Copper(II) complexes with monocarboxylate ligands bearing different substituent groups: Synthesis and spectroscopic studies

In our continuing efforts to explore the effects of substituent groups of ligands in the formation of supramolecular coordination structures, seven new Cu^II complexes formulated as [Cu₂(L¹)₄(DMF)₂] (1), {[Cu₂(L¹)₄(Hmta)](H₂O)_0.75}_∞ (2), [Cu₂(L²)₄(2,2′-bipy)₂] (3), [Cu₂(L³)₄(H₂O)₂] (4), [Cu₂(L³)₄(Hmta)]_∞ (5), [Cu₂(L³)₄(Dabco)]_∞ (6) and [Cu₂(L³)₄(Pz)]_∞ (7) with three monocarboxylate ligands bearing different substituent groups HL¹-HL³ (HL¹ = phenanthrene-9-carboxylic acid, HL² = 2-phenylquinoline-4-carboxylic acid, HL³ = adamantane-1-carboxylic acid, Hmta = hexamethylenetetramine, 2,2′-bipy = 2,2′-bipyridine, Dabco = 1,4-diazabicyclo[2.2.2] octane and Pz = pyrazine), have been prepared and characterized by X-ray diffraction. In 1, 2 and 4-7, each Cu^II ion is octahedrally coordinated, and carboxylate acid acts as a syn-syn bridging bidentate ligand. While each Cu^II ion in 3 is penta-coordinated in a distorted square-pyramidal geometry. 1 and 4 both show a dinuclear paddle-wheel block, while 2, 5, 6 and 7 all exhibit an alternated 1D chain structure between dinuclear paddle-wheel units of the tetracarboxylate type Cu₂-(RCO₂)₄ and the bridging auxiliary ligands Hmta, Dabco and Pz. Furthermore, 3 has a carboxylic unidentate and μ_1,1-oxo bridging dinuclear structure with the chelating auxiliary ligand 2,2′-bipy. Moreover, complexes 1-6 were characterized by electron paramagnetic resonance (EPR) spectroscopy.     

Three new multidimensional organic-inorganic hybrids based on polyoxometalates and copper coordination polymers with 4,4′-bipyridine ligands

Three new organic-inorganic hybrid materials with 4,4′-bipy ligands and copper cations as linkers, [Cu^II(H₂O)(4,4′-bipy)₂][Cu^II(H₂O)(4,4′-bpy)₂]₂H[Cu^IIP₈Mo₁₂O₆₂H₁₂] · 5H₂O (1), [Cu^I(4,4′-bipy)][Cu^II(4,4′-bipy)]₂ (BW₁₂O₄₀) · (4,4′-bipy) · 2H₂O (2) and [Cu^I (4,4′-bipy)]₃ (PMo₁₂O₄₀) · (pip) · 2H₂O (3) (pip = piperazine; 4,4′-bipy = 4,4′-bipyridine), have been hydrothermally synthesized. The single X-ray structural analysis reveals that the structure of 1 is constructed from [Cu(H₂O)(4,4′-bipy)₂] complexes into a novel, three-dimensional supermolecular network with 1-D channels in which Cu[P₄Mo₆]₂ dimer clusters reside. To the best of our knowledge, compound 1 is the first complex in which the [P₄Mo₆] clusters have been used as a non-coordinating anionic template for the construction of a novel, three-dimensional supermolecular network. Compound 2 is constructed from the six-supported [BW₁₂O₄₀]⁵⁻ polyoxoanions and [Cu^I(4,4′-bipy)] and [Cu^II(4,4′-bipy)] groups into a novel, 3-D network. Compound 3 exhibits unusual 3-D supramolecular frameworks, which are constructed from tetrasupporting [PMo₁₂O₄₀]³⁻ clusters and [Cu^I (4,4′-bipy)_n] coordination polymer chains. The electrochemical properties of 2 and 3 have been investigated in detail.     

Oxime-functionalized diazamesocyclic derivates and their metal complexes: Effect of the ligand backbones and anions on the generation of novel monomeric and mono-μ-Cl dimeric Cu complexes

Two oxime-functionalized diazamesocyclic derivates, namely, N,N′-bis(acetophenoneoxime)-1,4-diazacycloheptane (H₂L¹) and N,N′-bis(acetophenonoxime)-1,5-diazacyclooctane (H₂L²), have been prepared and characterized. Both ligands (obtained in the hydrochloride form) can form stable metal complexes with Cu^II and Ni^II salts, the crystal structures of which were determined by X-ray diffraction technique. The reactions of H₂L¹ with Cu(ClO₄)₂ and Ni(ClO₄)₂ afford a penta-coordinated mononuclear complex [Cu(H₂L¹)Cl] · ClO₄ (1) and a four-coordinated monomeric [Ni(HL¹)] · ClO₄ (2), in which the ligand is monodeprotonated. The ligand H₂L² also forms a quite similar mononuclear [Ni(HL²)] · ClO₄ complex with Ni(ClO₄)₂, according to our previous work. However, reactions of different Cu^II salts [Cu(ClO₄)₂, CuCl₂ and Cu(NO₃)₂ for 3, and CuSO₄ for 4] with H₂L² in the presence of NaClO₄ yield two unusual mono-μ-Cl dinuclear Cu^II complexes [Cu₂(HL²)₂Cl] · (ClO₄) (3), and [Cu₂(H₂L²)(HL²)Cl] · (ClO₄)₂ · (H₂O)(4). These results indicate that the resultant Cu^II complexes (1, 3 and 4) are sensitive to the backbones of diazamesocycles and even auxiliary anions.     

Metal-regulated assemblies of Cu, Ni, and Zn complexes with isoquinoline-3-carboxylate displaying diverse supramolecular networks

Three distinct coordination complexes, viz. {[Cu(μ-L)₂] · (H₂O)₄}_n (1), [Ni(L)₂(CH₃OH)₂] (2), and [Zn(L)₂(H₂O)₂] · (H₂O)₂ (3), have been prepared by the reactions of metal nitrates with isoquinoline-3-carboxylic acid (HL). X-ray single-crystal diffraction suggests that 1 is a 1D chain coordination polymer in which the Cu^II ions are connected by carboxylates, whereas complexes 2 and 3 represent discrete mononuclear species. In all the cases, the coordination entities are further organized via hydrogen-bonding interactions to generate multifarious supramolecular networks. Remarkably, a well-resolved 1D water morphology is observed for the first time in the crystalline lattice of 1 along [1 0 0], which consists of edge-sharing tetrameric subunits and stabilized by the metal-organic host surroundings.     

Three isomorphous threefold interpenetrated 2D supramolecular frameworks: Synthesis, structure and sorption properties

Strategically designed and synthesized three isomorphous mononuclear complex, M(bpee)₂(6-me-2,3-pyrdcH)₂ [M = Co^II (1), Ni^II (2) and Fe^II (3)] using the mixed ligand system. Structure determination reveals that each mononuclear fragment is engaged in bidirectional H-bonding (O-H···N) interactions forming a 2D supramolecular rectangular grid. Each rectangular grid undergoes threefold interpenetration resulting a 2D interpenetrated supramolecular framework with hydrophobic small pores. CO₂ sorption at 195 K in 1 shows no occlusion in the pore surface, however hysteretic sorption observed with H₂O and MeOH, correlated with the H-bonding interaction of H₂O and MeOH with the pendant carboxylate O-atoms, which are aligned on the 2D surface.     

Syntheses, crystal structures and magnetic properties of trinuclear and [3 × 1 + 1 × 2] pentanuclear complexes derived from a compartmental ligand: Role of solvent on nuclearity and number of components

Reaction of [Cu^IIL⊂(H₂O)] (H₂L = N,N′-ethylenebis(3-ethoxysalicylaldimine)) with nickel(II) perchlorate in 1:1 ratio in acetone produces the trinuclear compound [(Cu^IIL)₂Ni^II(H₂O)₂](ClO₄)₂ (1). On the other hand, on changing the solvent from acetone to methanol, reaction of the same reactants in same ratio produces the pentametallic compound [(Cu^IIL)₂Ni^II(H₂O)₂](ClO₄)₂·2[Cu^IIL⊂(H₂O)]·2MeOH (2A), which loses solvated methanol molecules immediately after its isolation to form [(Cu^IIL)₂Ni^II(H₂O)₂](ClO₄)₂·2[Cu^IIL⊂(H₂O)] (2B). Clearly, formation of 1 versus 2A and 2B is solvent dependent. Crystal structures of 1 and 2A have been determined. Interestingly, compound 2A is a [3 × 1 + 1 × 2] cocrystal. The cryomagnetic profiles of 1 and 2B indicate that the two pairs of copper(II)···nickel(II) ions in the trinuclear cores in both the complexes are coupled by almost identical moderate antiferromagnetic interaction (J = −22.8 cm⁻¹ for 1 and −26.0 cm⁻¹ for 2B).     

Keggin polyoxometalates-supported assembly of 2D supramolecular isomers: Synthesis, crystal structures and characteristics of two novel hybrid host-guest complexes

Two novel hybrid host-guest architectures based on metal-organic fragments and Keggin polyoxometalates, namely [α-Cu₁₂(trz)₈][PMo₁₂O₄₀] · H₂O (1) and [β-Cu₁₂(trz)₈][PMo₁₂O₄₀] · 2H₂O (2) (trz = 1,2,4-triazole), have been prepared under hydrothermal conditions and characterized by single-crystal X-ray diffraction (XRD), elemental analysis, powder XRD, ESR, FT-IR, UV-Vis, and thermogravimetric analysis (TGA). The [Cu₁₂(trz)₈]⁴⁺ hosts in compounds 1 and 2 are two-dimensional (2D) supramolecular isomers, which present 4⁴ topology based on Cu₄(trz)₄ cyclic units and 6³ topology based on Cu₃(trz)₃ cyclic units, respectively. The metalmacrocyclic Cu₈(trz)₈ and Cu₉(trz)₉ rings represent the largest examples in the coordination chemistry of 1,2,4-triazole. 2D metal-organic fragments and Keggin anions both are connected via hydrogen bonds and Cu?O short contacts to form interesting 3D host-guest architectures of 1 and 2.     

Hydrothermal synthesis, crystal structures and properties of new Fe, Co, Ni, and Zn complexes with 6-quinolinecarboxylate: Interplay of coordinative and noncovalent interactions

Reactions of Fe^II, Co^II, Ni^II, and Zn^II salts with 6-quinolinecarboxylic acid (HL) under the hydrothermal conditions afford three monomeric complexes [M(L)₂(H₂O)₄] (M = Fe^II for 1, Co^II for 2, and Ni^II for 3) and a 1-D polymeric species {[Zn(L)₂(H₂O)] · H₂O}_n (4). The crystal structures of the ligand HL and these four complexes have been determined by using the X-ray single-crystal diffraction technique. The results suggest that complexes 1-3 are isostructural, displaying novel 3-D pillar-layered networks through multiple intermolecular hydrogen bonds, whereas in coordination polymer 4, the 1-D comb-like coordination chains are extended to generate a hydrogen-bonded layer, which is further reinforced via aromatic stacking interactions. Solid-state properties such as thermal stability and fluorescence emission of the polymeric Zn^II complex 4 have also been investigated.     

3D hydrogen bonded heteronuclear Co, Ni, Cu and Zn aqua complexes derived from dipicolinic acid

The heteronuclear water-soluble and air-stable compounds [M(H₂O)₅M′(dipic)₂] · mH₂O (M/M′ = Cu^II/Co^II (1), Cu^II/Ni^II (2), Cu^II/Zn^II (3), Zn^II/Co^II (4), Ni^II/Co^II (5), m = 2-3; H₂dipic = dipicolinic acid) have been prepared by self-assembly synthesis in aqueous solution at room temperature, and characterized by IR, UV-Vis and atomic absorption spectroscopies, elemental and X-ray diffraction single crystal (for 1 and 2) analyses. 1-5 represent the first examples of heteronuclear dipicolinate compounds with 3d metals. Extensive H-bonding interactions involving all aqua ligands, dipicolinate oxygens and lattice water molecules further stabilize the dimetallic units by linking them to form three-dimensional polymeric networks.     

Hydrogen-bonding assemblies constructed from metalloligand building blocks and H2O

New hydrogen-bonding assemblies were synthesized from the reaction of a metalloligand, [Cu(2,4-pydca)₂]²⁻ (L^Cu) (2,4-pydca = 2,4-pyridinedicarboxylate), with a Fe^II ion or an imidazole in an aqueous medium and crystallographically characterized. The obtained compounds, [Fe(H₂O)₆][Cu(2,4-pydca)₂] (1) and [Cu(2,4-pydca)(imidazole)₂] · 2H₂O (2), have metalloligand dimer units, [Cu₂(2,4-pydca)₄]⁴⁻ and [Cu₂(2,4-pydca)₂(imidazole)₄], respectively, each of which assembles by π-π (1) and hydrogen-bonding (2) interactions to form 1-D metalloligand arrays. The 1-D metalloligand arrays are linked by rich hydrogen-bonding interactions via H₂O molecules.     

Novel Cu, Co and Pb supramolecular networks of pyridine-2,6-dicarboxylate (pydc) in cooperation with a bent dipyridyl spacer via coordinative, hydrogen-bonding and aromatic stacking interactions

Reaction of M(OAc)₂ (M^II = Cu^II for 1, Co^II for 2, and Pb^II for 3) with pyridine-2,6-dicarboxylic acid (H₂pydc) in presence of a dipyridyl spacer 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (bpo) affords three novel metal-organic supramolecular networks [Cu₂(bpo)(pydc)₂(H₂O)₃] · 2.75H₂O(1), [Co(bpo)(pydc)(H₂O)₂] · (H₂O) (2) and [Pb(pydc)]_n (3), which have been structurally determined by single-crystal X-ray diffraction. The dimeric Cu-pydc coordination framework bridged by a bpo spacer in 1 is hydrogen-bonded to four others to result in a two-dimensional (2-D) sheet array. The neutral monomeric molecules in 2 have an ordered 3-D stacking stabilized via hydrogen bonds and significant π-π interactions in the lattice, possessing large porous channels with the inclusion of guest solvates. In coordination polymer 3, the Pb^II ion takes the unusual distorted capped trigonal prismatic geometry (PbNO₆) and each pydc dianion binds to four Pb^II centres to form a 2-D infinite network. The thermal stabilities of these complexes have also been investigated.     

Robust anionic building blocks [M(malonate)2(H2O)2] for crystal engineering of inorganic-organic hybrid materials

One-pot reactions of transition metal (Cu^II, Ni^II, Co^II, or Cd^II) salt with malonic acid (H₂mal) in the presence of mesocyclic diamine generate three supramolecular complexes and a coordination polymer. [Cu(mal)₂(H₂O)₂](H₂O)₂(H₂DACH) (1) and [M(mal)₂(H₂O)₂](H₂DACO) (M = Ni for 2, and Co for 3) are ion-pair products and managed by charge-assistant noncovalent interactions (DACO = 1,5-diazacyclooctane, and DACH = 1,4-diazacycloheptane). In these structures, the similar mononuclear [M(mal)₂(H₂O)₂]²⁻ building blocks are connected by hydrogen bonds to form 2D networks (with the aid of one lattice water in the case of 1), which are further extended by the cationic diamine components to yield 3D pillar-layered solids. While [Cd(mal)(H₂O)₂]_n (4) is a neutral polymeric complex, in which the similar [Cd(mal)₂(H₂O)₂]²⁻ subunits are propagated by additional Cd-O coordinative forces to result in the final 2D layer.     

Transition metal complexes based on pyridine ligand containing both bis(2-pyridyl) and 1,3-dithiole-2-ylidene units: Syntheses, structures, and magnetic studies

Two new mononuclear spin-crossover iron(II) complexes, [FeL₂(NCS)₂] · H₂O (1) and [FeL₂(NCSe)₂] (2), have been synthesized from the reaction of the versatile ligand 4,5-bis(2-cyanoethylthio)-2-bis(2-pyridyl)methylene-1,3-dithiole (L), Fe(ClO₄)₂, and KNCX (X = S/Se). Reactions of L with Cu^II or Co^II salts afford one mononuclear complex [CuL(hfac)₂] · CH₃OH (hfac = hexafluoroacetylacetonate) (3), one dinuclear complex [(CuLCl)₂(μ-Cl)₂] · CH₃OH (4), and two 1D chain species, [CuL₂]_n(BF₄)_2n (5) and [CoL₂]_n(ClO₄)_2n · 2nCH₂Cl₂ (6). The crystal structures of complexes 1 and 3-6 have been determined by X-ray crystallography. Short intermolecular S?S contacts between neighboring 1D arrays are observed in 5 and 6, which lead to the formation of the 2D structure. The magnetic properties are studied, and antiferromagnetic couplings between the Cu^II centers across the chloride bridges have been found in 4 (J = 2.04 cm^-1). Spin-crossover behaviors between high and low spin states are observed at T_1/2 = 80 K for 1 and T_1/2 = 300 K for 2, respectively.     

Synthesis, crystal structure, and properties of supramolecular Cu, Zn, and Cd complexes with Salen-type bisoxime ligands

Three new supramolecular complexes, [Cu(L¹)H₂O]_n (1), [Zn(L²)(H₂O)₂]_n (2), and [Cd(L²)(H₂O)₂]_n (3), have been synthesized and characterized by FT-IR spectra, fluorescence spectra, and thermal analyses. And the structures of complexes 1-3 have been elucidated by X-ray analyses. Complex 1 is square pyramidal geometry with an unusually long bond (2.262 Å) from penta-coodinated Cu^II center to the oxygen atom of the apical coordinated water molecule. Molecules are linked by hydrogen bonding between the coordinated water and the phenolic oxygen atoms of adjacent molecules, thus formed a self-assembling continual zigzag chain supramolecular structure. The crystal structure of complex 2 (or 3) has indicated that the complex consists of one Zn^II (or Cd^II) atom, one L²⁻ unit and two coordinated water molecules, the coordination number of the Zn^II (or Cd^II) atom is six, and formed an infinite metal-water chain supramolecular structure by intermolecular hydrogen bonds and π-π stacking of neighboring benzene rings. Meanwhile, the thermal and photophysical properties of the resulted complexes have also been discussed.     

Coordination polymers of manganese(II) and cobalt(II) of a flexible tetradentate pyridine amide ligand: 1D zigzag network and non-covalent interactions

Synthesis and crystal structure of two coordination polymers of composition [Mn^II(H₂bpbn)_1.5][ClO₄]₂ · 2MeOH · 2H₂O (1) and [Co^II(H₂bpbn)(H₂O)₂]Cl₂ · H₂O (2) [H₂bpbn = N,N′-bis(2-pyridinecarboxamido)-1,4-butane], formed from the reaction between [Mn(H₂O)₆][ClO₄]₂/CoCl₂ · 4H₂O with H₂bpbn in MeCN, are described. In 1 each Mn^II ion is surrounded by three pyridine amide units, providing three pyridine nitrogen and three amide oxygen donors. Each Mn^II center in 1 has distorted MnN₃O₃ coordination. In 2 each Co^II ion is coordinated by two pyridine amide moieties in the equatorial plane and two water molecules provide coordination in the axial positions. Thus, the metal center in 2 has trans-octahedral geometry. In both 1 and 2, the existence of 1D zigzag network structure has been revealed. Owing to π-π stacking of pyridine rings from adjacent layers 1 forms 2D network; 2 forms 2D and 3D network assemblies via N-H?Cl and O-H?Cl secondary interactions. Both the metal centers are high-spin.     

Four copper(II) coordination polymers with a tetrachlorinated benzenedicarboxylate ligand: Solvent effect on diversiform supramolecular arrays

To further investigate the solvent effect on the structures of coordination polymers, a series of polymeric Cu^II complexes have been synthesized and characterized by single-crystal diffraction through combining of 2,3,5,6-tetrachloro-1,4-benzenedicarboxylic acid (H₂BDC-Cl₄) with Cu^II perchlorate. The products including {[Cu(BDC-Cl₄)(py)₃] · H₂O}_n (py = pyridine) (1), {[Cu(BDC-Cl₄)(dioxane)(H₂O)₂] · dioxane}_n (2), and {[Cu₂(BDC-Cl₄)₂(DMF)₄] · 2G}_n (G = MeOH in 3 and G = EtOH in 4) have been obtained in different mixed solvents systems. With the change of the solvent system from pyridine/H₂O (1:1) into dioxane/H₂O (1:1), the infinite 1-D Cu^II-BDC-Cl₄ chain motif in 1 is tuned into the 2-D (4,4) layered structure in 2 with the coordination of dioxanes to copper atoms. When the solvent system is changed into DMF/MeOH (1:1), then into DMF/EtOH (1:1), similar 1-D Cu^II-BDC-Cl₄ double chains are afforded in 3 and 4 with different solvents inclusion. Moreover, the judicious choice of binding-guests leads to numerous coordination geometries of Cu^II centers and final dissimilar supramolecular lattices of 1-4 from 1-D to 3-D via robust hydrogen-bonding interactions. The spectroscopic, thermal, and fluorescent properties of 1-4 have also been investigated.     

Metal-directed assembly of 1-D and 2-D coordination polymers with fluconazole and dicyanamide co-ligand

The coordination chemistry of a flexible poly(triazolyl)alkane derivative, fluconazole (HFlu), with a series of transition metal ions and dicyanamide (dca) anionic co-ligand has been explored to afford six new metal-organic coordination polymers. Complexes [M(HFlu)₂(dca)₂]_n (M = Mn^II for 1, Fe^II for 2, Co^II for 3, Zn^II for 5, and Cd^II for 6) have the isostructural 1-D double-chain array via bridging fluconazole, whereas [Cu₃(Flu)₂(dca)₄(CH₃OH)₂]_n (4) shows an unusual 2-D layered metal-organic framework with dimeric Cu^II subunits. Notably, both types of coordination patterns are extended into distinct 3-D supramolecular networks via hydrogen-bonding interactions. This result indicates that the choice of metal ion has a significant effect on these polymeric structures as well as the binding modes of the ligands, which is discussed in detail. The Zn^II and Cd^II complexes 5 and 6 display similar fluorescent emissions at 260 nm in the solid state, which essentially are intraligand transitions.     

Polynuclear nickel (II) and copper (II) complexes of hexaazamacrocycles incorporating pairs of diethylenetriamine subunits separated by aromatic spacers

A series of Ni(II) and Cu(II) complexes of the hexaaza macrocycles, 3,6,9,17,20,23-hexaazatricyclo[23.3.1.1^11,15]triaconta-1(29),11(30),12,14,25,27-hexaene (L¹) and 3,6,9,16,19,22-hexaazatricyclo[22.2.2.2^11,14]triaconta-1(26),11(29),12,14(30),24(28),25-hexaene (L²), have been prepared and the crystal structures determined for [Ni₂L¹(O₂CCH₃)₂(H₂O)₂](ClO₄)₂ (1), [Ni₂L²(DMF)₆](ClO₄)₄ · 2H₂O (2), {[Cu₂L²Br(O₂CCH₃)](ClO₄)₂}_n (3), [Cu₂L²(μ-CO₃)(H₂O)₂]₂(ClO₄)₄ · 8H₂O (4), [Cu₂L²(O₂CCH₃)₂](BF₄)₂ (5), and [Cu₂L¹(μ-imidazolate)Br]₂Br₄ · 6H₂O (6). In these complexes, two metal centers are bound per ligand; in 1 and 3-6, the N₃ subunits of L¹ or L² coordinate meridionally to the metal centers, whilst in 2, each N₃ subunit in L² adopts a facial mode of coordination. The binuclear cations in 1 and 2 have chair-like conformations, with the distorted octahedral Ni(II) coordination spheres completed by terminal water and a bidentate acetate ligand in 1 and three DMF ligands in 2. The Cu(II) centers in 3-6 generally reside in square planar environments, although a weakly binding ligand enters the coordination sphere in some cases, generating a distorted square pyramidal geometry. The binuclear [Cu₂L²]⁴⁺ units in 3, 4 and 5 adopt similar bowl-shaped conformations, stabilized by H-bonding interactions between pairs of amine groups from L² and a perchlorate or tetrafluoroborate anion. In 3, the binuclear units are linked through acetate groups, bridging in a syn-anti fashion, to produce a zig-zag polymeric chain structure, whilst 4 incorporates a tetrameric cation consisting of two binuclear units linked via a pair of carbonate bridges. Compound 6 features an imidazolate bridge between the two Cu(II) centers bound by L¹. Pairs of [Cu₂L¹(μ-imidazolate)]³⁺ units are then weakly linked through a pair of bromide anions.     

A new 3D transition-metal complex-templated framework based on Wells-Dawson polyoxometalate and copper(I)-pyrazine moieties

A new Wells-Dawson polyoxometalate-based compound, [Cu^II(2,2′-bipy)₂(H₂O)]₃[Cu^I₆(pz)₆(P₂W₁₈O₆₂)₂] (2,2′-bipy = 2,2′-bipyridine, pz = pyrizine) (1), has been hydrothermally synthesized and characterized by routine physical methods. Compound 1 exhibits a [Cu^II(2,2′-bipy)₂(H₂O)]²⁺ complex-templated 3D (3,4)-connected framework with the topology of (6³)(6²8⁴), which is built up by the cross-linking of porous P₂W₁₈-Cu layers and Cu^I-pz chains with Cu2 atoms as intersections. The transition-metal complex cation [Cu^II(2,2′-bipy)₂(H₂O)]²⁺ acts not only as a template locating in the voids of inorganic layers, but also as a charge-balance complex to make the 3D structure more steady. The electrochemistry property of compound 1 has also been discussed.     

Construction of 1-2D Cu(or Cu) metal-organic architectures with metal thiocyanates and bipyridyl spacers: Syntheses, structures, and thermal properties

Three new coordination polymers based on IB metal thiocyanates, [Cu^II(NCS)₂(DMSO)₄(meso-dpb)]_n (1), (2), [Cu^I(NCS)(pia)]_n (3) (dpb = 2,3-di(4-pyridyl)-2,3-butanediol, bpp = 1,3-bis(4-pyridyl)propane, pia = N,N′-(1,2-phenylene)diisonicotinamide), have been synthesized by the pre-assembly method and characterized by X-ray crystallography. In 1, Cu^II cations are bridged by meso-dpb ligands to form a one-dimensional (1D) linear chain. Compound 2 consists of 2D undulated layers of (4, 4) topology that show twofold parallel interpenetration. In the case of 3, the M^I center adopts tetrahedral coordination geometry and the 2D networks are formed by organic ligand with “folding ruler-shaped” NCS⁻-M chains. The thermal properties of 1-3 were also investigated.