NDC Ligands Research Articles

Co (II) Boron Imidazolate Framework with Rigid Auxiliary Linkers for Stable Electrocatalytic Oxygen Evolution Reaction.

Metal–organic frameworks (MOFs) have significant potential for practical application in catalysis. However, many MOFs are shown to be sensitive to aqueous solution. This severely limits application of MOFs in electrocatalytic operations for energy production and storage. Here, a Co (II) boron imidazolate framework CoB(im)4(ndc)0.5 (BIF‐91, im = imidazolate, ndc = 2,6‐naphthalenedicarboxylate) that is rationally designed and successfully tested for electrocatalytic application in strong alkaline (pH ≈ 14) solution is reported. In such a BIF system, the inherent carboxylate species segment large channel spaces into multiple domains in which each single channel is filled with ndc ligands through the effect of zeolite channel confinement. These ligands, with strong C—H···π interaction, act as a rigid auxiliary linker to significantly enhance the structural stability of the BIF‐91 framework. Additionally, the π‐conjugated effect in BIF‐91 stabilizes dopant Fe (III) at the atomic scale to construct Fe‐immobilized BIF‐91 (Fe@BIF‐91). Due to the synergistic effect between Fe (III) guest and Co (II) in the framework, the Fe@BIF‐91 acts as an active and stable electrocatalyst for the oxygen evolution reaction in alkaline solution.

Synthesis, Structure, and Properties of New Mg(II)-Metal–Organic Framework and Its Prowess as Catalyst in the Production of 4H-Pyrans

A new alkaline metal–organic framework, [Mg3(NDC)3(DMF)4]·H2O (1) is synthesized solvothermally by using 2,6-naphthalenedicarboxylic acid (NDC) as ligand and dimethylformamide (DMF) and water as mixed solvent. Single crystal X-ray studies show that 1 crystallizes in the space group C2/c with parameters a = 13.4191(2), b = 18.0669(2), c = 20.9746(3) A, and β = 99.66(0)o. The central metal atom Mg(II) adopts a six coordinated octahedral geometry with carboxylate oxygen atoms and DMF molecules. Due to the involvement of oxygen atoms in bridging and chelation binding, a trinuclear secondary building unit is built up, which further connects to other six NDC ligands and finally leading to a three-dimensional network. The thermal and luminescent analysis revealed that the compound is thermally stable with violet emission. The creation of coordinatively unsaturated Mg(II) centers, acting as Lewis-acidic sites upon activation, are explored to use 1 as heterogeneous catalyst in value-added organic conversions. MOF ...

Structure of a new three-dimensional metal-organic framework: Poly[manganese(II)-bis-(µ4-1,4-naphthalenedicarboxylate)-bis-(N,N-dimethylformamide)

A novel metal-organic framework, [Mn2(C12H6O4)2(C3H7NO)2]n has been synthesized solvothermally by assembling ligands 1,4-naphthalenedicarboxylic acid (NDC), N,N-dimethylformamide (DMF) and manganese(II). Both independent Mn(II) ions are six-coordinated in a distorted octahedral environment with oxygen donors. Bis(bridging bidentate) μ4-η1:η1:η2:η1, NDC ligands orient in two directions, [010] and [001], linking the Mn(II) ions to form a square grid in (100) plane. Corner shared Mn(II) octahedral form chains along a direction resulting in a three dimensional network.

Three ZnII Coordination Polymers Based on 1,2-Naphthalenedicarboxylate and Different 4,4′-Bipyridyl-like Bridging Co-ligands: Structural Regulation and Properties

Three new ZnII coordination polymers, namely [Zn(ndc)]n (1), {[Zn(ndc)(bpe)]·1.25H2O}n (2), and {[Zn(ndc)(bpee)]·1.25H2O}n (3), were prepared based on in situ reaction of 1,2-naphthalenedicarboxylic anhydride (ndca) with two different 4,4′-bipyridyl-like bridging co-ligands, bpe and bpee (ndc = 1,2-naphthalenedicarboxylate, bpe = 1,2-bis(4-pyridyl)ethane, and bpee = trans-1,2-bis(4-pyridyl)ethylene). In 1, the ZnII and ndc ligands are directly involved in the polymeric frameworks, forming a 2D (43.63) layered network. Complexes 2 and 3 similarly consist of Zn2(ndc)2 binuclear units that are linked by bpe and bpee ligands, respectively, into a 2D (44.62) sheet. However, further analysis indicates that 2 and 3 feature the similar 2-fold interpenetrating structure linked via hydrogen bonding interactions for 2 and aromatic stacking interactions for 3. In addition, the resultant 2D→3D supramolecular frameworks of 2 and 3 are both constructed via aromatic stacking interactions. Also, the fluorescent and thermal properties of the complexes were investigated.

Temperature-dependent urothermal synthesis of two distinct La(III)-naphthalenedicarboxylate frameworks

Abstract Two distinct La(III)-naphthalenedicarboxylate frameworks, namely La2(NDC)3(e-urea)3 (1; H2NDC = 2,6-naphthalenedicarboxylic acid; e-urea = ethyleneurea) and La(NDC)1.5(e-urea) (2), have been successfully synthesized through urothermal synthesis under different temperatures. Single-crystal X-ray structural analysis revealed that both compounds 1 and 2 feature three-dimensional (3D) structures with open channels occupied by the coordinated e-urea molecules. Interestingly, e-urea molecules and NDC ligands adopt distinct coordination modes in two structures. Furthermore, thermal analyses of 1 and 2 were also investigated.

Syntheses, Structures, and Luminescent Properties of Two Novel Coordination Polymers with Mixed Ligands

Two novel metal–organic coordination polymers {[Pb2(MIP)2(BDC)2]·H2O} n 1 and [Cd(MIP)(NDC)] n 2 [MIP = 2-(3-methoxyphenyl)-1H-imidazo [4,5-f] [1, 10] phenanthroline, BDC = terephthalic acid, NDC = naphthalene-1,4-dicarboxylic acid] were obtained from hydrothermal reaction and characterized by elemental analysis, thermogravimetric (TG) analysis, infrared spectrum (IR) and single-crystal X-ray diffraction. The coordination polymers crystallize in triclinic, space group P-1 with a = 1.0335(2), b = 1.4224(3), c = 1.8156(4) nm, β = 106.088(3)° for complex 1 and the complex 2 crystallizes in monoclinic, space group P2(1)/n with a = 1.2562(8), b = 1.4800(9), c = 1.3723(8) nm, β = 97.257(1)°, respectively. The metal ions Pb(II) are located in [:PbN2O4] pentagonal bipyramidal geometry in complex 1. The metal ions Cd(II) in complex 2 act as distorted octahedral geometry, being surrounded by four carboxylate oxygen atoms from three NDC ligands and two donor nitrogen atoms from one MIP molecule. Moreover, there are hydrogen bonds in the two complexes, and it is noteworthy that the existence of hydrogen bonds and π–π interactions reinforce the structural stability of the title complexes, which have been proved by TG analysis. The luminescent properties for the ligand MIP, NDC and complex 2 are also discussed in detail.

A polythreaded three-dimensional architecture of undulated layers originated by the contribution of different supramolecular interactions

Abstract The structure of compound [Cd2(NDC)2(L)2(H2O)]·0.5DMF (1) (NDC = 1,4-naphthalenedicarboxylate, L = pyrazino[2,3-f][1,10]phenanthroline and DMF = N,N′-dimethylformamide) is reported. Two independent Cd(II) atoms in a distorted [CdO4N2] octahedral environment and three unique NDC ligands showing different coordination modes give strongly undulated two-dimensional grid motifs. Dangling L ligands are chelated to every Cd(II) atom decorating both sides of the layers. Due to the marked undulation of the layers, the large open windows are threaded by the dangling ligands of other layers producing a three-dimensional polythreaded supramolecular array that can be also described as a single three-dimensional framework if the extended columnar face-to-face π–π interactions are considered.

Catena-Poly[[aqua(2,2′-bipyridyl)cobalt(II)]-μ-5-nitroisophthalato

In the crystal structure of the title compound, [Co(C8H3NO6)(C10H8N2)(H2O)]n, there are two symmetry-independent one-dimensional coordination polymers, which are approximately related by noncrystallographic inversion symmetry. Each zigzag chain is constructed from one CoII ion, one O-monodentate 5-nitro­isophthalate (ndc) dianion, one N,N′-bidentate 2,2′-bipyridyl ligand and one water mol­ecule. A symmetry-generated O,O′-bidentate ndc dianion completes the cobalt coordination environment, which could be described as very distorted cis-CoN2O4 octa­hedral. The bridging ndc ligands result in parallel chains running along the a direction, and O—H⋯O hydrogen bonds arising from the water mol­ecules complete the structure.

Hydrothermal Crystallization of Three Calcium-Based Hybrid Solids with 2,6-Naphthalene- or 4,4′-Biphenyl-Dicarboxylates

Three new hybrid solids 1, 2, and 3 of calcium dicarboxylates have been obtained using hydrothermal conditions (24 h, 180 °C) with 2,6-naphathalenedicarboxylic acid (H2ndc) and 4,4′-biphenyldicarboxylic acid (H2bpdc) ligands. According to their single-crystal X-ray diffraction analyses, the three compounds exhibit dense networks with distinct dimensionalities for both the inorganic subnetwork and the whole structure. Three-dimensional (3D) 1 (Ca2(OH)2[ndc]) is built from layers of calcium oxo-hydroxide, pillared via the ndc ligands. Calcium is 7-fold coordinated with a monocapped trigonal prismatic surrounding (CaO4(OH)3). In 2 (Ca(H2O)[bpdc]), the structure consists of infinite chains of calcium polyhedra in a pentagonal bipyramidal coordination (CaO6(H2O) unit), the biphenyldicarboxylate species acting as scaffolds for the 3D structure. Complex 3 (Ca(H2O)3[bpdc]) also contains infinite chains of calcium polyhedra (with 8-fold coordination - CaO4(H2O)4 unit) but this time isolated because one of the two carboxylate functions of the ligand is terminal. The structure is therefore one-dimensional. A network of hydrogen bonds ensures the stability of this structure. Crystal data for 1: monoclinic, P21/c, a = 12.627(2), b = 7.8053(13), c = 5.8555(10) Å, β = 95.954(3)°, and V = 573.97(17) Å3; for 2: monoclinic, P21, a = 5.8237(4), b = 6.9339(5), c = 14.7231(11) Å, β = 93.588(3)°, and V = 593.37(7) Å3; for 3: orthorhombic, Ima2, a = 6.5444(3), b = 30.2468(13), c = 7.2194(3) Å, and V = 1429.06(11) Å3.

Structures, Photoluminescence, Up-Conversion, and Magnetism of 2D and 3D Rare-Earth Coordination Polymers with Multicarboxylate Linkages

Four new rare-earth compounds, [Eu(NDC)1.5(DMF)2] (1), [Nd2(NDC)3(DMF)4].H2O (2), [La2(NDC)3(DMF)4].0.5H2O (3), and [Eu(BTC)(H2O)] (4), where NDC = 1,4-naphthalenedicarboxylate, BTC = 1,3,5-benzenetricarboxylate, and DMF = N,N-dimethylformamide, have been synthesized through preheating and cooling-down crystallization. Compounds 1-3 possess similar 2D structures, in which the NDC ligands link M(III) (M = La, Nd, and Eu) ions of two adjacent double chains constructed by NDC ligands and dinuclear M(III) building units. In compound 4, the Eu(III) ion is seven-coordinated by O atoms from six BTC ligands and one terminal water molecule in a distorted pentagonal-bipyramidal coordination environment. If the BTC ligand and the Eu(III) ion are regarded as six-connected nodes, respectively, the structure of compound 4 can be well described as a 3D six-connected net. Furthermore, compounds 1 and 4 exhibit strong red luminescence upon 355-nm excitation. Compound 2 displays interesting emissions in the near-IR region, and yellow (580 nm) pumping of this compound results in UV and intense blue emissions through an up-conversion process. The magnetic properties of compounds 1, 2, and 4 have been studied through measurement of their magnetic susceptibilities over the temperature range of 4-300 K.

Hydrothermal Syntheses, Structures, and Properties of Three 3‐D Lanthanide Coordination Polymers that Form 1‐D Channels

AbstractWe report the hydrothermal synthesis and crystal structure of isostructural lanthanide coordination polymers [Ln2(NDC)3(phen)2]·H2NDC [Ln = Tb (1), Ho (2) and Yb (3)] that feature 2,6‐naphthalenedicarboxylate (NDC) and 1,10‐phenanthroline (phen) ligands. The NDC ligands bridge the lanthanide ions in two different modes to form a 3‐D porous framework that accommodates large, neutral 2,6‐naphthalenedicarboxylic acid molecules as guests in the channels, stabilized through O−H···O hydrogen bonds to the NDC ligand. The effective dimension of the channel is ca. 6.0 × 8.2 Å. Thermogravimetric analysis shows that complex 2 remains stable up to 330 °C, which we confirmed also by powder X‐ray diffraction analyses. The framework collapsed upon the loss of the coordinating phen molecules. The Tb complex shows strong evidence of ferromagnetic coupling interactions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Novel coordination polymers based on nickel(II) and 2,6-naphthalenedicarboxylate

The two coordination polymers [Ni(ndc)(lutidine) 2(H 2O) 2], CPO-3, and [Ni 3(ndc) 3(pyridine) 4], CPO-4, were obtained by hydrothermal reactions between 2,6-naphthalenedicarboxylic acid (ndc), 3,4-lutidine and nickel(II) nitrate (CPO-3) and ndc, pyridine and nickel(II) nitrate (CPO-4), respectively. In CPO-3, the combination of octahedral nickel(II) ions and ndc ligands leads to the formation of infinite chains. CPO-4 is based on linear trinuclear building units of octahedral nickel(II) ions that are crosslinked via the ndc ligands to form a 3D-structure. The crystal structure of CPO-3 was solved from synchrotron powder X-ray data, while the crystal structure of CPO-4 was solved from conventional single-crystal X-ray data. Crystal data for CPO-3: monoclinic space group Cc (No. 9), a=14.8583(2), b=20.3985(3), c=10.7258(1) Å, β=129.0067(6)°, V=2526.14(5) Å 3 and Z=4. Crystal data for CPO-4: monoclinic space group P2 1/ c (No. 14), a=11.491(3), b=17.917(4), c=12.781(3) Å, β=116.142(7)°, V=2362.2(9) Å 3 and Z=2. The thermal and magnetic properties of both compounds were investigated.

Syntheses, structures, and luminescence properties of a new family of three-dimensional open-framework lanthanide coordination polymers

Deprotonation of 2,6-naphthalenedicarboxylic acid (H 2NDC) with pyridine followed by its copolymerization with Ln(III) nitrates (where Ln = Eu, Tb, Ce) in DMF at room temperature gave a family of 3-D open-framework lanthanide coordination polymers, formulated as {[Ln 2(NDC) 3(DMF) 4]· mH 2O} n (where Ln = Eu, Tb, Ce, 1– 3; m=3, 4, 2 for 1– 3, respectively, DMF = N, N ′-dimethylformamide, and H 2NDC = 2,6-naphthalenedicarboxylic acid) on the basis of elemental analysis and single-crystal X-ray diffraction. Compounds 1– 3 were isostructural and crystallized in triclinic space group P(-1). In these structures, lanthanide ion dimers were interlinked together by NDC ligands with three different carboxylate coordination modes, to yield scaffolds with 3-D interconnecting tunnels where enclathrated water molecules reside. The results of IR and TG were consistent with the structural determination results. Fluorescence measurements show that 1 and 2 emit strong red and green light, respectively, upon irradiation with UV–vis light source. However, these open frameworks collapsed upon desolvation as evidenced by XRPD investigations, which renders their potential use as fluorescent sensors impossible.