Structural Diversity of Metallosupramolecular Assemblies from Cu(phen)2+ (phen = 1,10‐Phenanthroline) Building Blocks and 4,4′‐Bipyridine

Attempts to crystal engineer metallosupramolecularcomplexes from Cu(phen)²⁺ building blocks and the prototypical,rod‐like, exo‐bidentate ligand 4,4′‐bipyridine (4,4′‐bipy) by layering techniques are described. Reactions of Cu(phen)²⁺ (phen = 1,10‐phenanthroline) with 4,4′‐bipy in the presence of NO₃^– counterions yielded two distinct, discrete, dinuclear, C_i symmetric, dumbbell‐typecomplexes, [{Cu(NO₃)₂(phen)}₂(4,4′‐bipy)] ( 1 ) and [{Cu(NO₃)(phen)(H₂O)}₂(4,4′‐bipy)](NO₃)₂ ( 2 ), depending upon the mixture of solvents used for crystallization. In compound 1 , a mono‐ and a bidentate nitrato group coordinate to Cu²⁺, whereas in 2 the monodentate nitrato groups are replaced by aqua ligands, which introduce additional hydrogen‐bond donor functionality to the molecule. The crystal structure of 1 was determined by single‐crystal X‐ray analysis at 296 and 110 K. Upon cooling, a disorder‐order transition occurs, with retention of the space group symmetry. The crystal structure of 2 at room temperature was reported previously [Z.‐X. Du, J.‐X. Li, Acta Cryst. 2007 , E63, m2282]. We have redetermined the crystal structure of 2 at 100 K. A phase transition is not observed for 2 , but the low temperature single‐crystal structure determination is of significantly higher precision than the room temperature study. Both 1 and 2 are obtained phase‐pure, as proven by powder X‐ray diffraction of the bulk materials. Crystals of [Cu(phen)(CF₃SO₃)₂(4,4′‐bipy) · 0.5H₂O]_n ( 3 ), a one‐dimensional coordination polymer, were obtained from [Cu(CF₃SO₃)₂(phen)(H₂O)₂] and 4,4′‐bipy. In 3 , Cu(phen)²⁺ corner units are joined by 4,4′‐bipy via the two vacant cis sites to form polymeric zig‐zag chains, which are tightly packed in the crystal. Compounds 1 – 3 were further studied by infrared spectroscopy.     

Novel Copper(II) Thiodibenzoic Acid Coordination Polymers by in situ Extrusion of Sulfur from 2,2′‐Dithiodibenzoic Acid and the Unique Oxidation of Disulfide to Sulfate

Slow diffusion reaction of 2,2′‐dithiodibenzoic acid (dtdb) with CuCl₂ in the presence of N‐donor ligands results in the formation of different coordination polymers where both S–S and C–S scission and oxidation of S is observed. X‐ray diffraction analysis of [Cu(tdb)(phen)(H₂O)]₂ · 2H₂O.2DMF] ( 1 ), [Cu(tdb)(py)₂(H₂O)]₂ ( 3 ), and [Cu(tdb)(bipy)(H₂O)]₂ · 0.5H₂O ( 4 ) (tdb = thiodibenzoic acid, phen = phenanthroline, py = pyridine, bipy = 2,2′‐bipyridine) show that the metal ions are coordinated to the carboxylate oxygen atoms of the in situ generated tdb ligand in a monodenate fashion. In [Cu(phen)(SO₄)₂(H₂O)₂]_n ( 2 ) and [Cu(bipy)(SO₄)₂(H₂O)₂]_n ( 5 ), the sulfur is oxidized to sulfate ions prior to coordination with the metal. Complex 1 has a dimeric structure with π–π interactions between the phen ligands, whereas 3 and 4 form 1D polymeric chains.     

New Examples of Metal Coordination Architectures of 3,3′,4,4′‐Biphenyltetracarboxylic Acid – Syntheses,Crystal Structures,and Physical Properties

Four new metal‐organic frameworks [Cu₂(2,2′‐bipy)₂(ox)(H₂O)₂]·(H₂bptc) ( 1 ), [Cu(bptc)_0.5(phen)(H₂O)]·H₂O ( 2 ), Co₂(bptc)(bmb)_1.5 ( 3 ) and [Cd₂(bptc) (bmb)]·3H₂O ( 4 ) (H₄bptc = 3,3′,4,4′‐biphenyltetracarboxylic acid, ox = oxalate, phen = 1,10‐phenanthroline, 2,2′‐bipy = 2,2′‐bipyridine and bmb = 4,4′‐bis((1H‐imidazol‐1‐yl)methyl)biphenyl), were obtained by reactions of the corresponding metal salts with H₄bptc and N‐containing auxiliary ligands and their structures were determined by single‐crystal X‐ray diffraction. The results reveal that 1 has a 0‐D structure consisting of discrete ionic entities, while 2 features a 1‐D ladder structure. Additionally, there exist π‐π stacking and intermolecular hydrogen‐bonding interactions in 1 and 2 , respectively, forming 3‐D supramolecular structures. In 3 ‐ 4 , undulating 2‐D metal‐bptc layer structures are formed with two different coordination modes of bptc carboxylate groups, respectively, which are further extended by bmb into 3‐D structures. Magnetic properties of 1 and 3 have been studied. The photoluminescence property of 4 has also been investigated. Moreover, nonlinear optical measurements showed that 4 displayed a second‐harmonic‐generation (SHG) response of 0.7 times of that for urea.     

Syntheses,structures, and properties of four coordination compounds constructed from asymmetric semi-rigid V-shaped multicarboxylate ligand

Four new compounds, [Mn(HL)(phen)₂(H₂O)] (1), [Ni(HL)(phen)₂(H₂O)] (2), [Zn(HL)(4,4′-bipy)_1.5(H₂O)] _n ?·?2nH₂O (3) and [Zn₂(HL)₂(H₂O)₆] (4), have been synthesized from an asymmetric semi-rigid V-shaped multicarboxylate 4-(4-carboxy-phenoxy)-phthalic acid (H₃L) with 1,10-phenanthroline (phen), or 4,4′-bipyridine (4,4′-bipy) as auxiliary ligands. Single-crystal X-ray diffraction analysis reveals that 1, 2 and 4 have 0-D structures with 3-D supramolecular frameworks formed by intermolecular hydrogen bonds. Compound 3 shows a 1-D infinite ribbon bridged by 4,4′-bipy, which further forms a 3-D supramolecular architecture by π–π stacking interactions and hydrogen bonds. Thermal stabilities of 1–4 and luminescence properties of 3 and 4 have also been investigated.     

Simultaneous Presence of Both Open Metal Sites and Free Functional Organic Sites in a Noncentrosymmetric Dynamic Metal–Organic Framework with Bimodal Catalytic and Sensing Activities

Assimilation of open metal sites (OMSs) and free functional organic sites (FOSs) with a framework strut has opened up a new route for the fabrication of novel metal–organic materials, thereby providing a unique opportunity to explore their multiple functionalities. A new metal–organic framework (MOF), {[Cu(ina)₂(H₂O)][Cu(ina)₂(bipy)]?2 H₂O}_n ( 1 ) (ina=isonicotinate, bipy=4,4′‐bipyridine), has been synthesized and characterized. Complex 1 is crystallized in the orthorhombic noncentrosymmetric space group Aba2 and consists of two different 2D coordination polymers, [Cu(ina)₂(H₂O)]_n and [Cu(ina)₂(bipy)]_n, with entrapped solvent water molecules. Hydrogen‐bonding interactions assemble these two different 2D coordination layers in a single‐crystal structure with interdigitation of pendant 4,4′‐bipy from one layer into the groove of another. Upon removal of guest molecules, 1 undergoes a structural transformation in single‐crystal‐to‐single‐crystal fashion with expansion of the effective void space. Each metal center is five‐coordinated and thus can potentially behave as an OMS, and the free pyridyl groups of pendant 4,4′‐bipy moieties and free ? C?O groups can act as free FOSs. Thus, owing to presence of both OMSs and free FOSs, the framework exhibits multifunctional properties. Owing to the presence of OMSs, the framework can act as a Lewis acid catalyst as well as a small‐molecule sensor material, and in a similar way, owing to the presence of free FOSs, it performs as a Lewis base catalyst and a cation sensor material. Furthermore, owing to noncentrosymmetry with large polarity along a particular direction, it shows strong second‐harmonic generation/nonlinear optical (SHG‐NLO) activity.     

Formation and Structural Characterization of Metal Complexes derived from Thiosalicylic Acid

The formation and structural aspects of some metal complexes of thiosalicylic acid (TSA) were studied. The μ‐bridging tetra‐coordinated Ru complex, [Ru(C₆H₄(CO₂)(μ‐S)(H₂O)]₂ ( 1 ) was formed by hydrothermal reaction of TSA with RuCl₃. The complexes [M(dtdb)(phen)(H₂O)]_n ( 2 – 4 ) (M = Zn^II, Co^II, Ni^II, dtdb = 2,2′‐dithiodibenzoate anion, phen = 1,10‐phenanthroline) were obtained by the slow diffusion technique and the in situ S–S bond formation was confirmed by elemental, spectral and X‐ray analysis. Reaction of TSA with CuCl₂ and 2,2′‐bipyridine (bipy) under the slow diffusion technique yielded the dimer [Cu(tdb)(bipy)] ( 5 ) (tdb = thiodibenzoic acid), where the in situ generation of 2,2′‐thiodibenzoic acid was observed.     

Synthesis,Structures, and Fluorescent Properties of Three Cobalt‐Based Coordination Polymers with a Rigid Tripodal Carboxylate Ligand

Three cobalt(II) coordination polymers, [Co₂(tatb)₂(2,2′‐bipy)₂ (H₂O)₂ · DMA · 2H₂O] ( 1 ), [Co₂(tatb)₂(1,10‐phen)₂(H₂O)₂ · 2H₂O] ( 2 ) and [Co(tatb)(1,3‐dpp) · H₂O] ( 3 ) (H₃tatb = 4,4′,4′′‐(1,3,5‐triazine‐2,4,6‐triyl)tribenzoic acid; 2,2′‐bipy = 2,2′‐bipyridyl; 1,10‐phen = 1,10‐phenanthroline; 1,3‐dpp = 1,3‐bis(pyridin‐4‐yl)propane), were synthesized solvothermally and characterized by single‐crystal and powder X‐ray diffraction (PXRD), as well as IR spectroscopy. Complexes 1 and 2 exhibit 1D double‐chain structures, which further connect into interesting 3D networks by hydrogen bond and strong π–π interactions. Complex 3 possesses 2D 4⁴‐sql topology, which is packed parallel in an AA fashion. Moreover, thermal stability properties and photoluminescence properties of 1 , 2 and 3 were also investigated.     

Auxilary Ligand Directed Zinc(II) Metal‐Organic Frameworks with Different Topological Networks

By altering auxiliary N‐donor ligands, two Zn^II compounds, [Zn₃(HL)₂(4,4′‐bipy)₃]_n ( 1 ) and [Zn₄(L)₂(bpp)]_n ( 2 ) (H₄L = 3‐(2′,4′‐dicarboxylphenoxy)phthalic acid, 4,4′‐bipy = 4,4′‐bipyridine, and bpp = 1,3‐bis(4‐pyridyl)propane), were obtained under hydrothermal conditions. Structural analyses revealed that compound 1 features a trinodal (3,4,4)‐connected 3D topological framework, and compound 2 displays a (3,8)‐connected 3D pillar‐layered framework with a tfz‐d topology. Furthermore, the thermal stabilities and the luminescent properties of compounds 1 and 2 were investigated.     

Structural Variability and Gas Adsorption Properties of Coordination Polymers Constructed with Aromatic Multicarboxylic and Bidentate Ligands

The self‐assembly reactions of transition metal ions and 1,3,5‐benzenetricarboxylic acid (H₃btc) in the presence of auxiliary aromatic bidentate ligands 1,10‐phenanthroline (1,10‐phen) or 4,4′‐bipyridine‐N,N′‐dioxide (4,4′‐bpdo) have isolated four coordination polymers [Co₁₈(btc)₁₀(H₂O)₆(OH)₆(1,10‐phen)₆] · 14H₂O · 3DMF ( 1 ) and [M₃(btc)₂(H₂O)₄(4,4′‐bpdo)] · 2H₂O · 2DMF [M = Co ( 2 ), Mn ( 3 ), Ni ( 4 )]. Single‐crystal X‐ray diffraction analysis revealed that the M₃ clusters in the structure of 1 – 4 are connected by hydroxyl group oxygen atoms (or oxygen atoms from 4,4′‐bpdo ligands) and carboxyl groups to generate a three‐dimensional framework. The network of final assemblies can be adjusted by varying the type of auxiliary ligands (1,10‐phen, 4,4′‐bpdo). In addition, the gas adsorption properties of 2 are also investigated.     

Solvothermal Synthesis,Crystal Structure,and Photocatalytic H2 Evolution of two CuII Coordination Polymers Based on Keggin Polyoxotungstates

Two new Cu^II coordination polymers based on α‐Keggin polyoxotungstates, [Cu₂(dpa)₂(H₂O)₂(GeW₁₂O₄₀)] · 0.5CH₃COOH ( 1 ) and [Hdpa][Cu₂(dpa)₂(4,4′‐bipy)(H₂O)₂(PW₁₀V₂O₄₀)] ( 2 ) (dpa = 2,2′‐dipyridylamine, 4,4′‐bipy = 4,4′‐bipyridine), were obtained by solvothermal reactions in glacial acetic acid and characterized by elemental analysis, IR spectroscopy, TG analysis, X‐ray powder diffraction, and single‐crystal X‐ray diffraction. Compound 1 exhibits a 1D two‐rowed chain constructed from [GeW₁₂O₄₀]^4– anions coordinated with [Cu(1)(dpa)]²⁺ and [Cu(2)(dpa)(H₂O)₂]²⁺ fragments by four terminal oxygen atoms. Compound 2 exhibits a 2D layered structure constructed from [PW₁₀V₂O₄₀]^5– anions coordinated with [Cu(dpa)(4,4′‐bipy)_0.5(H₂O)]²⁺ fragments by four terminal oxygen atoms. Furthermore, the electrochemical properties of 1 and the photocatalytic hydrogen production of 1 and 2 were investigated.     

Poly[[diaqua‐μ‐4,4′‐bipyridine‐dinitratodi‐μ‐l‐tyrosinato‐dicopper(II)]: a chiral two‐dimensional coordination polymer

The title compound, [Cu₂(C₉H₁₀NO₃)₂(NO₃)₂(C₁₀H₈N₂)(H₂O)₂]_n, contains Cu^II atoms and l ‐tyrosinate (l ‐tyr) and 4,4′‐bipyridine (4,4′‐bipy) ligands in a 2:2:1 ratio. Each Cu atom is coordinated by one amino N atom and two carboxylate O atoms from two l ‐tyr ligands, one N atom from a 4,4′‐bipy ligand, a monodentate nitrate ion and a water molecule in an elongated octahedral geometry. Adjacent Cu atoms are bridged by the bidentate carboxylate groups into a chain. These chains are further linked by the bridging 4,4′‐bipy ligands, forming an undulated chiral two‐dimensional sheet. O—H...O and N—H...O hydrogen bonds connect the sheets in the [100] direction. This study offers useful information for the engineering of chiral coordination polymers with amino acids and 4,4′‐bipy ligands by considering the ratios of the metal ion and organic components.     

Fluorescent Properties of Three Carboxyarylphosphonate Polymers with Unusual Polynuclear Zinc(II) Units

Three novel carboxyarylphosphonate polymers {[Zn₂(PCP)(H₂PCP)(phen)₂] · H₂O}_n ( 1 ), [Zn(HPCP)(4,4′‐bipy)]_n ( 2 ), and [Zn₃(MCP)₂(2,2′‐bipy)]_n ( 3 ) [PCP^3– = p‐O₂C(C₆H₄)CH₂PO₃^3–, MCP^3– = m‐O₂C(C₆H₄)CH₂PO₃^3– and phen = phenanthroline] were synthesized and characterized by single‐crystal X‐ray diffraction. Compound 1 features a butterfly‐shaped dimer consisting of [Zn₄P₄O₁₀] tetranuclear units, which are further linked by hydrogen bonds and π–π stacking interactions into a 3D supramolecular framework. In 2 , there is an infinite P–O–Zn inorganic 2D (4,4) layer with the phosphonate moieties of HPCP^2– and unidentate 4,4′‐bipy ligands vertically sticking out. As for 3 , the novel [Zn₆P₄O₁₂] hexanuclear units with “chair“ conformation are tetrahedrally bridged by eight MCP^3– to generate a 2D double‐layer, in which the windows are occupied by 2,2′‐bipy molecules. Additionally, 2D correlation analysis of FTIR with thermal perturbation of 3 were discussed. Compounds 1 – 3 exhibit intense solid state fluorescent emissions. Thermogravimetric analyses suggested the very high stability.     

Poly[diaquabis(μ‐4,4′‐bipyridine‐κ2N:N′)bis(ethane‐1,2‐diol)di‐μ‐sulfato‐dicopper(II)]

The title compound, [Cu₂(SO₄)₂(C₁₀H₈N₂)₂(C₂H₆O₂)₂(H₂O)₂]_n, contains two crystallographically unique Cu^II centres, each lying on a twofold axis and having a slightly distorted octahedral environment. One Cu^II centre is coordinated by two bridging 4,4′‐bipyridine (4,4′‐bipy) ligands, two sulfate anions and two aqua ligands. The second is surrounded by two 4,4′‐bipy N atoms and four O atoms, two from bridging sulfate anions and two from ethane‐1,2‐diol ligands. The sulfate anion bridges adjacent Cu^II centres, leading to the formation of linear ...Cu1–Cu2–Cu1–Cu2... chains. Adjacent chains are further bridged by 4,4′‐bipy ligands, which are also located on the twofold axis, resulting in a two‐dimensional layered polymer. In the crystal structure, extensive O—H...O hydrogen‐bonding interactions between water molecules, ethane‐1,2‐diol molecules and sulfate anions lead to the formation of a three‐dimensional supramolecular network structure.     

Hydrothermal Synthesis, Crystal Structures of Three New Metal (Ⅱ) Complexes with 1-Adamantaneacetic Acid

Three new complexes constructed by 1‐adamantaneacetic acid (HL), [Zn₂L₄]_n ( 1 ), [MnL₂(4,4′‐bipy)(H₂O)₂]_n· 2n(HL) ( 2 ) and MnL₂(2,2'‐bipy)(H₂O)₂ ( 3 ), have been hydrothermally synthesized. X‐ray single crystal diffraction analyses reveal that both 1 and 2 are infinite 1D chains along b axis. 2 and 3 have an octahedral coordination and show the supramolecular structures which are formed on the basis of the connectivity of intermolecular hydrogen bonds. The deprotonated L^? ligands coordinate the M(II) atoms with many coordination modes in the title complexes.     

Metal Derivatives of Thiosemicarbazones: Crystal and Mole­cular Structures of Mono‐ and Dinuclear Copper(II) Complexes with N1‐Subsitituted Salicylaldehyde Thiosemicarbazones

Reactions of copper(II) acetate with N¹‐subsitituted salicylaldehyde thiosemicarbazones [R¹R²C²=N³–N²H–C¹(=S)–N¹HR³;R¹ = 2‐HO–C₆H₄–, R² = H : R³ = Me (H₂L¹), Et (H₂L²)] are described. Copper(II) acetate was reacted with H₂L¹ and H₂L² ligands in the presence of polypyridyl co‐ligands, and this led to the formation ofmononuclear complexes, [Cu(κ³‐O, N, S‐L¹)(κ²‐N, N‐bipy)] ( 1 ),[Cu(κ³‐O, N, S‐L)(κ²‐N, N‐phen)] [L = L¹ ( 3 ), L² ( 4 )], [Cu(κ³‐O, N, S‐L)(κ²‐N, N‐tmphen)] [L =L¹ ( 5 ), L² ( 6 )] and a dinuclear complex, [Cu₂L²₂(bipy)] ( 2 ) (bipy = 2, 2′‐bipyridine, phen = 1, 10‐phenanthroline, tmphen = 3, 4, 7, 8‐tetramethyl‐1, 10‐phenanthroline). In dinuclear complex 2 , one ligand is O, N³,S‐chelating, while second is O, N³,S‐chelation‐cum‐N²‐bridging; and in all others thio‐ligands are O, N³,S‐chelating. The μ_eff values for the complexes lie in the range of 1.79–1.83 BM. Complexes 1 , 3 – 6 have square pyramidal arrangement, whereas complex 2 has two independent molecules in the crystal lattice, and each molecule has trigonal bipyramidal square planar (5:4) coordination pair. Complexes 2 , 4 , and 6 showed fluorescence properties.     

Synchronizing Substrate Activation Rates in Multicomponent Reactions with Metal–Organic Framework Catalysts

A study on the influence of the cation coordination number, number of Lewis acid centers, concurrent existence of Lewis base sites, and structure topology on the catalytic activity of six new indium MOFs, has been carried out for multicomponent reactions (MCRs). The new indium polymeric frameworks, namely [In₈(OH)₆(popha)₆(H₂O)₄]?3 H₂O ( InPF‐16 ), [In(popha)(2,2′‐bipy)]?3 H₂O ( InPF‐17 ), [In₃(OH)₃(popha)₂(4,4′‐bipy)]?4 H₂O ( InPF‐18 ), [In₂(popha)₂(4,4′‐bipy)₂]?3 H₂O ( InPF‐19 ), [In(OH)(Hpopha)]?0.5 (1,7‐phen) ( InPF‐20 ), and [In(popha)(1,10‐phen)]?4 H₂O ( InPF‐21 ) (InPF=indium polymeric framework, H₃popha=5‐(4‐carboxy‐2‐nitrophenoxy)isophthalic acid, phen=phenanthroline, bipy=bipyridine), have been hydrothermally obtained by using both conventional heating (CH) and microwave (MW) procedures. These indium frameworks show efficient Lewis acid behavior for the solvent‐free cyanosilylation of carbonyl compounds, the one pot Passerini 3‐component (P‐3CR) and the Ugi 4‐component (U‐4CR) reactions. In addition, InPF‐17 was found to be a highly reactive, recyclable, and environmentally benign catalyst, which allows the efficient synthesis of α‐aminoacyl amides. The relationship between the Lewis base/acid active site and the catalytic performance is explained by the 2D seven‐coordinated indium framework of the catalyst InPF‐17 . This study is an attempt to highlight the main structural and synthetic factors that have to be taken into account when planning a new, effective MOF‐based heterogeneous catalyst for multicomponent reactions.     

Hydrothermal Synthesis,Structural Characterization,Magnetic and Photoelectric Properties of Two Cobalt(II) Coordination Polymers

Two cobalt(II) coordination polymers, {[Co(μ‐4,4′‐bipy)(4,4′‐bipy)₂(H₂O)₂]·(OH)₃·(Me₄N)·4,4′‐bipy·4H₂O}_n ( 1 ) and {[Co(μ‐4,4′‐bipy)(H₂O)₄]·suc·4H₂O}_n ( 2 ) (4,4′‐bipy = 4,4′‐bipyridine, suc = succinate dianions), were hydrothermally synthesized and structurally characterized by X‐ray diffraction analysis, UV‐Vis‐NIR, and ICP. The main structure feature common to the both polymers is presence of the infinite linear chains, [Co(μ‐4,4′‐bipy)(4,4′‐bipy)₂(H₂O)₂]_n ( 1 ) and [Co(μ‐4,4′‐bipy)(H₂O)₄]_n ( 2 ), respectively. In 1 , the chains are further linked by the hydrogen‐bond and π‐π stacking interaction, producing extended layer structure. The 4,4′‐bipy molecules in 1 play three different roles. In 2 , the chains are linked into three‐dimensional network structure via complicated hydrogen bonding system. The variable temperature (2.0～300 K) magnetic susceptibility of 1 indicates a tendency of spin‐transition in the temperature range of 110 K to 22 K, which attributes to the transition of high‐spin to low‐spin from Co²⁺(d⁷) ion. Also, the result of surface photovoltage spectroscopy (SPS) reveals that the polymer 1 has significant photoelectric conversion property in the region of 300‐800 nm.     

Supramolecular Assembly of Double‐Stranded Chains,Helical Chains and Catenane‐like Layers with Flexible Ligands

Four new transition metal coordination polymers, [Co(bpndc)(phen)(H₂O)]_n ( 1 ), [Co₃(bpndc)₃(2,2′‐bpy)₂]_n·0.5n(i‐C₃H₇OH) ( 2 ), and [M(bpndc)(2,2′‐bpy)₂]_n (M = Zn, 3 ; Cu, 4 ; H₂bpndc = benzophenone ‐4,4′‐dicarboxylic acid; phen = 1,10‐phenanthroline; 2,2′‐bpy = 2,2′‐bipyridine) have been synthesized by the hydrothermal reactions and characterized by single crystal X‐ray diffraction, elemental analysis, and IR spectrum. Because of the introduction of different terminal auxiliary ligands, bpndc ligands in complexes 1 and 2 adopt different coordination modes. In complex 1 , bpndc ligands act as tridentate ligand and bridge Co^II ions into 1D double‐stranded chains; while complex 2 possesses 2D (4,4) grids, where bpndc ligands adopt tetradente and pentadentate modes. Two such grids interpenetrate to form a novel catenane‐like layer. Complexes 3 and 4 are isostructural. Bpndc ligands adopt tetradentate mode and bridge metal ions forming 1D helical chains.     

Three Novel Mixed‐ligand Cadmium(II) Sulfonates with Aza‐aromatic Skeltons as Co‐ligands

To survey the influence of aza‐aromatic co‐ligands on the structure of Cadmium(II) sulfonates, three Cd(II) complexes with mixed‐ligand, [Cd^II(ANS)₂(phen)₂] ( 1 ), [Cd^II(ANS)₂(2,2′‐bipy)₂] ( 2 ) and [Cd^II(ANS)₂(4,4′‐bipy)₂]_n ( 3 ) (ANS = 2‐aminonaphthalene‐1‐sulfonate; phen = 1,10‐phenanthroline; 2,2′‐bipy = 2,2′‐bipyridine; 4,4′‐bipy = 4,4′‐bipyridine) were synthesized by hydrothermal methods and structurally characterized by elemental analyses, IR spectra, and single crystal X‐ray diffraction. Of the three complexes, ANS consistently coordinates to Cd²⁺ ion as a monodentate ligand. While phen in 1 and 2,2′‐bipy in 2 act as N,N‐bidentate chelating ligands, leading to the formation of a discrete mononuclear unit; 4,4′‐bipy in 3 bridges two Cd^II atoms in bis‐monodentate fashion to produce a 2‐D layered network, suggesting that the conjugate skeleton and the binding site of the co‐ligands have a moderate effect on molecular structure, crystal stacking pattern, and intramolecular weak interactions. In addition, the three complexes exhibit similar luminescent emissions originate from the transitions between the energy levels of sulfonate anions.     

Chains of (4,4′‐bipyridyl)copper(I) bridged by dimolybdate units

The crystal structure of the title compound, poly­[bis‐[copper(I)‐μ‐(4,4′‐bipyridyl)‐N:N′]‐μ‐dimolybdato‐O:O′],[Cu₂(C₁₀H₈N₂)₂{Mo₂O₇}]_n, consists of {Mo₂O₇}^2? units (with the central O atom lying on twofold symmetry axes) and [Cu(4,4′‐bipy)]_nⁿ⁺ chains (bipy = bipyridyl); the chains are generated by a c‐glide‐plane operation. The {Mo₂O₇}^2? units are covalently bridged to two [Cu(4,4′‐bipy)]_nⁿ⁺ chains, forming a complex with a bridged double‐chain structure. The Cu—O and Cu—N distances are 2.191 (3) and 1.933 (3) Å, respectively.