crystal X-ray studies show that these coordination polymers contain homometallic clusters varying from dimeric, trimeric, and tetrameric motifs to polymeric chains depending upon the coligands used. Complex 1 has a 3D 6-connected polycatenane network with dinuclear [Mn(2)O(2)] secondary building units. Complex 2 possesses a 3D 8-connected structure with trinuclear [Mn(3)(COO)(6)] units. Complex 3 shows a 3D pcu net based on trinuclear [Mn(3)(COO)(6)] clusters as nodes. Complex 4 features a 3D 8-connected structure constructed from the distorted square-grid tetranuclear [Mn(4)(μ(2)-COO)(8)(μ(2)-H(2)O)] units. Complex 5 shows a 3D (4,5,6)-connected net containing 1D μ-O/μ-COO alternately bridged chains. Magnetic susceptibility measurements indicate that complexes 1 and 3-5 show weak antiferromagnetic interactions between the adjacent Mn(II) ions, whereas 2 is a three-spin center homometallic ferromagnetic system.     

Co(II), Mn(II) and Cu(II)-directed coordination polymers with mixed tetrazolate-dicarboxylate heterobridges exhibiting spin-canted, spin-frustrated antiferromagnetism and a slight spin-flop transition

Three new paramagnetic ion-directed coordination frameworks, {[Co(4)(H(2)O)(2)(μ(3)-OH)(2)(atz)(2)(nip)(2)]·3H(2)O}(n) (1), {[Mn(4)(H(2)O)(2)(μ(3)-OH)(2)(atz)(2)(nip)(2)]·H(2)O·MeOH}(n) (2) and {[Cu(2)(H(2)O)(μ(3)-OH)(atz)(nip)]·2H(2)O}(n) (3), were, respectively, obtained by solvo-/hydrothermal reactions of 5-amino-1H-tetrazole (Hatz), 5-nitroisophathalic acid (H(2)nip) with an inorganic Co(II), Mn(II) or Cu(II) salt. The former two complexes are two-dimensional (2D) covalent layers built from butterfly-shaped tetranuclear M(4)(μ(3)-OH)(2) clusters and double atz(-) and nip(2-) linkers. Whereas complex 3 is a 3D framework with scarcely observed corner-sharing Cu(3)(μ(3)-OH) Δ-chains extended by nip(2-) linkages, in which the anionic atz(-) ligand acts as a reinforcement to consolidate the Δ-chain. Magnetically, due to the interplay of the anisotropy of spin carrier and magnetic exchange interactions from the adjacent spin carriers, the complexes exhibit spin-canted antiferromagnetism with a Néel temperature lower than 2.0 K for 1 and an antiferromagnetic ordering with a slight field-induced spin-flop transition for 2. In contrast, complex 3 with a local Kagomé sublattice displays spin-frustrated antiferromagnetic behavior with magnetic ordering at 16.0 K.     

Syntheses,Crystal Structures and DNA-Binding Properties of Zn(Ⅱ)and Mn(Ⅱ)Complexes Based on Imidazole Derivatives and Carboxylic Acid

Complexes[Zn(pbm)(5-hip)3](1),[Zn(pbm)(5-nip)3](2),[Mn(pbm)(H3btc)2(H2O)](3)and[Mn(pbm)(5-nip)3](4),where H2HIPA=5-hydroxyisophthalic acid,H2nip=5-nitroisophtha...     

Assembly and properties of transition-metal coordination polymers based on semi-rigid bis-pyridyl-bis-amide ligand: effect of polycarboxylates on the dimensionality

Seven new coordination polymers, [Co()(1,3-BDC)(H(2)O)(3)]·H(2)O (), [Co()(1,2-BDC)(H(2)O)]·H(2)O (), [Co(3)()(1,2,4-BTC)(2)(H(2)O)(4)]·4H(2)O (), [Co()(NPH)]·2H(2)O (), [Cu()(1,3-BDC)] (), [Cu()(1,2-BDC)] (), [Cu()(1,3,5-HBTC)(H(2)O)](2)·2H(2)O () ( = N,N'-bis(pyridin-3-yl)cyclohexane-1,4-dicarboxamide, 1,3-H(2)BDC = 1,3-benzenedicarboxylic acid, 1,2-H(2)BDC = 1,2-benzenedicarboxylic acid, 1,2,4-H(3)BTC = 1,2,4-benzenetricarboxylic acid, H(2)NPH = 3-nitrophthalic acid and 1,3,5-H(3)BTC = 1,3,5-benzenetricarboxylic acid) have been hydrothermally synthesized by assembling transition-metal cobalt-copper salts with semi-rigid bis-pyridyl-bis-amide ligand and different aromatic polycarboxylic acids. Complex exhibits a one-dimensional (1D) sinusoidal-like chain, which is further assembled into a three-dimensional (3D) supramolecular framework through hydrogen-bonding interactions. Complex possesses a 3D framework with 4-connected 6(6) topology, which contains a two-dimensional (2D) distorted asymmetric hexagonal grid. When 1,2,4-BTC is used in complex , a 3D framework with (6(3)·8(2)·10)(2)(6(5)·8)(2)(8) topology is constructed. Complex possesses a 3D framework with 4-connected 6(6) topology, which is similar to that of except for containing a 2D symmetric hexagonal grid. When Co(II) ion is replaced by Cu(II) ion, the 3D framework of complex with (4·6(2))(4·6(6)·8(3)) topology based on and 1,3-BDC ligands is obtained. Complex shows a 2D cross network consisting of a superposed Cu- 1D chain and 1,2-BDC, which is further expanded into a 3D supramolecular framework by hydrogen-bonding interactions. In complex , 1,3,5-HBTC is employed as the auxiliary ligand, and a 3D supramolecular framework based on the undulated 2D layers is formed through π-π stacking and hydrogen-bonding interactions. Both the metal ions and polycarboxylates play important roles in the construction of the title complexes. In addition, the electrochemical behaviors and the fluorescence properties of the seven complexes have been investigated.     

Syntheses,Structures and Photocatalytic Degradation Properties of Two Copper(Ⅱ)Coordination Polymers with Flexible Bis(imidazole)Ligand

Two copper(Ⅱ)coordination polymers{[Cu(bib)(nip)]·1.5H2O}n(1)and[Cu2(bib)(glu)2]n(2)(bib= 1,4-bis(2-methyl-imidazol-1-yl)butane,H2nip = 5-nitroisophthalic acid,...     

Inorganic-organic hybrid compounds based on octamolybdates and metal-organic fragments with flexible multidentate ligand: syntheses, structures and characterization

Six polyoxometalate-based (POM) hybrid materials based on octamolybdate building blocks and metal-organic fragments with flexible multidentate ligand, namely [Cu(II)(2)(ttb)(2)(β-Mo(8)O(26))(H(2)O)(2)]·2H(2)O (1), Cu(I)(4)(ttb)(2)(β-Mo(8)O(26))(H(2)O) (2), [Cu(I)(4)(ttb)(3)(β-Mo(8)O(26))] (3), [Ni(2)(ttb)(2)(β-Mo(8)O(26))(H(2)O)(6)]·2H(2)O (4), [Zn(2)(ttb)(2)(α-Mo(8)O(26))(H(2)O)(2)] (5), and [Ag(4)(ttb)(2)(β-Mo(8)O(26))] (6), where ttb = 1,3,5-tris(1,2,4-triazol-1-ylmethyl)-2,4,6-trimethyl benzene, have been synthesized under hydrothermal conditions. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, TGA, IR spectra, and electrochemistry. Compounds 1 and 2 exhibit three-dimensional (3D) 2-fold interpenetrating frameworks with (3,6)-connected (4(1)·6(2))(4(2)·6(10)·10(3)) and (3,4)-connected (6(2)·8(1))(2)(6(2)·8(4)) topologies, respectively. We are not aware of any other examples of interpenetrating (3,6)- and (3,4)-connected frameworks which involves the octamolybdates. Compound 3 shows a rare two-dimensional (2D) 2-fold interpenetrating network structure. In compound 4, a 3D supramolecular framework with the channels is constructed by the hydrogen-bonding interactions between (β-Mo(8)O(26))(4-) polyanions and the Ni-ttb double layers, in which the guest (β-Mo(8)O(26))(4-) anions are included. If ZnO interactions are considered, the structure of 5 is a 3D (3,4)-connected framework with (4·8(2))(4·8(2)·10(3)) topology. In 6, the ttb ligand as a tetradentate ligand links the Ag atoms to yield a 2D POM-based network. By careful inspection of the structures of 1-6, it can be seen that the ttb ligand, the metal ion and the coordination mode of the octamolybdate anion play important roles in the formation of the POM-based MOFs.     

Six new metal-organic frameworks based on polycarboxylate acids and V-shaped imidazole-based synthon: syntheses, crystal structures, and properties

Solvothermal reactions of 4,4'-bis(imidazol-1-yl)diphenyl ether (BIDPE) with deprotonated 5-hydroxy-isophthalic acid (5-OH-H(2)bdc), and benzene-1,3,5-tricarboxylic acid (H(3)btc) in the presence of cadmium(II), zinc(II), cobalt(II), nickel(II), and manganese(II) salts in H(2)O or H(2)O/DMF produced six new complexes, namely, [Cd(BIDPE)(5-OH-bdc)·H(2)O](n) (1), [Co(BIDPE)(5-OH-bdc)·H(2)O](n) (2), [Zn(3)(BIDPE)(3)(5-OH-bdc)(3)·4H(2)O](n) (3), [Ni(BIDPE)(2)(5-OH-bdc)(H(2)O)·3H(2)O](n) (4), {[Mn(2)(BIDPE)(2)(5-OH-bdc)(2)](n) (5), and [Ni(BIDPE)(2)(Hbtc)(H(2)O)](n) (6). These complexes were characterized by elemental analysis, IR spectroscopy, and X-ray single-crystal diffraction. Compounds 1 and 2 reveal the same two-dimensional (2D) sheets with a 32-membered [(Cd/Co)(2)(BIDPE)(2)] metallocyclic ring constructed from BIDPE and 5-OH-H(2)bdc with Cd or Co salts. For compound 3, six identical 2D sheets are polycatenated in parallel to form a rare 2D → 2D framework; it displays ferroelectric behavior with a remnant electric polarization (P(r)) of 0.033 μC/cm(2) and an electric coercive field (E(c)) of 11.15 kV/cm. In compounds 4 and 6, only one carboxyl group coordinated to the Ni atom from 5-OH-H(2)bdc or H(3)btc. Compound 5 exists as binuclear Mn clusters, which are linked by BIDPE and 5-OH-H(2)bdc to generate a 2D sheet and displays weak antiferromagnetic character. In addition, the thermal stabilities and photochemical properties of these new complexes have been studied.     

Complexes of copper(II) with 3-(ortho-substituted phenylhydrazo)pentane-2,4-diones: syntheses, properties and catalytic activity for cyclohexane oxidation

Reactions of copper(II) with 3-phenylhydrazopentane-2,4-diones X-2-C(6)H(4)-NHN=C{C(=O)CH(3)}(2) bearing a substituent in the ortho-position [X = OH (H(2)L(1)) 1, AsO(3)H(2) (H(3)L(2)) 2, Cl (HL(3)) 3, SO(3)H (H(2)L(4)) 4, COOCH(3) (HL(5)) 5, COOH (H(2)L(6)) 6, NO(2) (HL(7)) 7 or H (HL(8)) 8] lead to a variety of complexes including the monomeric [CuL(4)(H(2)O)(2)]·H(2)O 10, [CuL(4)(H(2)O)(2)] 11 and [Cu(HL(4))(2)(H(2)O)(4)] 12, the dimeric [Cu(2)(H(2)O)(2)(μ-HL(2))(2)] 9 and the polymeric [Cu(μ-L(6))](n)] 13 ones, often bearing two fused six-membered metallacycles. Complexes 10-12 can interconvert, depending on pH and temperature, whereas the Cu(II) reactions with 4 in the presence of cyanoguanidine or imidazole (im) afford the monomeric compound [Cu(H(2)O)(4){NCNC(NH(2))(2)}(2)](HL(4))(2)·6H(2)O 14 and the heteroligand polymer [Cu(μ-L(4))(im)](n)15, respectively. The compounds were characterized by single crystal X-ray diffraction (complexes), electrochemical and thermogravimetric studies, as well as elemental analysis, IR, (1)H and (13)C NMR spectroscopies (diones) and ESI-MS. The effects of the substituents in 1-8 on the HOMO-LUMO gap and the relative stability of the model compounds [Cu(OH)(L(8))(H(2)O)]·H(2)O, [Cu(L(1))(H(2)O)(2)]·H(2)O and [Cu(L(4))(H(2)O)(2)]·H(2)O are discussed on the basis of DFT calculations that show the stabilization follows the order: two fused 6-membered > two fused 6-membered/5-membered > one 6-membered metallacycles. Complexes 9, 10, 12 and 13 act as catalyst precursors for the peroxidative oxidation (with H(2)O(2)) of cyclohexane to cyclohexanol and cyclohexanone, in MeCN/H(2)O (total yields of ca. 20% with TONs up to 566), under mild conditions.     

Synthesis, structure, and characterization of three series of 3d-4f metal-organic frameworks based on rod-shaped and (6,3)-sheet metal carboxylate substructures

Three series of porous lanthanide metal-organic coordination polymers, namely [Cu(bpy)Ln(3)(ip)(5)(Hip)(H(2)O)] [Ln = Er (1a), Y (1b), Eu (1c); bpy = 2,2'-bipyridine, H(2)ip=isophthalic acid], [Cu(3)(bpy)(2)Ln(2)(ip)(6)(H(2)O)(5)] [Ln = Yb (2a), Gd (2b), Tb (2c)], and [Cu(3)Ln(2)(ip)(6)] [Ln = Eu (3a), Gd (3b)] have been synthesized hydrothermally by the reaction of the combination of 3d-4f metal centers and N-/O-donor ligands. X-ray diffraction analyses reveal that polymers 1a-c and 2a-c, as well as 3a, b are isomorphous in structure. Polymers 1a-c consist of 3D alpha-Po networks based on a inorganic rod-shaped secondary building units (SBUs) of {Er(6)Cu(2)(bipy)(2)(O(2)C)(11)} which are 27.03 A in length. Polymers 2a-c also contain 3D alpha-Po networks, constructed from shorter (14.79 A) but similarly rod-shaped SBUs of {Yb(2)Cu(3)(bpy)(2)(O(2)C)(12)}. The structure also contains hydrogen-bonded (H(2)O)(6) chains which can be reversibly dehydrated/rehydrated. Polymers 3a, b contain metal carboxylate substructures which have 2D (6,3) topologies; these layers are bridged by the ip(2-) ligands to give an overall 3D network which contains two sorts of cavities. This series of Ln-Cu coordination polymers are further characterized by antiferromagnetic behavior.     

A series of pillar-layer metal-organic frameworks based on 5-aminoisophthalic acid and 4,4'-bipyridine

Four new compounds, [Cd(5-aip)(bpy)]·1.5DMA (1), [Cu(5-aip)(bpy)]·1.3DMA (2), [Co(5-aip)(bpy)]·1.6DMA (3), and [Cd(5-aip)(bpy)(0.5)(H(2)O)]·1.3DMA (4), based on 5-aminoisophthalic acid and 4,4'-bipyridine, have been synthesized by the solvothermal method and structurally determined using single crystal X-ray diffraction. Compounds 1-3 are structurally similar and show non-interpenetrating three-dimensional (3D) pillar-layer frameworks, while compound 4 displays a two-dimensional (2D) (3,4)-connected parallel non-interpenetrating architecture. In all these compounds, 1D rectangular channels are observed and the ligand 5-aminoisophthalic acid exhibits three kinds of coordination modes. Furthermore, 1 displays a single-crystal-to-single-crystal transformation when immersed in a methanol solution. More significantly, 1 can absorb and deliver I(2) molecules by means of its channels, and could induce a reversible luminescent transformation from quenching to the initial state. The luminescent properties of 1 and 4 have also been studied.     

Syntheses, structures and properties of two unusual silver-organic coordination networks: 1D→1D tubular intertwinement and existence of an infinite winding water chain

Two unusual metal-organic frameworks {[Ag(2)(Hbtc)(bpy)(2)]·(H(2)O)(2)}(n) (1), {[Ag(3)(btc)(bpy)(3)(H(2)O)]·(H(2)O)(7)}(n) (2) (H(3)btc = 1,2,3-benzenetricarboxylic acid, bpy = 4,4'-bipyridine) have been synthesized and characterized by single crystal X-ray diffraction. Complex 1 features an infinite 1D→1D tubular intertwinement network, while complex 2 exhibits a double ladder structure which contains rare winding water chains. Both infinite 1D→1D tubular chains in complex 1 and double ladder in 2 are mutually interconnected by hydrogen bonding and π···π stacking interactions into three-dimensional (3D) supramolecular networks. In addition, thermogravimetric analysis, powder X-ray diffraction (XRD), and photoluminescent behavior of the complexes have also been investigated.     

Syntheses,Structures, Electrochemistry,and Electrocatalysis of Three Copper(II) Coordination Polymers constructed from 5‐[4‐(1H‐Imidazol‐1‐yl)phenyl]‐1H‐tetrazole

Three coordination polymers (CPs) based on the 5‐[4‐(1H‐imidazol‐1‐yl)phenyl]‐1H‐tetrazole ( HL ) ligand, namely, [Cu(μ₂‐ L )(μ₄‐pbda)(H₂O)] ( 1 ), [Cu₂(μ‐Hbtc)(H₂btc)(μ₃‐OH)(μ₄‐ HL )] ( 2 ) and [Cu₅(μ₃‐ L )(μ₄‐ L )(μ₃‐ip)(μ₃‐OH)(H₂O)₂] · 2H₂O ( 3 ) (H₂pbda = 1,4‐benzenedicarboxylic acid, H₃btc = 1,3,5‐benzenetricarboxylic acid, H₂ip = isophthalic acid) were hydrothermally synthesized and structurally characterized. Complex 1 represents “weave”‐type 2D layers consisting of wave‐like 1D chains and 1D straight chains, which are further connected by hydrogen bonds to form a 3D supramolecular structure. Complex 2 exhibits a uninodal (4)‐connected 2D layer with a point symbol of {4⁴ · 6²}, in which the L ligand can be described as μ₅‐bridging and the H₂btc^– ions display multiple kinds of coordination modes to connect Cu^II ions into 1D “H”‐type Cu‐H₂btc chains. In complex 3 , 2D Cu‐ L layers with two kinds of grids and 1D “stair”‐type Cu‐ip chains link each other to construct a 3D {4¹² · 6³} framework, which contains the pentanuclear subunits. Deprotonated degree and coordination modes of carboxylate ligands may consequentially influence the coordination patterns of main ligands and the final structures of complexes 1 – 3 . Furthermore, electrochemical behaviors and electrocatalytic activities of the title complexes were analyzed at room temperature, suggesting practical applications in areas of electrocatalytic reduction toward nitrite and hydrogen dioxide in aqueous solutions, respectively.     

Synthesis, structures and properties of Cu(II) and Mn(II) complexes with 1,10-phenanthroline-2-carboxylic acid and 2,2'-bipyridine ligands

Four new 2,2'-bipyridine and 1,10-phenanthroline complexes, namely [Mn(phenca)(2)]·(H(2)O)(2) (1), [Cu(4)(phen)(4)(OH-)(4)(H(2)O)(2)](DMF)(4)(ClO(4)-)(4)(H(2)O) (2), [Cu(2)(2,2-bipy)(2)(C(2)O(4)2-)(H(2)O)(2)(NO(3))(2)] (3) and [Cu(2,2-bipy)(2)(ClO(4)-)](ClO(4)-) (4) (2,2'-bpy = 2,2'-bipyridine, Hphenca = 1,10-phenanthroline-2-carboxylic acid) have been synthesized by a hydrothermal reaction. The products were characterized by elemental analysis, infrared spectroscopy and X-ray crystal diffraction. While strong hydrogen bonds play central roles in the formation of the 3D structure, the combined influence of the weak interactions such as π···π interactions is also evident in the structures. A preliminary investigation on the ion exchange properties of the complexes is presented.     

Synthesis, structural characterization and anion-sensing studies of metal(II) complexes based on 3,3',4,4'-oxydiphthalate and N-donor ligands

Using a multicarboxylate ligand, 3,3',4,4'-oxydiphthalic acid (H(4)ODPA), and N-donor ligands, five metal(II)-ODPA complexes formulated as Cu(4)(ODPA)(2)(L1)(4)(H(2)O)(10)·2H(2)O (L1 = 4-(2-(pyridin-4-yl)vinyl)pyridine) (1), Co(H(2)ODPA) (L1)(H(2)O) (2), Zn(2)(ODPA)(2)(H(2)PIP)(2)·H(2)O (PIP = 1,3-bis(4-piperidinyl)propane) (3), Mn(2)(ODPA)(phen)(H(2)O)(2) (phen = phenanthroline) (4) and Cu(2)(H(2)ODPA)(2)(phen)(4)·H(2)O (5) have been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Complex 1 shows a three dimensional (3D) framework with an unprecedented (4.6(4).8)(2)(4(2).6(4)) topology generated by the polycatenation of 2D layers. Complex 2 exhibits a uninodal 4-connected 3D architecture with 6(5)8-cds topology. Complex 3 shows a uninodal 2D layer with 4(4)-sql topology. Complex 4 has a binodal (4,6)-connected non-interpenetrated 3D architecture with (3.4(3).5.6)(3(2).4(3).5(4).6(4).7(2)) topology. Complex 5 is a mononuclear Cu(II) complex. Complexes 1 and 5 can irreversibly and reversibly detect SCN(-), Cl(-), Br(-) and I(-) in water, respectively. Complexes 2-4 are not feasible candidates for colorimetric detection of anions in aqueous solution. The metal(II) species and the structure of the metal complex play important roles in the colorimetric detection.     

Highly porous 4,8-connected metal-organic frameworks: synthesis, characterization, and hydrogen uptake

A series of highly porous 4,8-connected isoreticular MOFs of the scu topology [Cu(4)(L(1))(H(2)O)(4)]·20DEF, [Cu(4)(L(2))(H(2)O)(4)]·16DMF·5H(2)O, and [Cu(4)(L(3))(H(2)O)(4)]·14DMF (L(1)-L(3) are (R)-1,1'-binaphthyl-derived octacarboxylate bridging ligands) were synthesized and characterized by single-crystal X-ray crystallography. Although the frameworks exhibit some distortion during the solvent removal process, the high-connectivity nature of the building blocks helps in stabilizing the frameworks, leading to high surface areas (S(BET) = 1189-2448 m(2)/g) and significant hydrogen uptake of up to 1.8 wt % (77 K, 1 atm).     

Syntheses, structures, and magnetic properties of a family of tetra-, hexa-, and nonanuclear Mn/Ni heterometallic clusters

A family of Mn(III)/Ni(II) heterometallic clusters, [Mn(III)(4)Ni(II)(5)(OH)(4)(hmcH)(4)(pao)(8)Cl(2)]·5DMF (1·5DMF), [Mn(III)(3)Ni(II)(6)(N(3))(2)(pao)(10)(hmcH)(2)(OH)(4)]Br·2MeOH·9H(2)O (2·2MeOH·9H(2)O), [Mn(III)Ni(II)(5)(N(3))(4)(pao)(6)(paoH)(2)(OH)(2)](ClO(4))·MeOH·3H(2)O (3·MeOH·3H(2)O), and [Mn(III)(2)Ni(II)(2)(hmcH)(2)(pao)(4)(OMe)(2)(MeOH)(2)]·2H(2)O·6MeOH (4·2H(2)O·6MeOH) [paoH = pyridine-2-aldoxime, hmcH(3) = 2, 6-Bis(hydroxymethyl)-p-cresol], has been prepared by reactions of Mn(II) salts with [Ni(paoH)(2)Cl(2)], hmcH(3), and NEt(3) in the presence or absence of NaN(3) and characterized. Complex 1 has a Mn(III)(4)Ni(II)(5) topology which can be described as two corner-sharing [Mn(2)Ni(2)O(2)] butterfly units bridged to an outer Mn atom and a Ni atom through alkoxide groups. Complex 2 has a Mn(III)(3)Ni(II)(6) topology that is similar to that of 1 but with two corner-sharing [Mn(2)Ni(2)O(2)] units of 1 replaced with [Mn(3)NiO(2)] and [MnNi(3)O(2)] units as well as the outer Mn atom of 1 substituted by a Ni atom. 1 and 2 represent the largest 3d heterometal/oxime clusters and the biggest Mn(III)Ni(II) clusters discovered to date. Complex 3 possesses a [MnNi(5)(μ-N(3))(2)(μ-OH)(2)](9+) core, whose topology is observed for the first time in a discrete molecule. Careful examination of the structures of 1-3 indicates that the Mn/Ni ratios of the complexes are likely associated with the presence of the different coligands hmcH(2-) and/or N(3)(-). Complex 4 has a Mn(III)(2)Ni(II)(2) defective double-cubane topology. Variable-temperature, solid-state dc and ac magnetization studies were carried out on complexes 1-4. Fitting of the obtained M/(Nμ(B)) vs H/T data gave S = 5, g = 1.94, and D = -0.38 cm(-1) for 1 and S = 3, g = 2.05, and D = -0.86 cm(-1) for 3. The ground state for 2 was determined from ac data, which indicated an S = 5 ground state. For 4, the pairwise exchange interactions were determined by fitting the susceptibility data vs T based on a 3-J model. Complex 1 exhibits out-of-phase ac susceptibility signals, indicating it may be a SMM.     

New coordination polymers with extended arm cyclotriguaiacyclene ligands: 1D chains, and interpenetrating or polycatenating 2D (4(2).6(2))(4.6(2))2 networks

A series of new 1D chain and 2D coordination polymers with cyclotriguaiacylene-type ligands are reported. A zig-zag 1D coordination chain is found in complex [Cd(2)(4ph4py)(NO(3))(3)(H(2)O)(2)(DMA)(2)]·(NO(3))·(DMA)(4), where 4ph4py = tris[4-(4-pyridyl)benzoyl]-cyclotriguaiacylene and DMA = dimethylacetamide, while complex [Zn(4ph4py)(2)(CF(3)COO)(H(2)O)]·(CF(3)COO)(NMP)(7), where NMP = N-methylpyrrolidone, has a doubly bridged coordination chain structure. Complexes [M(3ph3py)(NO(3))(2)]·(NMP)(4) where M = Co or Zn, 3ph3py = tris[3-(3-pyridyl)benzoyl]cyclotriguaiacylene, are isostructural and feature 1D ladder coordination chains. Complexes [Cd(2)(4ph4py)(2)(NO(3))(4)(NMP)]·(NMP)(9)(H(2)O)(4) and [Co(4ph4py)(H(2)O)(2)]·(NO(3))(2)·(DMF)(2), where DMF = dimethylformamide, both have (3,4)-connected 2D coordination polymers with a rare (4(2).6(2))(4.6(2))(2) topology. A 2D coordination polymer with this topology is also found in complex [Co(2)(3ph4py)(2)(NO(3))(H(2)O)(5)]·(NO(3))(3)·(DMF)(9) where 3ph4py = tris[3-(4-pyridyl)benzoyl]cyclotriguaiacylene. All 2D coordination polymer complexes are interpenetrating or polycatenating. [Co(2)(3ph4py)(2)(NO(3))(H(2)O)(5)](3+)polymers form a 2D→3D polycatenation showing self-complementary "hand-shake" interactions between the host-type ligands.     

1,2,4-Triazole functionalized adamantanes: a new library of polydentate tectons for designing structures of coordination polymers

A series of functionalized adamantanes: 1,3-bis(1,2,4-triazol-4-yl)(tr(2)ad); 1,3,5-tris(1,2,4-triazol-4-yl)-(tr(3)ad); 1,3,5,7-tetrakis(1,2,4-triazol-4-yl)adamantanes (tr(4)ad) and 3,5,7-tris(1,2,4-triazol-4-yl)-1-azaadamantane (tr(3)ada) were developed as a new family of geometrically rigid polydentate tectons for supramolecular synthesis of framework solids. The coordination compounds were prepared under hydrothermal conditions; their structures reveal a special potential of the triazolyl adamantanes for the generation of highly-connected and open frameworks as well as structures based upon polynuclear metal clusters assembled with short-distance N(1),N(2)-triazole bridges. Complexes [Cd{L}(2)]A·nH(2)O [L = tr(3)ad, A = 2NO(3)(-) (4), CdCl(4)(2-) (5); L = tr(3)ada, A = CdI(4)(2-) (7)] are isomorphous and adopt a layered 3,6-connected structure of CdI(2) type. [{Cu(3)(OH)}(2)(SO(4))(5)(H(2)O)(2){tr(3)ad}(3)]·26H(2)O (6) is a layered polymer based upon Cu(3)(μ(3)-OH) nodes and trigonal tr(3)ad links. In [Cu(3)(OH)(2){tr(3)ada}(2)(H(2)O)(4)](ClO(4))(4) (8), [Cu(2){tr(3)ada}(2)(H(2)O)(3)](SO(4))(2)·7H(2)O (9) and [Cd(2){tr(3)ada}(3)]Cl(4)·28H(2)O (10) (UCl(3)-type net) the organic tripodal ligands bridge polynuclear metal clusters. Complexes [Ag{tr(4)ad}]NO(3)·3.5H(2)O (11) and [Cu{tr(4)ad}(H(2)O)](ClO(4))(2)·3H(2)O (12) have 3D SrAl(2)-type frameworks with the metal ions and adamantane tectons as topologically equivalent tetrahedral nodes, while in [Cd(3)Cl(6){tr(4)ad}(2)]·9H(2)O (13) the ligands bridge trinuclear six-connected Cd(3)Cl(6)(μ-tr)(4)(tr)(2) clusters. In the compounds [Cd(2){tr(2)ad}(4)(H(2)O)(4)](CdBr(4))(2)·2H(2)O (2) and [Cd{tr(2)ad}(4){CdI(3)}(2)]·4H(2)O (3) the bitopic ligands provide simple links between the metal ions, while in [Ag(2){tr(2)ad}(2)](NO(3))(2)·2H(2)O (1) the ligand is tetradentate and generates a 3D framework.