3d-4f Heterometallic Coordination Polymers Research Articles

A Series Three-Dimensional Ln4Cr4 (Ln = Gd, Tb, Er) Heterometallic Cluster-Based Coordination Polymers Containing Interesting Nanotubes Exhibiting High Magnetic Entropy.

A series of novel 3D 3d-4f heterometallic cluster-based coordination polymers, [Ln4Cr4(μ3-O)4(μ4-O)4(NA)8(H2O)12]·xH2O (Ln = 1-Gd, 2-Tb, 3-Er; HNA = nicotinic acid; x = 13 (1-Gd), 11.33 (2-Tb), 15 (3-Er)), have been successfully synthesized by hydrothermal method using nicotinic acid as bridging ligand. The single-crystal X-ray diffraction (SCXRD) analysis indicated that the basic unit of Ln4Cr4 shows a butterfly-shaped structure. Furthermore, each Ln4Cr4 cluster connects with other four Ln4Cr4 clusters by bridging NA- ligands to form a 3D structure containing interesting 1D honeycomb-shaped coordination nanotubes. The variable temperature magnetic susceptibility measurements of compound 1 revealed that the existence of antiferromagnetic (AF) coupling between the metal ions in the Gd4Cr4 clusters. Field-dependent isothermal magnetization studies displayed that the magnetic entropy change (-ΔSm) value of 1-Gd reached 22.05 J K-1 kg-1.

Toward a Rational Design of 3d-4f Heterometallic Coordination Polymers based on Mixed Valence Copper Centers

In the present work, we report two new CuI/CuII–GdIII mixed valence heterometallic coordination polymers (HCP), [Gd(H2O)4CuIICuI(IDC)2] (1) and [Gd2(H2O)2(C2O4)2CuII(IDC)2CuI2(4,4′-bipy)]·4.5H2O (2...

Synthesis and characterization of two isostructural 3d-4f coordination compounds based on pyridine-2,6-dicarboxylic acid and 4,4'-bipyridine.

The design and synthesis of 3d-4f heterometallic coordination polymers have attracted much interest due to the intriguing diversity of their architectures and topologies. Pyridine-2,6-dicarboxylic acid (H2pydc) has a versatile coordination mode and has been used to construct multinuclear and heterometallic compounds. Two isostructural centrosymmetric 3d-4f coordination compounds constructed from pyridine-2,6-dicarboxylic acid and 4,4'-bipyridine (bpy), namely 4,4'-bipyridine-1,1'-diium diaquabis(μ2-pyridine-2,6-dicarboxylato)tetrakis(pyridine-2,6-dicarboxylato)bis[4-(pyridin-4-yl)pyridinium]cobalt(II)dieuropium(III) octahydrate, (C10H10N2)[CoEu2(C10H9N2)2(C7H3NO4)6(H2O)2]·8H2O, (I), and 4,4'-bipyridine-1,1'-diium diaquabis(μ2-pyridine-2,6-dicarboxylato)tetrakis(pyridine-2,6-dicarboxylato)bis[4-(pyridin-4-yl)pyridinium]cobalt(II)diterbium(III) octahydrate, (C10H10N2)[CoTb2(C10H9N2)2(C7H3NO4)6(H2O)2]·8H2O, (II), were synthesized under hydrothermal conditions and characterized by IR and fluorescence spectroscopy, thermogravimetric analysis and powder X-ray diffraction. Both compounds crystallize in the triclinic space group P-1. The EuIII and TbIII cations adopt nine-coordinated distorted tricapped trigonal-prismatic geometries bridged by three pydc2- ligands. The CoII cation has a six-coordination environment formed by two pydc2- ligands, two bpy ligands and two coordinated water molecules. Adjacent molecules are connected by π-π stacking interactions to form a one-dimensional chain, which is further extended into a three-dimensional supramolecular network by multipoint hydrogen bonds.

Synthesis, Crystal Structures and Magnetic Properties of Carboxyl Bridged 3d–4f Heterometallic Coordination Polymers Based on Metalloligand and Lanthanide Ions

Two new three-dimensional 3d–4f heterometallic coordination polymers, {[Tb2(DMSO)6][LCu]3·5CH3OH}n1 and {[Er2(DMSO)4][LCu]3·2DMSO·6CH3OH}n2 (DMSO = dimethyl sulfoxide), based on carboxyl-containing metalloligand LCu ([Cu(2,4-pydca)2]2−, 2,4-pydca = pyridine-2,4-dicarboxylate) and lanthanide ions (TbIII, ErIII), have been synthesized with inter-diffusion method and well characterized. Single-crystal X-ray diffraction studies indicates that 1 and 2 crystallize in the space group of P − 1 of the triclinic crystal system and show 3D frameworks, which are severally established by {Tb2} and {Er2} clusters bridging with LCu metalloligands. The whole frameworks of 1 and 2 illustrate the similar 6-connected single-nodal topology with the point symbol of {412·63}. The most structural difference between two coordination polymers is that 2 exhibits a twofold interpenetrated framework. Thermal analysis reveals that 1 and 2 have similar thermal behavior with the skeleton both collapse after 292 °C. Magnetic measurements suggest that 1 and 2 exhibit the weak antiferromagnetic properties, which may be due to the existence of crystal-field effects of LnIII ions and the contribution of orbital couplings between the spin centers.

Series of 3d-4f heterometallic coordination polymers: Structures, near-infrared luminescence and magnetic properties

A series of 3d-4f heterometallic coordination polymers (CPs), namely, Ln2(CuL)2(nipt)3(H2O)]⋅nH2O (Ln = Sm 1, Nd 2, Gd 3, for 1–2 n = 2, for 3 n = 1.6), [Yb2(CuL)4(nipt)3]·3.5H2O (4), [Pr2(NiL)(nipt)3(H2O)]⋅1.5H2O (5), [Sm2(NiL)(nipt)3(H2O)2]CH3OH⋅H2O (6), [Er2(NiL)2(nipt)3(H2O)2]⋅3H2O (7) (ML, H2L = 2, 3-dioxo-5, 6, 14, 15-dibenzo-1, 4, 8, 12-tetraazacyclo-pentadeca-7, 13-dien; H2nipt = 5-nitroisophthalic acid) were obtained by a solvothermal method and structurally characterized. Complexes 1–3 have 3,3,4,5-connected (3.4.5)(32.42.5.63.72)(42.63.8)(42.6) topological structure consisting of two different chains. 4 exhibits a two-dimensional (2D) heterometallic structure with 3-connected (63) topology. 5 displays a 2D framework formed by four-strand meso-helical chains and characterized by 6,6,4,4,4-connected (411.64)(412.63)(43.62.8)(45.6)2 topology. Compound 6 has 3,4,4,3-connected (43)(44.62)(42.124)(42.6) topological structure formed by three-strand meso-helical chains. In 7, two kinds of μ3-bridged nipt2− ligands together with NiL connect the eight-coordinated Er3+ ions to form a 2D structure, and the 2D layers are extended by μ2-bridged nipt2− into a three-dimensional (3D) microporous framework with 4,4,3,3-connected (4.62.83)2(4.82)2 topology. Interestingly, for 1, 2 and 4, CuL-sensitized the near-infrared emissions form Sm(III), Nd(III) and Yb(III) were firstly found under visible light irradiation. Moreover, the magnetic properties of 1, 2, 4 and 5 are also discussed.

Assembly of a New 2D Heterometallic 3d–4f Coordination Polymer Bearing Planar Tetranuclear Square Building Blocks

A new two-dimensional (2D) 3d–4f heterometallic coordination polymer, which is {[Tb2Zn4(µ3-TFMIDC)4(µ4-HTFMIDC)(H2O)8]·2H2O}n, has been successfully synthesized by the solvothermal reaction of 2-(trifluoromethyl)-1H-4,5-imidazole dicarboxylic acid (H3TFMIDC) with Zn(II) and Tb(III) ions. The title compound was structurally characterized by diverse characterization techniques including single-crystal X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Single-crystal structure analysis reveals that the as-preprared compound is a 2D heterometallic 3d–4f coordination network based on interesting planar tetranuclear squares [Zn4(TFMIDC)4] as building blocks, representing the first example of novel heterometallic coordination polymer based on the H3TFMIDC ligand. In addition, the title compound exhibits very intense green luminescence and characteristic transitions of the Tb(III) ion when excited at 291 nm. Lattice parameters for the title compound: a = 11.1449(12) A, b = 12.8498(13) A, c = 37.553(4) A, α = β = γ = 90°, V = 5378.0(10) A3, Z = 4. A unique 2D 3d–4f heterometallic coordination polymer containing interesting planar tetranuclear square building blocks has been constructed by the solvothermal reaction of 2-(trifluoromethyl)-1H-4,5-imidazole dicarboxylic acid (H3TFMIDC) with Zn(II) and Tb(III) ions.

Lanthanide contraction and anion-controlled structure diversity in two types of novel 3d-4f heterometallic coordination polymers: Crystal structure and magnetic properties

Solvothermal reactions of isonicotinic acid (HIN) with lanthanide nitrate and cuprous halide yielded seven three-dimensional (3D) 3d-4f heterometallic coordination polymers (HCPs). These HCPs are formulated as {[NH2(CH3)2]2LnCu2Br(IN)6∙(DMA)2}n (Ln = Sm(1), Eu(2), Gd(3), Tb(4), Dy(5)) and [LnCu(IN)4∙DMA]n (Ln = Er(6), Yb(7)). Compounds 1–5 possess anionic three-dimensional pillared-layer frameworks with pcu topology, while compounds 6–7 show a rare 3d-4f dia-type two-fold interpenetrating framework with one dimensional square channels with side length of about 9.0 Å along the a axis. Crystal structure analysis reveals that the structure diversity is attributed to the synergistic effect of lanthanide contraction and halide anions. In addition, the magnetic properties of 1, 3, 4 and 5 were investigated.

Syntheses, Structures, and Magnetic Properties of Two Series of 3d–4f Heterometallic Coordination Polymers Derived from Pyrazine‐2,3‐dicarboxylic Acid

Twenty 3d–4f heterometallic coordination polymers (CPs), namely, [Ln2Co(2,3‐pzdc)4(H2O)6]·2H2O [Ln = La (1), Pr (2), Nd (3), Sm (4), Eu (5), Gd (6), Tb (7)], [Ln2Co(2,3‐pzdc)4(H2O)4]·4H2O [Ln = Dy (8), Er (9)], [Ln2Cu(2,3‐pzdc)4(H2O)6]·2H2O [Ln = La (10), Pr (11), Nd (12), Sm (13), Eu (14), Gd (15), Tb (16)], [Dy2Cu(2,3‐pzdc)4(H2O)4]·4H2O (17), and [Ln2Cu(2,3‐pzdc)4(H2O)4]·2H2O [Ln = Er (18), Yb (19), Lu (20)], are synthesized successfully by the reactions of 2,3‐H2pzdc with LnCl3·nH2O/Ln(NO3)3·nH2O and Co(NO3)2·3H2O/CuCl2·2H2O under hydrothermal conditions. CPs 1–20 are isostructural, and only the coordination and interstitial water molecules, as well as the coordination numbers of LnIII, are different from each other. In 1–20, the 2,3‐pzdc anions link the CoII/CuII and LnIII ions by two coordination modes to form a three‐dimensional (3D) framework with a 3,3,4,4‐connected (4·62)2(42·62·82)(63)2(65·8)2 topology. CPs 6 and 7 manifest the weak ferromagnetic interactions between CoII and LnIII in the low‐temperature range. CP 8 exhibits a field‐induced slow magnetic relaxation behavior. CP 16 shows a magnetic transition between short‐range ferromagnetic ordering at 60 K and long‐range ferromagnetic ordering below 26 K. CP 17 displays field‐induced single‐molecule magnet (SMM) behavior, with a Ueff value of 102.4 K.

Syntheses, Structures and Properties of 3d-4f Heterometallic Coordination Polymers Based on Tetradentate Metalloligand and Lanthanoid Ions

Based on tetradentate metalloligand LCu ([Cu(2,4-pydca)2], 2,4-pydca = pyridine-2,4-dicarboxylate) and lanthanides (Sm3+, Dy3+), two 3d-4fheterometalliccoordination polymers, namely, {[Sm2 (DMSO)4 (CH3OH) 2][LCu]3·7DMSO·2CH3OH}n 1 and {[Dy2 (DMSO)3 (CH3OH)][LCu3 (DMSO)]·4DMSO·CH3OH}n 2 (DMSO = dimethyl sulfoxide), have been synthesized and well characterized by elemental analysis, Fourier-transform infrared spectroscopy, thermogravimetric and single-crystal X-ray diffraction analysis. Single-crystal X-ray analysis reveals that both 1 and 2 crystallize in the triclinic crystal system with P-1 space group and possess the 3D framework structures, which are constructed from metalloligands LCu connecting with {Sm2} and {Dy2} clusters, respectively. The 3D structure of 1 has a 6-connected single-nodal topology with the point symbol {49 × 66}, while 2 features a different framework with the point symbol of {412 × 63}. Thermogravimetric analysis exhibits that the skeleton of both 1 and 2 collapse after 350℃. Magnetic properties of 1 and 2 have also been investigated.

Zn-Er heterometallic carboxylate framework based on 3,5-pyrazoledicarboxylic acid with nested sandwich structure and its luminescent property

A three-dimensional 3d-4f heterometallic coordination polymer, {[Er2Zn(Hpdc)4(H2O)8]·2H2O}n (1)(H3pdc=3,5-pyrazoledicarboxylic acid), was hydrothermally synthesized and characterized by techniques of single crystal X-ray diffraction, infrared spectra (IR), thermogravimetric analysis(TGA), elemental analysis, powder X-ray diffraction(PXRD), and luminescent measurements. X-ray crystal structure analyses reveal that complex 1 shows a 3D heterometallic framework with nested sandwich-type structure, built by the 2D Er-Hpdc networks, [Zn(Hpdc)2(H2O)2] units, and hydrogen bonds. In addition, the solid-state luminescent property investigation shows that emission lifetime span of the complex was at the microsecond level in the visible region, which is classified as a phosphorescent material. Moreover, when excited at 375nm, the complex exhibits the characteristic emission 4I13/2→4I15/2 of Er(III) at 1514nm.

Two 3d-4f Heterometallic Coordination Polymers of Macrocyclic Oxamide with Benzotriazole-5-carboxylate Co-ligand: Syntheses, Crystal Structures and Magnetic Properties

Two heterometallic 3d–4f coordination polymers, [Gd(CuL)2(Hbtca)(btca)(H2O)]·2H2O (1) and [Er(CuL)2(Hbtca)(btca)(H2O)]·H2O·CH3OH (2) (CuL, H2L = 2,3-dioxo-5,6,14,15-dibenzo-1,4,8,12-tetraazacyclo-pentadeca-7,13-dien; H2btca = benzotriazole-5-carboxylic acid) were synthesized by solvothermal methods and characterized by single-crystal X-ray diffraction. Complexes 1 and 2 exhibit a double-strand meso-helical chain structures formed by [LnIIICuII2] (LnIII = Gd, Er) units by oxamide and benzotriazole-5-carboxylate bridges. They are isomorphic except that one free water molecule of 1 is replaced by a methanol molecule. All 1D chains are further interlinked by hydrogen bonds resulting in a 3D supramolecular architecture. The magnetic properties of the compound 1 and 2 are also discussed.

Two novel 3d-4f heterometallic coordination polymers with infinite [Ln4(OH)4]n(8n+) chains involving in situ decarboxylation.

Two unique heterometallic {Ln4Co} coordination polymers with infinite Ln4(OH)4]n(8n+) chains have been successfully assembled, which represent the first example of heterometallic Ln-Co coordination polymers containing infinite lanthanide hydroxide chains.

Two dimensional porous 3d–4f heterometallic coordination polymers constructed by pyridine-2,3-dicarboxylic acid

Four porous CoIIILnIII 3d–4f heterometallic coordination polymers constructed by the pydcH2 ligand were hydrothermally synthesized and characterized. The adsorption and catalytic properties of compound CoIIIDyIII were investigated.

Two-dimensional 3d-4f heterometallic coordination polymers: syntheses, crystal structures, and magnetic properties of six new Co(II)-Ln(III) compounds.

Six new heterometallic cobalt(II)-lanthanide(III) complexes of formulas [Ln(bta)(H2O)2]2[Co(H2O)6]·10H2O [Ln = Nd(III) (1) and Eu(III) (2)] and [Ln2Co(bta)2(H2O)8]n·6nH2O [Ln = Eu(III) (3), Sm(III) (4), Gd(III) (5), and Tb(III) (6)] (H4bta = 1,2,4,5-benzenetretracaboxylic acid) have been synthesized and characterized via single-crystal X-ray diffraction. 1 and 2 are isostructural compounds with a structure composed of anionic layers of [Ln(bta)(H2O)2]n(n-) sandwiching mononuclear [Co(H2O)6](2+) cations plus crystallization water molecules, which are interlinked by electrostatic forces and hydrogen bonds, leading to a supramolecular three-dimensional network. 3-6 are also isostructural compounds, and their structure consists of neutral layers of formula [Ln2Co(bta)2(H2O)8]n and crystallization water molecules, which are connected through hydrogen bonds to afford a supramolecular three-dimensional network. Heterometallic chains formed by the regular alternation of two nine-coordinate lanthanide(III) polyhedra [Ln(III)O9] and one compressed cobalt(II) octahedron [Co(II)O6] along the crystallographic c-axis are cross-linked by bta ligands within each layer of 3-6. Magnetic susceptibility measurements on polycrystalline samples for 3-6 have been carried out in the temperature range of 2.0-300 K. The magnetic behavior of these types of Ln(III)-Co(II) complexes, which have been modeled by using matrix dagonalization techniques, reveals the lack of magnetic coupling for 3 and 4, and the occurrence of weak antiferromagnetic interactions within the Gd(III)-Gd(III) (5) and Tb(III)-Tb(III) (6) dinuclear units through the exchange pathway provided by the double oxo(carboxylate) and double syn-syn carboxylate bridges.

Synthesis, structure, photoluminescence and magnetism of 3d–4f heterometallic coordination polymers bearing benzimidazole-5,6-dicarboxylate

Hydrothermal reaction of rare earth oxides with 1H-benzimidazole-5,6-dicarboxylic acid (H3bidc) and MnSO4·H2O afforded a series of new three-dimensional (3D) coordination polymers, namely, [Ln2Mn(Hbidc)2(SO4)2·8H2O]n (Ln=Sm (1), Eu (2), Tb (3), Dy (4) and Ho (5)) and [Gd2Mn(Hbidc)2(SO4)2·7H2O]n (6). Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, FT-IR, powder X-ray diffraction and thermogravimetric analyses (TGA). The single-crystal X-ray diffraction analysis reveals that coordination polymers 1–6 have similar 3D frameworks fabricated through Hbidc2− and SO42− bridging dinuclear lanthanide secondary building units. Moreover, the photoluminescence of complexes 1–4 and magnetism of complexes 4 and 6 have been investigated, 4 exhibits remarkably slow magnetic relaxation behavior with the energy barrier ΔE/kB=83.3K.

A CuII–GdIII–CuII heterometallic coordination polymer constructed by gadolinium(III) ion and copper(II) Schiff-base building block: Structure and magnetic property

A new 3d–4f heterometallic coordination polymer [Gd(H2O)3(NO3−)(CuL)2] H2O (1) (H3L=glycylglycine, N-[1-(2-hydroxy, phenyl)-propylidene]) has been synthesized and characterized by IR, elemental analysis, TGA and X-ray single-crystal diffraction. In the coordination polymer, two metallo-ligand CuLs are connected with Gd3+ ion to form a 1-D chain via carboxylate and carbonyl oxygen. The neighboring Cu–Gd–Cu chains are further connected by hydrogen bonds to form a two-dimensional structure. Magnetic studies for 1 reveal that ferromagnetic interactions (JCuGd=1.30cm−1) between Cu(II) and Gd(III) centers are operating within the CuII–GdIII–CuII systems.

Hydrothermal Synthesis, Crystal Structure, and Luminescence Property of an Mn-Tb Complex Based on 5-(isonicotinamido)-isophthalate

A 3d-4f heterometallic coordination polymer, [Mn0.5Tb (INAIP)2(H2O)2]·2H2O (1) has been prepared by hydrothermal reactions of the corresponding lanthanide salt with 5-(isonicotinamido)isophthalic acid (H2INAIP) in the presence of MnSO4·H2O and NaOH. X-ray single-crystal structural analysis reveals that 1 features non-interpenetrated three-dimensional (3D) coordination framework containing two-dimensional (2D) (4, 4) Tb-carboxylate layers. In addition, 1 also displayed photoluminescent properties in the green range at room temperature.

Structures, luminescence and magnetic properties of three 3D lanthanide–zinc heterometallic coordination polymers based on 3-amino-1,2,4-triazole and Oxalate

Abstract Three 3D Ln(III)–Zn(II) 3d-4f heterometallic coordination polymers (HCPs) constructed from the coligands 3-amino-1H-1,2,4-triazole and oxalate, {[Ln2Zn19(atz)18(ox)9(Cl)8]·17H2O}n(Ln = Eu 1, Gd 2, Tb 3, Hatz = 3-amino-1H-1,2,4-triazole, ox = oxalic acid) have been synthesized under hydrothermal conditions and characterized by elemental analysis, FT-IR, TG analysis and X-ray diffraction. X-ray diffraction analysis reveals that these complexes are isostructural and feature 3D pillar-layered coordination frameworks constructed by the linkages of 2D layers and 1D zigzag chains, possessing a 5-nodal net topology with Schlafli symbol of {32;52;62}3{33;44;57;65;72}6{33;45;55;6;7}6{36;415;56;6}2{53}4. In addition, the magnetic property of 2 and the luminescence properties of 1 and 3 were also investigated.

Synthesis and magnetic properties of a 3d–4f heterometallic chain

A new 3d–4f heterometallic coordination polymer: [MnIIGd2III(OAc)8(H2O)4]·6H2O (1) (OAc−=acetate), has been conventionally synthesized and characterized by elemental analysis, IR, TG and single crystal X-ray diffraction. In 1, two Gd3+ and one Mn2+ cations are linked by carboxylic bridge of OAc− anions, giving a 1D 3d–4f heterometallic [MnIINd2III(OAc)8(H2O)4] chain. In the chain, there exist the short distances between the adjacent Gd(III) and Mn(II) ions as well as Gd(III) and Gd(III) ions, which make this 1D polymer displaying interesting magnetic properties.

Synthesis, structure characterization, and luminescent properties of two novel three-dimensional 4d–4f Ln–Ag coordination polymers based on two mixed ligands and zigzag [Ln2]n chains (Ln = Eu and Ho)

Two original three-dimensional (3-D) 4d–4f heterometallic coordination polymers, [Ln2Ag3(IN)5(OH)2(NO3)][NO3]·nH2O (Ln=Eu, n=2 (1); Ln=Ho, n=1 (2); HIN=isonicotinic acid), have been synthesized by hydrothermal assemble of Ln2O3 (Ln=Eu for 1; Ho for 2), HIN, AgNO3 and characterized by single-crystal X-ray diffraction, powder X-ray diffraction, IR spectroscopy, and thermogravimetric analysis (TGA). These two compounds show isostructural architectures and exhibit unusual 3-D open frameworks which are built upon the second ligand NO3- linking 2-D double wave-like [Ln2Ag2(IN)4(OH)2]n layers and Ag(IN) subunits. 1-D channel is found in the framework. And the luminescent properties of the two compounds have also been investigated.