Three New Cadmium Complexes Based on 3-Nitrophthalic Acid: Syntheses,Crystal Structures and Fluorescent Properties

Three metal–organic coordinate complexes based on 3-nitrophthalic acid (H₂NPA), namely Cd₂(H₂O)(OH)₂(NPA) (1), Cd₂(Im)₄(NPA)₂ (2) and Cd₂(Bim)₄(H₂O)(NPA)₂ (3) (Im = imidazole, Bim = benzimidazole), have been obtained by hydrothermal method and characterized by X-ray single crystal structure determination. Structural analysis reveals that complex 1 exhibits 2D layers constructed by polyhedral aggregates. Complex 2 exhibits a dinuclear cadmium structural unit and assembles by hydrogen bonds into a 2D supramolecular architecture. Complex 3 is assembled by NPA^2? into layers of a (3,4)-connected dinodal net topology of (4·5₂)(4·5₃·7₂). The fluorescent properties of complexes 1–3 have been investigated.     

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.     

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.     

Co(II) and Ni(II) complexes with imidazole-containing ligands: Synthesis,structural characterization,and magnetic property

Hydrothermal reaction of Co(II) salt with 1,4-di(1-imidazolyl)benzene (L¹) and 4,4’-oxydiphthalic acid (H₄OA) yields a new complex [Co₃(HOA)₂(L¹)₄(H₂O)₄] (I). [Ni(L²)₂SO₄] · 0.5H₂O (II) can be obtained via the hydrothermal reaction of NiSO₄ · 6H₂O with 1,3-di(1H-imidazol-4-yl)benzene (L²). Complexes I and II have been characterized by single-crystal and powder X-ray diffraction (CIF files CCDC nos. 1019291 (I) and 1019292 (II)), IR, elemental, and thermogravimetric analyses. Complex I exhibits the uninodal six-connected 3D pcu framework structure of I with (4¹² · 6³) topology; Complex II consists of the uninodal four-connected 2D sql (4⁴ · 6²) networks. In addition, magnetic property of I was investigated.     

Synthesis,crystal structures,and properties of copper(II) dicarboxylate complexes with [bis(2-pyridylcarbonyl)amido]

Four new complexes, [Cu₂(Bpca)₂(L¹)(H₂O)₂] · 3H₂O (I), [Cu₂(Bpca)₂(L²)(H₂O)₂] (II), [Cu₂(Bpca)₂(L³)] · 2H₂O (III), [Cu₂(Bpca)₂(L¹)(H₂O)] · 2H₂O (IV) (Bpca = bis(2-pyridylcarbonyl)amido, H₂L¹ = glutaric acid, H₂L² = adipic acid, H₂L³ = suberic acid, H₂L⁴ = azelaic acid) have been synthesized and characterized by single-crystal X-ray diffraction methods (CIF files CCDC nos. 1432836 (I), 1432835 (II), 817411 (III), and 817412 (IV)), elemental analyses, IR spectra. Structural analyses reveal that compounds I, II, and IV have similar structures [Cu(Bpca)]⁺ units bridged by dicarboxylate forming dinuclear units, whereas the dinuclear of compound III are edge-shared through two carboxylate oxygen atoms of different suberate anions. Hydrogen bonds are response for the supramolecular assembly of compounds I to IV. The temperature-dependent magnetic property of III was also investigated in the temperature range of 2 to 300 K, and the magnetic behaviour suggests weak antiferromagnetic coupling exchange.     

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.     

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.     

2,6-diformyl-4-<Emphasis Type="Italic">tert</Emphasis>-butylphenol bis-ferrocenoylhydrazone and binuclear copper(II) complexes on its basis

2,6-Diformyl-4-tert-butylphenol bis-ferrocenoylhydrazone (1, H₃L) and binuclear copper(II) complexes on its basis [Cu₂(H₂L)(OH)] (2), [Cu₂(H₂L)Cl₃]·(3), and [Cu₂(H₂L)(OH)]·₂NO₃ (4) have been synthesized and investigated. Tautomerism of bis-hydrazone (1) has been studied.     

Coordination assemblies of rigid–flexible 1,3-bis(5-(pyridine-2-yl)-1,2,4-triazole-3-yl)propane ligands with MCl<Subscript>2</Subscript> (M = Fe,Co, Cu or Zn): structural diversity and mass spectra

Reactions of the rigid–flexible N-heterocycle 1,3-bis(5-(pyridine-2-yl)-1,2,4-triazole-3-yl) propane (H₂L) with MCl₂ (M = Fe, Co, Cu or Zn) gave coordination complexes, {[Fe ₂ ^III Cl₄(H₂L)₂]·2Cl}·EtOH·H₂O (1), {[Co₃Cl₅(HL)]·H₂O} _n (2), {[Co₄Cl₄(H₂L)₂(H₂O)₄]·[CoCl₄]₂}·H₂O (3), [Cu₂Cl₃(HL)(H₂O)]₆·5H₂O (4), [Cu ₂ ^II Cu^ICl₄(HL)] _n (5), {[Zn₂Cl₂(L)H₂O]·H₂O} _n (6) and [Zn₄Cl₆(HL)₂] (7), which have been characterized by single-crystal X-ray diffraction. Structural analysis reveals that the pyridine triazole ligand attains versatile coordination modes in these complexes. Complexes 1, 3, 4 and 7 consist of 0D clusters with binuclear or tetranuclear units; complex 2 presents a 2D network accompanied by HL^? and chloride bridges; complexes 5 and 6 show 1D chains with [Cu₃] and [Zn₂] subunits. In addition, the electrospray ionization mass spectrometry properties of selected complexes were investigated, revealing the stabilities and structural states of these complexes in solution. These results indicate that H₂L is an excellent multiconnection linker for the construction of diverse coordination complexes.     

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.     

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.     

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.     

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.     

A dual-functional cadmium(II) coordination polymer as a luminescent sensor for selective sensing of iron(III) ions and detecting the temperature

A Cd(II) coordination polymer (1), {[Cd₂(Ccbp)₂(dca)Cl·3H₂O]·4H₂O} Ccbp^? = 4-carboxy-1-(3-carboxybenzyl)pyridin-1-ium and dca^? = dicyanamide, has been synthesized via a hydrothermal reaction and fully characterized by single-crystal X-ray structural analysis, FTIR spectroscopy, powder X-ray diffraction, and thermogravimetric analysis. Complex 1 has a 2D network structure with uncoordinated functional groups. Its solid-state luminescence properties were measured at room temperature. Complex 1 exhibited a high sensitivity for Fe³⁺ in DMF solutions of mixed metal ions. In addition, the temperature-dependent luminescence properties of 1 have been investigated and show that the complex acts as a luminescent thermometer over a temperature range from 10 to 90 K.     

Two novel coordination polymers: Synthesis,structure, luminescent properties,and selective sensing of Cu<Superscript>2+</Superscript> and Mn<Superscript>2+</Superscript> ions

Two novel coordination polymers, namely {[Co(Ttac)_0.5(1,4-Bib)(H₂O)] · H₂O}_n (I) and {[La(HTtac)₂(2H₂O)] · H₂O}n (II) (H4Ttac = 4,5-di(3'-carboxylphenyl)-phthalic acid, 1,4-Bib = 1,4-bis(1-imidazoly) benzene), have been designed and successfully prepared via hydrothermal process, and characterized by elemental analyses, IR spectroscopy, and single crystal X-ray diffraction (CIF files CCDC nos. 1039298 (I), 1039300 (II)). Structural analysis reveals that the H₄Ttac ligands adopt different coordination modes in the as-synthesized I and II, and thus give rise to the targeted coordination polymers with different configurations. It is worth mentioning that, coordination polymer I is assembled from low-dimensional structures into three-dimensional (3D) via π···π stacking interactions, while three-dimensional coordination polymer II is formed by covalent bonds. Luminescent properties of coordination polymer II have been studied at ambient temperature. Significantly, luminescent measurement indicates that coordination polymer II may be acted as potential luminescent recognition sensors towards Cu²⁺ and Mn²⁺ ions.     

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.     

Antiferromagnetic Coupling in a New Mn(III) Schiff Base Complex with Open-Cubane Core: Structure,Spectroscopic and Luminescence Properties

A new open-cubane Mn^III, [{(H₂O)Mn^IIIL}{Mn^IIIL}]₂·2(CH₃OH).2(CH₃CH₂OH)·2Cl, 1 where H ₂ L=[N-(2-hydroxyethyl)-3-methoxysalicylaldimine] has been synthesized and characterized by element analysis, FT-IR, solid UV–Vis spectroscopy and single crystal X-ray diffraction. The crystal structure determination shows an open-cubane tetranuclear complex. The Mn1 (Mn1ⁱ) ions is hexacoordinate by NO₅ donor sets while the Mn2 (Mn2ⁱ) is pentacoordinate by NO₄ donor sets. The solid state photoluminescence properties of complex 1 and its ligand H ₂ L have been investigated under UV light at 349 nm in the visible region. H ₂ L exhibits blue emission while complex 1 shows orange-red emission at room temperature. Variable-temperature magnetic susceptibility measurements on the complex 1 in the range 2–300 K indicate an antiferromagnetic interaction.     

Synthesis,Structure and Properties of a Novel Tetranuclear Copper Cluster-Based Polymer with Di-Schiff-Base

A novel tetranuclear cluster-based polymer {[Cu₄(L)₂(NO₃)₂(DMF)₂]·(CH₂Cl₂)₂}_n (1, H₃L = (1Z,2E,N′E)-N′,2-bis(2-hydroxybenzylidene)hydrazinecarbohydrazonic acid) was synthesized through diffusion method. The structure of 1 was characterized by elemental analysis, IR, and single crystal X-ray diffraction. 1 is tetranuclear copper cluster which further constructed 1-D chain through double Cu–O bonds. Luminescent and magnetic properties of 1 have been studied. Hirshfeld surfaces analysis revealed that complex 1 was supported mainly by H···H, O···H and H···Cl intermolecular interactions.     

Synthesis,crystal structures,and properties of three coordination polymers of 5-(1H-imidazol-1-yl) isophthalic acid

Three coordination polymers have been obtained by hydrothermal synthesis, namely [Zn(imip)(H₂O)₂]·0.5H₂O (1), [Co(imip)(H₂O)₂]·0.5H₂O (2), and [Cd₂(imip)₂(H₂O)₃] (3) [H₂imip = 5-(1H-imidazol-1-yl) isophthalic acid]. The coordination polymers were characterized by IR spectra, elemental analysis, powder X-ray diffraction, and thermogravimetric analysis. Furthermore, single-crystal X-ray analysis reveals that they have 2D structures, which are extended into 3D networks via O–H···O hydrogen-bonding interactions. The luminescent properties of these coordination polymers were investigated.     

Syntheses and electrochemical properties of three supramolecular architectures based on Keggin silicontungstates and different metal-organic units

Three new compounds [Mn(H₂O)₂(bimb)₂(H₃SiW₁₂O₄₀)₂](bimb)₄ (1), [Zn₂(bimb)₄(H₂O)₄][SiW₁₂O₄₀] (2), and [Ni₂(bimb)₄(H₂O)₄][SiW₁₂O₄₀] (3) (bimb = 1,3-bis(1-imidazoly)benzene) have been synthesized under the same hydrothermal reaction except for tuning the metal cations (Mn²⁺, Zn²⁺, and Ni²⁺). Structural characterizations show that the three compounds possess distinct structural motives. Compound 1 displays a supramolecular one-dimensional (1 D) chain formed by π···π interactions that occur among the almost parallel bimb ligands from adjacent [Mn(H₂O)₂(bimb)₂(SiW₁₂O₄₀)₂] dimers. Compound 2 shows a supramolecular two-dimensional (2D) layer achieved by intermolecular (C–H···O) hydrogen bondings between the Zn₂(bimb)₄ molecular loops and the SiW₁₂ anions. Compound 3 also exhibits a supramolecular 2D layer, but it is different from 2, which is generated by the π···π interactions among adjacent 1D polymeric chains. The distinct structural features of the three compounds suggest that the metal cations should play a significant role in the process of assembly. Additionally, the electrochemical properties of compounds 1–3 have been investigated, and the results indicate that compounds 1–3 possess excellent electrocatalytic activity toward reduction of both iodated and nitrite molecules.