Hydrogen Bonding and Iodine Bonding Interactions in Sustaining Two Coordination Polymers Base on Square Grids and Tetranuclear Cobalt Clusters

Two new coordination polymers [Co(H₂O)₂(bpy)₂]·2(Adi) (1) and [Co₄(OH)₂(Adi)₆(bpe)₂] (2) (HAdi = 4-amino-3,5-diiodobenzoic acid, bpy = 4,4′-bipyridine, bpe = 1,2-bis(4-pyridyl)ethylene) have been synthesized by methods of hydrothermal reactions and their crystal structures determined. In 1, the mononuclear Co atoms are linked by bpy ligands forming cationic two-dimensional square grids, which are connected by the intercalated Adi guest molecules through significant hydrogen-bonding interactions to give a three-dimensional supramolecular porous network with one-dimensional channels. 2 has a one-dimensional chain structure based on rhombic tetranuclear Co^II clusters, connected by bpe ligands. Through special I···I interactions, adjacent chains are extended into a three-dimensional supramolecular structure. The structure versatility indicates that the amino and iodo groups of Adi ligands play a crucial role in modulating the coordination polymers. A discussion of the crystal structures, thermal stabilities, as well as the noncovalent interactions of Adi molecules is provided. IR, elemental analysis and XRPD confirmed the phase purity of the bulk materials. Magnetic properties of 2 in the 300–2 K have been discussed, which reveal the occurrence of antiferromagnetic interactions between Co^II ions.     

Supramolecular assembly of three Ag(I) coordination polymers derived from flexible N-containing ligands and polycarboxylates: synthesis,structures, and catalytic properties

Three Ag(I) coordination polymers [Ag(L1)]·(H₃bptc)·H₂O (1), [Ag₂(L2)(oba)]·H₂O (2), and [Ag₂(L2)₂]·(H₂bptc) (3) [L1 = 1,4-bis(3,5-dimethylpyrazole)butane, L2 = 1,4-bis(2-methylbenzimidazole)butane, H₄bptc = 3,3′,4,4′-biphenyltetracarboxylic acid, H₂oba = 4,4′-oxybis(benzoic acid)] constructed from N-containing ligands with different flexibilities and organic carboxylates as co-ligands have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction analysis. All three complexes display 1D chain structures, which are further extended into 2D supramolecular networks via non-classical C–H···O hydrogen bonding interactions. The fluorescence and catalytic properties of the complexes 1–3 have been investigated in detail. Complexes 2 and 3 reveal promising catalytic activities for the degradation of methyl orange in a Fenton-like process.     

Hydrostable coordination polymers of a methyl-functionalized 4,4′-bipyridine ligand: structure,stability, magnetic and luminescent properties

The reactions of aromatic dicarboxylic acids and methyl-functionalized 4,4′-bipyridine ligands with metal salts under hydrothermal conditions generated four structurally diverse cobalt(II), zinc(II) and cadmium(II) coordination polymers, [Co(CH₃-BDC)(dmbpy)_0.5] _n (1), [Cd(OH-HBDC)₂(dmbpy)] _n (2), [Zn(NDC)(dmbpy)] _n , (3) and {[Cd(DBA)(dmbpy)_0.5]·2H₂O} _n (4) (CH₃–H₂BDC = 5-methylisophthalic acid, OH–H₂BDC = 5-hydroxyisophthalic acid, H₂NDC = 1,4-naphthalenedicarboxylic acid, H₂DBA = 4,4′-methylenedibenzoic acid, dmbpy = 2,2′-dimethyl-4,4′-bipyridine). All four complexes have been structurally characterized by X-ray crystallography. Complex 1 shows a 3D jsm topology structure with two 1D channels parallel to the a and b axes. Complex 2 has a zigzag chain in which the OH-HBDC ligands point alternately up and down. Complexes 3 and 4 show 2D (4,4) networks when the dinuclear metal centers and their ligands are regarded as nodes and linkers, respectively. Complex 3 also shows twofold interpenetration with 1D channels along the b axis. Two nets of complex 4 interlock in parallel, giving rise to a polycatenated layer (2D → 2D). Thermogravimetric and chemical stabilities, magnetic and luminescent properties of these complexes were investigated.     

Synthesis,crystal structures and photocatalytic properties of four silver(I) coordination polymers based on semirigid bis(pyrazole) and carboxylic acid co-ligands

Four Ag(I) coordination polymers, formulated as [Ag(L1)(tpa)_0.5] _n (1), {[Ag(L2)(ndc)_0.5]·0.5H₂ndc} _n (2), [Ag(L3)_0.5(ndc)_0.5] _n (3) and {[Ag(L3)]·H₃bptc} _n (4) (L1 = 4,4′-bis(pyrazole-1-ylmethyl)-biphenyl, L2 = 4,4′-bis(3,5-dimethylpyrazol-1-ylmethyl)-biphenyl, L3 = 1,4-bis(3,5-dimethylpyrazol-1-ylmethyl)benzene, H₂tpa = terephthalic acid, H₂ndc = 2,6-naphthalenedicarboxylic acid, H₄bptc = 3,3′,4,4′-biphenyltetracarboxylic acid), have been hydrothermally synthesized and structurally characterized. Complex 1 features the rare binodal (4,4)-connected 2D 4,4L10 topological network with a point symbol of {3²·4.6²·7}₂{3²·6²·7²}. Complex 2 has a folded ladder-like chain structure, which is further extended into a 3D supramolecular network via O–H···O hydrogen bonding and π···π stacking interactions. Complexes 3 and 4 both possess 1D zigzag chain structures. Complex 3 is further extended into a binodal (3,4)-connected network with the point symbol of {4.8⁴·10}{6²·8²}₂ by Ag···O weak interactions, while complex 4 is further connected through O–H···O hydrogen bonding and π···π interactions to afford a 2D supramolecular structure. The photoluminescence spectra and photocatalytic properties of these complexes for degradation of methylene blue and methyl orange are reported.     

Syntheses,crystal structures,and DNA binding and catalytic properties of two transition metal coordination polymers constructed from 5-aminoisophthalic acid and bis-benzimidazole ligands

Two mixed-ligand transition metal coordination polymers, {[Co(aip)(bbp)]·(H₂O)} _n (1) and {[Ni₂(aip)(Hbbop)₂]·(H₂O)₂} _n (2) (H₂aip = 5-aminoisophthalic acid, bbp = 1,3-bis(benzoimidazol-2-yl)propane, H₂bbop = 1,3-bis(benzimidazol-2-yl)-2-oxapropane), were synthesized and characterized by elemental analyses, IR spectra, single-crystal X-ray diffraction, and thermogravimetric analyses. Complex 1 has a 1D chain structure, while 2 has a 3-connected 2D network with (6³) topology. Both structures are further connected by hydrogen bonds and π–π stacking interactions to form the 3D supramolecular architectures. DNA binding and catalytic properties of the two complexes were investigated.     

Three cobalt(II) coordination polymers constructed from flexible bis(thiabendazole) and dicarboxylate linkers: crystal structures,fluorescence, and photocatalytic properties

Three Co(II) coordination polymers, namely, {Co(btbb)_0.5(ndc)(H₂O)}_n (1), {[Co(btbb)(bpdc)]·1.5H₂O}_n (2), and {[Co(btbp)₂(3-npa)]·2H₂O}_n (3) (btbb = 1,4-bis(thiabendazole)butane, btbp = 1,3-bis(thiabendazole)propane, H₂ndc = 2,6-naphthalenedicarboxylic acid, H₂bpdc = 4,4′-biphenyldicarboxylic acid and 3-H₂npa = 3-nitro phthalic acid) were synthesized under hydrothermal conditions. Their X-ray crystal structures show that complexes 1 and 2 both have 2D uninodal 3-connected hcb (honeycomb) structures. Complex 1 is further extended into a threefold interpenetrating 3D 4,4-connected mog (moganite) supramolecular architecture with the point symbol of {4.6⁴.8}₂{4².6².8²} by O–H···O hydrogen bonding interactions. Complex 2 shows a 3D supramolecular framework involving π···π stacking interactions. Complex 3 features a uninuclear structure, which is further assembled into an ordered 2D hydrogen-bonded-driven pattern with O–H···O and O–H···N hydrogen bonding interactions. The fluorescence spectra and photocatalytic properties of complexes 1–3 for degradation of methyl orange were investigated.     

Three silver(I) coordination polymers assembled from 2-sulfoterephthalic acid and N-donor ligands: syntheses, crystal structures, and luminescence properties

The reactions of silver nitrate with 2-sulfoisophthalic acid (H₃stp) in the presence of N-donor ligands produced three coordination polymers; [Ag₃(stp)(pyz)_0.5]_n (1), {[Ag₄(dpp)₄]·2(Hstp)·9H₂O}_n (2), and {[Ag(bpe)]₂[Ag₂(bpe)₂]₂·2(stp)·19H₂O}_n (3) [pyz = pyrazine, bpp = 1,2-bis(4-pyridyl)propane, bpe = 1,2-di(4-pyridyl)-ethylene]. The complexes have been characterized by single-crystal X-ray diffraction, physico-chemical, and spectroscopic methods. Single-crystal X-ray diffraction reveals that complex 1 is a 2D silver carboxylate-sulfonate layered structure, in which the 2D layers are further linked by the N-donor atoms of pyz ligands into a 3D supramolecular structure. Complex 2 is an infinite 1D chain arrangement with the [Ag₂(dpp)₂]²⁺ unit in which weak Ag···Ag or Ag···O interactions extend the chains into 2D structures. Complex 3 has a 3D supramolecular structure constructed by hydrogen bonding, π–π stacking, and Ag···O interactions to link the ligands, metal atoms, and water molecules together. The luminescence properties of the complexes were investigated.     

Synthesis,Crystal Structures and Magnetic Properties of Three New Polynuclear Cu(II) Complexes Based on the Methoxybenzoate Isomers

In this paper, self-assembly reactions of copper(II) ions, methoxybenzoate isomers and 2,2′-bipyridine yield two copper-oxygen polynuclear complexes: [Cu₂(bpy)₂(2-C₈H₇O₃)₃]·(2-C₈H₇O₃)·14H₂O 1, [Cu₄(bpy)₄(H₂O)(OH)₄]·4(3-C₈H₇O₃)·17H₂O 2, and a simple mononuclear complex [Cu(bpy)(H₂O)(4-C₈H₇O₃)₂] 3. (bpy = 2,2′-bipyridine, C₈H₇O₃ = methoxybenzoate ion). Single crystal X-ray diffraction analyses reval that compound 1 is a dinuclear copper(II) complex which bridged by three carboxylate groups, and 2 presents a discrete step-like tetra-nuclear copper Cu₄O₄ core. Compound 3 shows a square pyramidal mononuclear geometry. The magnetic susceptibility of complex 1 measured from 2 to 300 K, revealed an antiferromagnetic interaction between the Cu(II) ions. Furthermore, the results about IR spectra and thermal analyses were discussed.     

Syntheses,structures and properties of complexes of indole-3-propionic acid

Three complexes [Zn₂(IPA)₂(phen)₄](HIPA)₂(NO₃)₂·H₂O (1), {[Zn(IPA)₂(bipy)]·3H₂O}_n (2), and {[Mn(IPA)₂(bipy)(H₂O)]·2H₂O}_n (3) (HIPA = indole-3-propionic acid, phen = 1,10-phenanthroline, bipy = 4,4′-bipyridine) were synthesized and characterized by physico-chemical and spectroscopic methods. Complex 1 displays a zero-dimensional structure, whilst 2 and 3 show one-dimensional chains, which are linked into supramolecular networks through hydrogen bonding interactions and/or π···π stacking interactions. The luminescence properties of complexes 1 and 2 were investigated.     

Structure Modulation in Four New Coordination Polymers by In Situ Ligands Synthesis of Anthracene Derivatives and Various Auxiliary N-donor Ligands

Four novel coordination polymers, [Zn(HL¹)₂(phen)₂]·2CH₃OH·2H₂O (1), [ZnCl(HL¹)(4,4′-bipy)_0.5] _n (2), [Cd(HL¹)(L²)_0.5(2,2′-bipy)₂]·3H₂O (3), [Zn(L³)_0.5(N₃)_1.5(phen)] _n (4) (H₂L¹ = 9-(1H-tetrazole-5-yl)-10-carboxyl anthracene, H₂L² = 9,10-di-(1H-tetrazole-5-yl) anthracene, HL³ = 9-(1H-tetrazole-5-yl)-10-cyan anthracene, 1,10-phen = 1,10-phenanthroline, 4,4′-bipy = 4,4′-bipyridine, 2,2′-bipy = 2,2′-bipyridine), have been constructed by in situ ligands synthesis system. The formation of tetrazole-based ligands H₂L¹, H₂L² and H₂L³ involves the in situ Sharpless [2 + 3] cycloaddition reaction between 9,10-dicyanoanthracene (DCA) and NaN₃ in the presence of Zn²⁺/Cd²⁺ ions as Lewis-acid catalysts under hydro/solvothermal conditions. At the same time, there is also another in situ carboxyl ligand synthesis reaction by hydrolysis from nitrile in compounds 1 and 2. The four compounds have been characterized by elemental analysis, IR and single-crystal X-ray diffraction analysis. Compound 1 exhibits a butterfly-shaped mononuclear structure. Compound 2 represents a 2D framework constructed by six-membered {Zn₆} rings as secondary building units (SBUs). Compound 3 presents a dinuclear {Cd₂} structure with two butterflies “flying side by side” fashion. While compound 4 displays a 1D chain structure based on a dinuclear {Zn₂} SBUs. Moreover, the luminescence properties of 1–4 have been also investigated.     

Synthesis,crystal structures,adsorption and fluorescence properties of coordination polymers based on a semirigid octadentate ligand

Using an octadentate ligand, namely tetrakis[(3,5-dicarboxyphenoxy)methyl] methane (H₈L), four coordination polymers, [Ni₃L(OH)₂(H₂O)₂][NH₂(CH₃)₂]₄·5H₂O (1), [Co₄L(H₂O)₄]·9H₂O (2), [Zn₄L(H₂O)₄]·DMF·11H₂O (3) and [Li₄(H₄L)(H₂O)₄] (4) (DMF = N,N-dimethylformamide), have been solvothermally synthesized and structurally characterized by X-ray crystallography. Complex 1 is an anionic three-dimensional open framework built from tricluster {Ni₃(COOR)₈} and square planar L ligands to give a uninodal 6-connected pcu network. Complexes 2 and 3 are isostructural, possessing a non-interpenetrated three-dimensional network with rare (4,8)-connected scu topology. Complex 4 consists of 4-connecting {Li₂(COOR)₄} clusters which form a 2D Shubnikov tetragonal plane net with sql topology. Complexes 1–3 all have large solvent accessible voids, but only complex 3 possesses permanent porosity as confirmed by N₂, H₂, CO₂ and CH₄ gas adsorption measurements. In addition, complex 3 shows strong photoluminescent emissions at room temperature with a peak at 365 nm, owing to a ligand-centered excited state. The emission intensities of 3 varied upon contact with different solvents or analytes.     

Diverse topologies of three cobalt(II) coordination polymers constructed from flexible bis(benzimidazole) and dicarboxylate ligands

Three cobalt(II) coordination polymers {[Co(L1)(nda)(H₂O)₂]·2H₂O} _n (1), [Co(L2)(tbi)(H₂O)] _n (2) and [Co(L2)(bpdc)(H₂O)] _n (3) (L1 = 1,3-bis(5,6-dimethylbenzimidazol-1-yl)-2-propanol, L2 = 1,3-bis(benzimidazol-1-yl)-2-propanol, H₂nda = 2,6-naphthalenedicarboxylic acid, H₂tbi = 5-tert-butyl isophthalic acid and H₂bpdc = 4,4′-biphenyldicarboxylic acid) were synthesized and characterized by physicochemical and spectroscopic methods. Complex 1 exhibits a 1D loop-like structure, which is further extended into a 3D 3,3,4T31 network through two O–H···O hydrogen bonding interactions. Complex 2 displays a 1D ladder-like chain, arranged into a 2D supramolecular network with 3,3,4L34 topology via classical O–H···O hydrogen bonding interactions, whereas complex 3 features a 2D 3,4L13 layer structure and further assembles into a 3D framework with a twofold interpenetrating sqc65 topology through O–H···O hydrogen bonding interactions. The fluorescence and catalytic properties of these complexes for the degradation of Congo red in a Fenton-like process have been investigated.     

Synthesis,crystal structures,and luminescent properties of three cluster-based heterometallic and monometallic compounds

Two heterometallic cluster compounds and one monometallic cluster compound, namely [Ni₉Co₆(PMIDA)₆(BTC)₂(H₂O)₁₂]·6H₂O (1), [Co₁₃Zn₂(PMIDA)₆(H₂O)₁₈]·6NO₃·15H₂O (2), and [Fe₁₅(PMIDA)₆(BTC)₂(H₂O)₂₂]·38H₂O (3), have been obtained under hydrothermal conditions using N-(phosphonomethyl)imino-diacetic acid (H₄PMIDA) and 1,3,5-benzenetricarboxylate acid (H₃BTC) as ligands, and structurally characterized by X-ray crystallography. Compound 1 exhibits a 3D open framework constructed from [Ni₉Co₆(PMIDA)₆(H₂O)₁₂]⁶⁺ heteronuclear clusters and BTC^3? ligands. Compounds 2 and 3 are both zero-dimensional polynuclear clusters, further extended into 3D supramolecular structures via hydrogen-bonding interactions. However, there are some differences in their crystal structures; compound 2 features an isolated spherical heteronuclear cation cluster based on PMIDA^4? ligands, such that the NO₃ ^? anions only balance the charge, whereas compound 3 is characterized as a neutral monometallic cluster incorporating two different types of organic acid ligands, namely PMIDA^4? and BTC^3?, and the two BTC^3? ligands exhibit regular distribution in each cluster. The luminescence properties of all three compounds have been investigated at room temperature.     

A Disc-Like Heptanuclear Nickel Cluster Based on Schiff Base: Synthesis,Structure, Magnetic Properties and Hirshfeld Surface Analysis

A new disc-like heptanuclear cluster [Ni₇(immep)₆(MeO)₆]·(NO₃)₂ (1, Himmep is 2-imminomethyl-6-ethxoy-phenol) was synthesized through microwave assisted reaction of Ni(NO₃)₂·6H₂O with 2-hydroxy-3-ethoxy-benzaldehyde and ammonium water in mixed solvent (acetonitrile:methanol = 1:1). 1 was characterized by IR spectroscopy, elemental analysis and X-ray single-crystal diffraction. Magnetic property of 1 was discussed. The core of 1 displays dominant ferromagnetic interactions from the nature of the binding modes through μ ₃-OCH₃. According to the 3D Hirshfeld surface and 2D fingerprint plots, the main interactions in 1 are the H···H, O···H, and C···H contacts.     

Synthesis,characterization, and crystal structures of 2D cobalt(II) and nickel(II) coordination polymers containing flexible bis(benzimidazole) ligands

Three coordination polymers, namely {[Ni(L1)(nip)(H₂O)]·2H₂O} _n (1), [Co(L2)(tbip)] _n (2), and {[Co₂(L3)₂(bptc)]·3H₂O} _n (3) (L1 = 1,4-bis(5,6-dimethylbenzimidazole)butane, L2 = 1,4-bis(5,6-dimethylbenzimidazole)-2-butylene, L3 = 1,3-bis(5,6-dimethylbenzimidazole)propane, H₂nip = 5-nitro-isophthalic acid, H₂tbip = 5-tert-butyl-isophthalic acid, H₄bptc = biphenyl-3,3′,4,4′-tetracarboxylic acid), have been synthesized under hydrothermal conditions and characterized by physicochemical and spectroscopic methods as well as by single-crystal X-ray diffraction analysis. Complexes 1 and 2 both feature a two-dimensional (4,4) layer with (4⁴ × 6²) topology. Complex 3 possesses a uninodal 4-connected 2D htb network. The fluorescence spectra and catalytic properties of the complexes for the degradation of methyl orange by sodium persulfate in a Fenton-like process are reported.     

Synthesis,spectral and thermal studies on dicarboxylate-bridged palladium(II) coordination polymers. Part II

The synthesis and thermal behavior of the new [Pd(fum)(bipy)] _n ·2nH₂O (1), [Pd(fum)(bpe)] _n ·nH₂O (2) and [Pd(fum)(pz)] _n ·3nH₂O (3) {bipy = 4,4′-bipyridine, bpe = 1,2-bis(4-pyridyl)ethene and pz = pyrazine} fumarate complexes are described in this work as well their characterization by IR and ¹³C CPMAS NMR spectroscopies. TG curves showed that the compounds released organic ligands and lattice water molecules in the temperature range of 46–491 °C. In all the cases, metallic palladium was identified as the final residue.     

Synthesis,crystal structures,and antibacterial studies of silver(I) complexes with reduced Schiff base amino acid ligands

Three Ag(I) complexes of reduced Schiff base amino acid ligands, [Ag₂(Hshis)₂]·3H₂O (1), Ag(Hcgly) (2), and Ag(cala) (3) (H₂shis = N-(2-hydroxybenzyl)-l-histidine, H₂cgly = N-(2-hydroxy-5-chlorobenzyl)-glycine, Hcala = N-(4-chlorobenzyl)-d,l-alanine), have been synthesized and characterized by X-ray crystallography. Complex 1 shows a dimeric structure, while complex 2 shows one-dimensional zigzag chains, which are extended into a two-dimensional supramolecular sheet by hydrogen bonds. Complex 3 exhibits a 2D sheet structure with dangling arms. The antimicrobial activities of the complexes have been investigated.     

Silver-based coordination complexes of carboxylate ligands: crystal structures,luminescence and photocatalytic properties

The complexes [Ag₄(dpe)₄]·(btec) (1) and [Ag₄(bpy)₄]·(btec)·12H₂O (2) (dpe = 1,2-di(4-pyridyl)ethylene, bpy = 4,4′-bipyridine, H₄btec = 1,2,4,5-benzenetetracarboxylic acid) have been synthesized in aqueous alcohol/ammonia by slow evaporation at room temperature and characterized by elemental analysis, single-crystal X-ray diffraction, FTIR, UV–Vis and luminescence spectroscopies. Both complexes are composed of 1D infinite cationic [Ag/dpe(bpy)] _n ⁿ⁺ chains and discrete btec^4? anions. Their three-dimensional supramolecular structures are built up of cationic sheets formed from [Ag/dpe(bpy)] _n ⁿ⁺ units via weak Ag…Ag and Ag…N interactions, plus anionic btec^4? sheets featuring electrostatic, π–π and hydrogen bonding interactions. Both complexes exhibited photocatalytic activity for the decomposition of methyl orange under UV light irradiation.     

Synthesis,crystal structures,luminescence, and photocatalytic properties of two 1D Co(II) coordination polymers constructed with semirigid bis(benzimidazole) and dicarboxylate ligands

Two ternary cobalt(II) coordination polymers (CPs), namely [Co(L1)(npht)] _n (1) and {[Co₂(L2)₂(npht)₂(H₂O)]·H₂O} _n (2) (L1 = 4,4′-bis(benzimidazol-1-ylmethyl)biphenyl, L2 = 1,2-bis(5,6-dimethylbenzimidazol-1-ylmethyl)benzene, and H₂npht = 4-nitrophthalic acid) have been synthesized and structurally characterized by X-ray crystallography. Both CPs feature similar 1D infinite chains containing two distinct loops. CP 1 further forms a 3D supramolecular network via weak C–H···O hydrogen bond interactions. CP 2 shows a 1D two-layer chain structure, assembled through π–π stacking interactions. The electrochemical, luminescence, and photocatalytic activities of the two CPs for the removal of methylene blue under visible or UV light were investigated. Possible photocatalytic mechanisms are discussed.     

Two manganese(II) coordination polymers containing semirigid bis(benzimidazole) ligands: synthesis,crystal structures,and catalytic properties

Two ternary mixed Mn(II) coordination polymers (CPs), namely [Mn(L1)(Hnip)₂] _n (1) and [Mn(H_0.5L2)₂(H_1.5btc)₂] _n (2) (H₂nip = 5-nitroisophthalic acid, L1 = 1, 4-bis(5,6-dimethylbenzimidazol-1-ylmethyl)benzene, H₃btc = 1,3,5-benzenetricarboxylic acid, L2 = 4,4′-bis(benzimidazol-1-ylmethyl)biphenyl), have been synthesized under hydrothermal conditions and structurally characterized. CP 1 exhibits a non-interpenetrated six-connected pcu framework with the point symbol {4¹²·6³}, while CP 2 features a metal-carboxylate loop-like chain, which is further assembled into a 3D supramolecular network via hydrogen bonds and π–π interactions. The thermal stabilities, luminescence, and catalytic properties of both CPs for the degradation of methyl orange in a Fenton-like reaction have also been investigated.