Synthesis and structural characterization of binuclear ytterbium(III) complexes with 2-amino and 3-amino benzoic acid

Two novel homobinuclear ytterbium(III) complexes, [Yb₂(2AMB)₆(H₂O)₄] · 2C₂H₆O (I) and Yb₂(3AMB)₆(H₂O)₄] · 3H₂O (II) (2AMB = 2-aminobenzoic acid, 3AMB = 3-aminobenzoic acid) have been synthesized and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis and X-ray crystallography (CIF files CCDC nos. 950103 (I), 921652 (II)). Complex I crystallizes in triclinic space group \(P\bar 1\) and complex II crystallizes in monoclinic space group P2₁/n. X-ray analysis shows that both complexes (I, II) have the dinuclear structure. The central Yb³⁺ ions in both complexes are eight-coordinated adopting distorted YbO₈ dodecahedral geometry. Each Yb³⁺ ion is coordinated to two O atoms from bridging carboxylate, four O atoms from the chelating carboxylate ligands and two O atoms of water molecules. The crystal structure of I and II are stabilized by N-H…O, O-H…O, O-H…N, and C-H…O hydrogen bonds, C-H…π interactions and weak π-π stacking interactions.     

Syntheses and structures of p-HOOCC6F4COOH · H2O (H2L · H2O) and luminescent coordination polymers [Tb2(H2O)4(L)3 · 2H2O] n and Tb2(Phen)2(L)3 · 2H2O

Compounds p-HOOCC₆F₄COOH · H₂O (H₂L · H₂O), [Tb₂(H₂O)₄(L)₃ · 2H₂O] _n (I), and Tb₂(Phen)₂(L)₃ · 2H₂O (II) are synthesized. According to the X-ray structure analysis data, the crystal structure of H₂L · H₂O is built of centrosymmetric molecules H₂L and molecules of water of crystallization. The crystal structure of compound I is built of layers of coordination 2D polymer [Tb₂(H₂O)₄(L)₃] _n and molecules of water of crystallization. The ligands are the L^2? anions performing both the tetradentate bridging and pentadentate bridging-chelating functions. The coordination polyhedron TbO₉ is a distorted three-capped trigonal prism. Acid H₂L manifests photoluminescence in the UV region (??_max = 368 nm). Compounds I and II have the green luminescence characteristic of the Tb³⁺ ions, and the band with ??_max = 545 nm (transition ⁵ D ₄?? ⁷ F ₅) is maximum in intensity. The photoluminescence intensity of compound II is higher than that for compound I.     

Four Ln(III) coordination polymers based on 1H-benzimidazole-5,6-dicarboxylate ligand: Synthesis, crystal structure, and luminescence

Four Ln(III) coordination polymers, [La₂(HBidc)₃(H₂O)] _n (I), [Pr₂(HBidc)₃(H₂O)] _n (II), [Sm₂(HBidc)₃(H₂O)] _n (III), and [Gd₂(HBidc)₃(H₂O)] _n (IV), were synthesized hydrothermally by treating Ln(NO₃)₃ · 6H₂O, NaOH, and H₃Bidc (H₃Bidc = 1H-benzimidazole-5,6-dicarboxylic acid) at 180°C and characterized by elemental analysis, IR spectra, and single-crystal X-ray structure analyses. Complexes I–IV are isostructural, and each complex contains two crystallographically independent Ln(III), one is seven-coordinated, while the other is eight-coordinated. X-ray crystallography reveals that the complex consists of 3D frameworks with the (3⁴·4⁴·5²·6⁶·7¹⁰·8·9)(3·4·5)(3·4·5) topology. Furthermore, the photoluminescence properties of III has been studied.     

Water-induced reversible dissolution/reorganization transformations of Cu(Ⅱ)-K(I) heterometallic coordination polymers

Three new heterometallic coordination compounds, namely, [KCu(I3)(L)2(H2O)2]n(1), [KCu(I3)(L)2(H2O)]n(2) and [CuK4(I3)2(L′)4]n(3), were prepared and characterized(HL=5-methylpyrazine-2-carboxylic acid, HL′=p-tolylacetic acid). Structural studies revealed that 1 and 2 exhibit 3D frameworks with rectangular channels occupied by triiodide ions. Both compounds can be symbolized as a 5-connected net with pcu topology. In compound 3, a one-dimensional polyhedral chain is connected by hexanuclear mask like clusters [Cu2K4O8]. These chains are further linked each other via rare(1,1,3,3)-triiodide ion-bridging units to generate a 3D(4,5,6)-connected net with the point symbol of {12}2{4·122}4{46}{48·62}4{49·66}4. It is noteworthy that water-induced reversible dissolution/reorganization processes occur between 1/2 and [Cu(L)2(H2O)]n·3nH2O. The thermal and photoluminescence properties of compounds 1, 2, and 3 were investigated as well.     

Hydrothermal synthesis, crystal structures, and properties of two Co(II) complexes based on 4-bromoisophthalic acid and N-donor ligands

Two new Co(II) complexes, [Co₂(H₂O)(Bipy)₂(Bript)₂] _n (I) and [Co(H₂O)(Phen)(Bript)] · H₂O (II), where H₂Bript = 4-bromoisophthalic acid, Bipy = 2,2??-bipyridine, and Phen = 1,10-phenanthroline, have been synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. Complex I has binuclear units in which two Co²⁺ ions are bridged by two carboxylate groups and a coordinaiod-water molecule, and the binuclear units are connected by Bript to generate a 1D helical chain. These 1D helical chains are further linked by ????? stacking interactions to form a 3D supramolecular network, while complex II has a 2D layer motif. In I and II, there exists extensive hydrogen bonding interactions. The thermal behavior of the two corresponding complexes have briefly been investigated.     

Synthesis, structure, and photoluminescence properties of a novel 3D 3d-4f heterometallic polymer: Pr4(H2O)9Cu3.5Cl0.5(Bpdc)6.5(OH)2 · 5H2O (H2Bpdc = 2,2′-bipyridyl-5,5-dicarboxylic acid)

A novel 3D 3d–4f heterometallic polymer Pr₄(H₂O)₉Cu_3.5Cl_0.5(Bpdc)_6.5(OH)₂ · 5H₂O (I) (H₂Bpdc = 2,2′-bipyridyl-5,5′-dicarboxylic acid) has been hydrothermally synthesized by the reaction of CuCl₂ · 2H₂O, PrCl₃, H₂Bpdc, TAA (TAA = 1H-tetrazolyl-1-acetic acid) and glacial acetic acid and characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. Single-crystal structural analysis shows that I displays an interesting heterometallic 3D coordination framework constructed from 2D praseodymium-oxygen layers and [Cu(Bpdc)2]^3? and [CuCl(Bpdc)]^2? pillars. The photofluorescence properties of I have been investigated.     

Two new 2D copper(II) complexes constructed from a flexible bis-pyridyl-bis-amide ligand and two aromatic tricarboxylates: syntheses, crystal structures, fluorescence, and electrochemical properties

Two new 2D metal-organic complexes, namely [Cu(3-dpyb)(1,2,4-HBTC)(H₂O)]·H₂O (1) and [Cu₃(3-dpyb)₃(SIP)₂(H₂O)₈]·6H₂O (2) [3-dpyb?=?N,N??-bis(3-pyridinecarboxamide)-1,4-butane, 1,2,4-H₃BTC?=?1,2,4-benzenetricarboxylic acid, H₃SIP?=?5-sulfoisophthalic acid], have been hydrothermally synthesized and structurally characterized by elemental analyses, IR, TG, and single crystal X-ray diffraction analyses. Single crystal X-ray analyses reveal that the two Cu(II) complexes show different 2D coordination networks, the 4-connected (4⁴·6²) topology for complex 1 and the (4·6²)₂(4²·6²·8²) topology for complex 2. In the 2D layers of complexes 1 and 2, the 3-dpyb ligands adopt a typical ?? ₂-bridging mode (via ligation of two pyridyl nitrogen atoms), while 1,2,4-HBTC and SIP serve as a linear spacer and a ??V??-like linker, respectively, to connect the adjacent Cu(II) centers. The adjacent 2D layers are extended to 3D supramolecular networks via hydrogen-bonding interactions. The fluorescence properties of both complexes and electrochemical properties of complex 2 have also been investigated. The complex 2 bulk-modified carbon paste electrode (2-CPE) displayed a one-electron redox wave in potential range of 600?C200?mV in 1?M H₂SO₄ aqueous solution, and 2-CPE showed good electrocatalytic activity toward the reduction of nitrite.     

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.     

Tansition metal complexes with 2-(1-(carboxymethyl)-2-methyl-1H-benzimidazol-3-ium-3-yl)acetate (HL): Synthesis and crystal structure of [Co(L)2(H2O)4] · 6H2O and [Cu(L)2(H2O)2] · 4H2O

Transition metal complexes of 2-(1-(carboxymethyl)-2-methyl-1H-benzimidazol-3-ium-3-yl)acetate (HL), namely [Co(L)₂(H₂O)₄] · 6H₂O (I) and [Cu(L)₂(H₂O)₂] · 4H₂O (II), have been synthesized by a hydrothermal procedure and characterized by X-ray crystallography, CIF files CCDC nos. 1007524 (I), 1007525 (II). Both I and II are mononuclear molecules. In I, the Co²⁺ ion is in octahedral coordiantion environment and surrounded by four O atoms from water molecules and two carboxylate O atoms of two deprotonated ligand (L^?) occupied six culmination. While in II, the Cu²⁺ ion is located in a square-planar geometry, bounded to two aqua O atoms and two carboxylate O atoms from L^?.     

Synthesis, crystal structure, and porosity calculation of novel lanthanide coordination polymers involving naphthalene-1,4,5,8-tetra-carboxylate as ligand

Two isostructural microporous coordination polymers of 1,4,5,8-naphthalenetetracarboxylic acid (H₄Ntc) with rare earth metals were obtained in gel diffusion method, with chemical formulae [Y₂(Ntc)_1.5(H₂O)₅] · 6H₂O) (I) and [Er₂(Ntc)_1.5(H₂O)₅] · 6H₂O (II). They crystallized in the monoclinic system, space group P2₁/c. The crystal structure study revealed two crystallographically independent La³⁺ ions, and two crystallographically independent ligands were in the structure of the compounds I and II. Their crystal structure were 3D and exhibited some large channels with rectangular sections spreading along the x axis. The porosity has been calculated using Connolly’s algorithm after the crystallization water molecules were formally removed.     

Isomorphous crystal structures of 4,7,13,16,21,24-hexaoxo-1,10-diaziniabicyclo[8.8.8]·hexacosane bis(tribromide) and bis(bromoiodide)

Two compounds, 7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane bis(tribromide) and bis(bromodiiodide) — [H₂(Crypt-222)]²⁺·2Br ₃ ^? (I) and [H₂(Crypt-222)]²⁺·1.45(BrI₂)^?·0.4(Br₂I)^?·0.15 I ₃ ^? (II) — are prepared and characterized by single crystal XRD; the refinement of the second compound was more accurate. Isomorphous monoclinic structures (I, space group C2/c, Z = 4, a = 12.090, b = 15.833 Å, c = 15.732 Å, β = 95.83°; II, a = 12.548 Å, b = 16.417 Å, c = 15.748 Å, β = 94.53°) are solved by a direct method and refined in the anisotropic full-matrix approximation to R = 0.057 (I) and 0.044 (II) using all 2635 (I) and 2852 (II) measured independent reflections (automated CAD-4 diffractometer, λMoK _α). In the structures of I and II one of the trihalide anions sits at the inversion center i(000), and the second trihalide anion and the dication [H₂(Crypt-222)]²⁺ are situated at crystallographic axis 2. In the structure of II iodine is located in the center of trihalide anions, while the terminal atoms are disordered and are represented by a statistical combination of iodine and bromine atoms.     

Coordination polymer with the framework structure [Zn2(DMA)(Atc)] · DMA: Synthesis, structure, and properties

Crystals of a new coordination polymer with the framework structure, [Zn₂(DMA)(Atc)] · DMA (I), were prepared by heating a solution of Zn(NO₃)₂ · 6H₂O and H₄Atc (H₄Atc is 1,3,5,7-adamantanetetracarboxylic acid) in N,N′-dimethylacetamide (DMA). Colorless crystals of Zn₂(Atc) · 2MeOH · 4H₂O (II) were obtained by soaking the crystals of compound I in methanol. The structure of compound I was determined by X-ray diffraction analysis. Compounds I and II were characterized by X-ray powder diffraction, IR spectroscopy, thermal gravimetric analysis, and elemental analysis. The luminescence properties of compound I were studied.     

Solventothermal syntheses, structures and photoluminescence of two-dimensional lanthanide coordination polymers with adipic acid

Four lanthanide coordination polymers formulated as [Ln₂(Ad)₃(H₂O)₄] · 0.25H₂O ( Ln = Tb (I), Pr (II), Ho (III), Dy (IV); H₂Ad = adipic acid), have been solventothermally synthesized from the self-assembly of the lanthanide ions (Ln³⁺) with the exible adipic dicarboxylate ligand. All of them were characterized by IR spectroscopy and single-crystal X-ray diffraction. Structural analyses revealed that these complexes had intricate two-dimensional interpenetrated metal-organic networks. In addition, the photoluminescent properties of complex I was discussed in detail, which shows strong green emission, corresponds to ⁵ D ₄ → ⁷ F ₅ transition of Tb³⁺ ions.     

Construction of 0D to 3D Copper(II) MOFs based on heterocyclic carboxylic acid: Synthesis,structures, cyclic voltammograms,and luminescent properties

The crystal structures of MOFs [Cu(PDA)(Phen)(H₂O)]₂ · 5H₂O (I) and [Cu(PZCA)₂(H₂O)₂] · 2H₂O (II) (H₂PDA = pyridine-2,6-dicarboxylic acid, Phen = 1,10-phenanthroline, HPZCA = pyrazine-2-carboxylic acid, H₂PZDA = pyrazine-2,3-carboxylic acid) have been prepared under hydrothermal conditions. These MOFs have been characterized by element analysis, single-crystal X-ray diffraction, thermogravimetric analyses and IR spectroscopy. 3D frameworks of MOFs I and II are fabricated from zero-dimensional (0D) motifs through hydrogen bonds and π-π interactions. In MOF II, the PZCA ligand comes from in situ decarboxylation of the part of pyrazine-2,3-dicarboxylic acid (H₂PZDA). Luminescent emissions bands of MOF I in methanol have been measured at room temperature and it displays selectivity to Zn²⁺, Cu²⁺, Pb²⁺, and Cd²⁺ ions. Cyclic voltammetry of MOFs I and II showed that the Cu(II/I) couple is irreversible.     

Synthesis, crystal structure, and luminescent property of [Zn2(Ox)3]H2L · 4H2O (L = 2,2′-(1,4-butanediyl-bis(1H-benzimidazole))

A new complex [Zn₂(Ox)₃]H₂L · 4H₂O (L = 2,2??-(1,4-butanediyl)-bis(1H-benzimidazole)) (I) has been hydrothermally synthesized and characterized by the elemental analysis, IR spectroscopy, and single crystal X-ray diffraction. It crystallizes in monoclinic space group P2₁/c with a = 10.108(2), b = 15.600(4), c = 9.768(2) ?, ?? = 105.289(3)·, V = 1485.7(6) ?³, Z = 4. Complex I is a 2D honeycomb-like polymer with pro-toned L and water molecules intercalating in the cavities. The luminescent spectra shows the emission peak of complex I is at 455 nm which is attributed to ligand-to-metal charge transfer.     

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.     

Construction of two metal coordination polymers based on 1,4-terephthalate and 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene

Two new metal-organic frameworks, namely, Cd(BDC)(Btx) · 0.25(H₂O) (I) and Co₃(BDC)₃(Btx)₄(H₂O)₄ (II) (H₂BDC = 1,4-terephthalate acid and Btx = 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene), have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, TGA, and single crystal X-ray diffraction. Complex I exhibits a scarcely reported an eight-connected (4²⁴.6⁴) net with dinuclear cadmium clusters as secondary building units, whereas complex II displays a three-dimensional co-ordination polymer with a rare (4,6)-connected net described by the (4⁴.6²)₂(4⁸.6⁷) Schläfli symbol. In addition, the luminescence measurements reveal that complex I exhibits strong fluorescent emissions in the solid state at room temperature.     

Construction of a new one-dimensional Hg(II) coordination polymer [Hg4(Chbz)4(4,4′-Bipy)2(NO3)4 · H2O] n involving in situ chlorobenzene synthesis

A new 1D Hg(II) coordination polymer, [Hg₄(Chbz)₄(4,4′-Bipy)₂(NO₃)₄ · H₂O] _n (I) (Chbz = 2-chlorophenyl, 4,4′-Bipy = 4,4′-bipyridine), has been synthesized by the in situ synthesis of 2-chlorophenyl from the reaction of 2-chlorobenzoic acid, 4,4′-Bipy and mercury salt under hydrothermal conditions and characterized by elemental analysis, IR, TGA and single-crystal X-ray diffraction. Complex I exhibits an interesting 1D infinite zigzag polymeric chain along the x axis. The photoluminescent measurements reveal that complex I exhibits fluorescent emission in the solid state at room temperature.     

Hydrothermal synthesis, crystal structure of three novel complexes based on thiabendazole and 1,4-benzenedicarboxylate ligands

Three novel metal-organic complexes [Co(BDC)(TBZ)₂] (I), [Cd₂(BDC)₂(TBZ)₂(H₂O)₂] · 2(H₂O) (II), [Mn₂(BDC)(TBZ)₄(SO4)] (III) (BDC = 1,4-benzenedicarboxylate, TBZ = thiabendazole) have been prepared and characterized by IR spectrum, elemental analysis, thermogravimetric analysis, and single-crystal X-ray diffraction. X-ray structure analysis reveals that both three complexes are one-dimensional chain polymers. The 1D chain architecture of I is constructed from terephthalic acid and cobalt atoms. A simultaneous presence of chelating and monodentate coordination modes of BDC ligands is observed in complex II. In complex III, the coordinated BDC ligands adopt monodentate mode and with SO ₄ ^2? anions alternately bridge the Mn²⁺ ions into 1D chains. The 3D structures of the three complexes are stabilized by π-π stacking interactions and hydrogen-bonds.     

A new 2D Mn(II) coordination polymer constructed from carboxylate and N-donor coligand: Synthesis,structure, and magnetism

A new complexes, namely, {[Mn₂(L)₂(Bipy)₂] · H₂O} _n (I) (H₂L = diphenic acid, Bipy = 4,4′-bipyridine) has been synthesized and structurally characterized by single-crystal diffraction analysis. In I, the two syn, anti-carboxylate groups in L bridge Mn(II) forming a one-dimensional chain, which is further connected by Bipy into 2D double layer. Magnetic study reveals the overall antiferromagnetic interaction between neighboring Mn²⁺ ions in compound I.