Hexanuclear 4d–4f complexes [Ln2Ag4(ina)8(H2O)10][NO3]2 · 4H2O (Ln = Sm, Eu, Dy): Syntheses, structures and photoluminescent properties

Hexanuclear 4d–4f heterometallic complexes, [Ln₂Ag₄(ina)₈(H₂O)₁₀][NO₃] ₂ · 4H₂O [Ln = Sm (1), Eu (2), Dy (3) and Hina = isonicotinic acid], have been synthesized by the hydrothermal reaction of lanthanide oxides, Ag^I, and isonicotinic acid at a suitable temperature. Single-crystal X-ray diffraction studies indicate that these 4d–4f complexes consist of extended 1D zigzag chains structure built upon [Sm₂Ag₄(ina)₈(H₂O)₁₀] subunits connected by Ag–Ag interactions. Furthermore, the photoluminescent properties of the complex 2 were studied.     

Construction of three-dimensional Ln–Ag (Ln = Eu; Tm) coordination polymers based on isonicotinate and oxalate ligands

Hexanuclear 4d–4f heterometallic coordination polymers, [Ln₂Ag₄(IN)₅(ox)₂(NO₃)(H₂O)₂ · 3H₂O] [Ln = Eu (1), Tm (2); IN = isonicotinate and ox = oxalate], have been synthesized by hydrothermal reaction of mixed organic ligands and metal salts. Both structures display the same unusual 3D heterometallic coordination frameworks based on rare zigzag lanthanide–oxalate–silver chains, Ag₂(IN)₃ units and IN linkers. The photoluminescent properties of complex 2 were studied.     

Synthesis, structures, and photoluminescent properties of 3D lanthanide coordination polymers with rare (4,5)-connected topology

Three lanthanide coordination polymers, [Ln(Hpdc)(ox)_0.5(H₂O)₂]·H₂O (Ln = Nd(1), Eu(2), Er(3)) (H₃pdc = 3,5-pyrazoledicarboxylic acid, ox = oxalate), have been synthesized by the hydrothermal reaction of lanthanide nitrates, 3,5-pyrazoledicarboxylic acid, and oxalic acid (H₂ox) and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. Single-crystal X-ray diffraction studies indicate that complexes 1–3 are isomorphous and exhibit three-dimensional metal–organic frameworks with uncommon (4,5)-connected topology, which contain open channels occupied by the lattice water molecules. The photoluminescent properties of complex 2 were also studied.     

Four novel lanthanide(III) coordination polymers with 3D network structures containing 2-fold interpenetration

Four novel lanthanide(III) coordination polymers [Ln(L)_1.5(H₂O)₂]·5H₂O [Ln = Sm (1), Eu (2), Tb (3), Dy (4)] have been hydrothermally synthesized by the reaction of 1,2-bis[4-amino-5-carboxylmethylthio-(1,2,4-triazol-3-yl)]ethane (H₂L) with lanthanide(III) salts, and structurally characterized by single crystal X-ray diffraction. Polymers 1–4 are isostructural, in which all the Ln^III atoms are nine-coordinated and the carboxylate groups adopt three different coordination modes (bidentate chelate, bidentate bridging, bidentate chelate bridging) to connect Ln^III atoms. These polymers exhibit 3D network structures with 2-fold interpenetration, in which intriguing 1D channels are observed. Besides, the spectra properties of the title polymers are investigated, the strong luminescence characteristics of 2–3 are found.     

Three cobalt (II) complexes with triethylenetetraaminehexaacetic acid: From binuclear complex to 3d-4f coordination polymers

The cobalt(II)–lanthanide(III) heteronuclear complexes [Ln(H₂O)₄Co₂(TTHA)(SCN)₂]·H₃O⁺ (H₆TTHA = triethylenetetraaminehexaacetic acid, Ln = La(2), Ce(3)) have been synthesized based on a binuclear building block of [Co₂(H₂TTHA)(H₂O)₂] in [Co₂(H₂TTHA)(H₂O)₂]·4H₂O (1). Single-crystal structures show that complex 1 is a binuclear complex, containing the [Co₂(H₂TTHA)(H₂O)₂] unit as a useful building block. Adding the La^3 + and Ce^3 + ions to this synthesis system, two new 3d-4f mixed complexes 2 and 3 were obtained. Complexes 2 and 3 show 3D framework, comprising an infinite 1D (one-dimensional) chain based on heterometallic Ln₂Co₂ (Ln = La(2), Ce(3)). Further investigations such as IR spectra, UV–vis spectra, TGA, XRD and magnetic properties were studied.     

Crystal structures and luminescent properties of two novel coordination polymers containing Ln and

Two novel lanthanide–sulfate coordination polymers with chelidamic acid (H₃CAM): {[Ln₂(HCAM)₂(H₂O)₂SO₄] · 2.5H₂O}_n (Ln = Dy (1) and Tb (2)) have been synthesized under hydrothermal condition. 1 and 2 crystallize in the monoclinic space group P2₁/c. An intriguing bowl-like structure was constructed by three Ln³⁺ ions, one anion and carboxylate O bridges, in which the pentadente mode of anion are observed, and the structure as a repeating unit was assembled into a 1D chain. The luminescent properties of 1 and 2 are studied and exhibit the characteristic bands of the corresponding lanthanide ions.     

Construction of isostructural Ln–Ag (Ln = Eu; Tb; Dy) nano-channel heterometallic coordination frameworks based on pyrazine-2-carboxylate and oxalate ligands

The self-assembly of pyrazine-2-carboxylate and oxalate with mixed-metal salts under hydrothermal conditions gave three isostructural 3D 4d-4f coordination polymers, LnAg(ox)(2-pzc)₂ · H₂O [Ln = Eu (1); Tb (2); Dy (3)] [ox = oxalate, 2-pzc = pyrazine-2-carboxylate]. All three structures exhibit same unusual 3D nanoporous heterometallic coordination frameworks constructed by zigzag lanthanide–oxalate chains and Ag(2-pzc)₂ units. Furthermore, the luminescent properties of complexes 1 and 2 are discussed.     

Construction of two 2D 3d-4f coordination complexes based on the linkages of left-and right-handed helical chains

Two transition-lanthanide metal-organic coordination polymers, {[CoLn₂(Himdc)₂(SO₄)₂(H₂O)₄]·H₂O}_n [Ln = Yb (1), Ho (2)] (H₃imdc = imidazole-4, 5-dicarboxylic acid), have been synthesized by the hydrothermal reactions of lanthanide oxides, CoSO₄·7H₂O, H₃imdc and H₂O. Single-crystal X-ray diffraction analysis reveals that the isostructural complexes 1 and 2 possess unusual 2D wave-like heterometallic layers with 1D (Ln₂O₂CoO₂)_n and [Ln₂(SO₄)₂]_n inorganic chains constructed by the assembly of 1D left-/right-handed helical L–Ln₂Co–L (L = Himdc) chains and SO₄^2? anions, while a 3D framework is formed via hydrogen-bonding interactions interlayer.     

3D pillar-layered 4d–4f heterometallic coordination polymers based on pyridine-3,5-dicaboxylate and oxalate mixed ligands

Three 4d–4f heterometallic polymers, Ln₂Ag₂(Hpydc)₂(pydc)₂(ox) · 4H₂O (Ln = Nd (1), Eu (2) and Er (3); H₂Pydc = pyridine-3,5-dicarboxylic acid, H₂ox = oxalic acid), have been successfully synthesized under hydrothermal condition and structurally characterized. Single-crystal X-ray diffraction analyses reveal that three compounds are isomorphous and exhibit 3D pillar-layered coordination frameworks constructed from two-dimensional lanthanide-carboxylate layers and [Ag(pydc)]^? pillars. Furthermore, the luminescent property of compound 2 was studied.     

Solvothermal synthesis of 1D and 2D cobalt(II) and nickel(II) coordination polymers with 2,5-dihydroxy-p-benzenediacetic acid

1D cobalt(II) and nickel(II) coordination polymers {[Co(dba)(H₂O)₄] · H₂O}_n (1) and {[Ni(dba)(H₂O)₄] · H₂O}_n (2) (H₂dba = 2,5-dihydroxy-p-benzenediacetic acid) were synthesized under low temperature solvothermal condition. When 4,4′-bipyridine (bpy) was introduced to the synthetic systems of 1 and 2, respectively, two novel 2D coordination polymers {[Co(dba)(bpy)] · 0.5H₂O}_n (3) and [Ni(dba)(bpy)(H₂O)₂]_n (4) with different structures were obtained. All of the compounds were characterized by elemental analysis, FT-IR, UV–Vis spectra and single crystal X-ray diffraction.     

A hemidirected 1-D coordination polymer [Pb2(H2O)2(HBTC)2] · 3H2O extended in holodirected 3-D by weak Pb–O interactions

A new complex, [Pb₂(H₂O)₂(HBTC)₂] · 3H₂O (H₃BTC = 1,3,5-Benzenetricarboxylic acid) (1), has been synthesized under hydrothermal condition. The single-crystal analysis shows that 1 consists of 1-D double-chains with Pb(II) six-coordinated by three H₃BTC and one H₂O molecule with the Pb–O bond distances in the range of 2.56–2.76 Å. When the Pb–O bonding limit extends from 2.76 to 2.90 Å, the potential weak bonds of Pb–O can be found and the coordination number of Pb will increase from six to nine. As a result, the coordination geometry of Pb(II) transforms from hemidirected to holodirected and an infinite 3-D framework is obtained by the connection of the double-chains. The IR spectrum and the TGA–DTA curve of 1 are also reported in this paper.     

A 3D Gd–Ag coordination polymer constructed from pyridine-3,5-dicarboxylic acid: Synthesis, crystal structure and magnetic properties

A novel heterometallic coordination polymer, [AgGd(PDC)₂]·2H₂O (1) (H₂PDC = pyridine-3,5-dicarboxylic acid), have been synthesized under hydrothermal conditions, and characterized by elemental analysis, IR, thermogravimetric analysis and single-crystal X-ray diffraction. Complex 1 features an unusual three-dimensional network structure in which infinite gadolinium-carboxylate chains are linked by [Ag(PDC)₂]³⁻ metalloligands to form a mixed-metal coordination network. Moreover, the luminescent properties and magnetic properties of 1 have also been investigated.     

Two novel Zn(II) coordination polymers based on trigonal ligand: 4′-(4-pyridyl)-3,2′:6′,3″-terpyridine

Two novel Zn(II) coordination polymers, [Zn₅(pytpy)₈(fum)₄(H₂O)₄(OH)₂]_n · n(CH₃OH) · 2n(H₂O) (1) and [Zn₃(pytpy)₄ (btc)₂]_n · 2n(H₂O) (2) (pytpy = 4′-(4-pyridyl)-3,2′:6′,3″-terpyridine, H₂fum = fumaric acid, H₃btc = 1,3,5-benzenetricarboxylic acid) have been hydrothermally synthesized and structurally characterized. Complex 1 is a 2D layer structure, which is constructed from linear pentanuclear Zn(II) subunits interconnected via bidentate-bridging pytpy ligands and tridentate-bridging fum²⁻ anions. Complex 2 is a 3D network structure, μ₂-pytpy ligands link the layers based on the heart-like hexanuclear subunits to form the 3D network. Both complexes show strong fluorescence emission upon excitation at 310 nm in solid state. Additionally, these two complexes possess great thermal stabilities, especially for 2, the framework is stable up to 350 °C.     

Hydrothermal syntheses and crystal structures of four novel lanthanide(III) complexes based on two mixed N,O-donor ligands

Four novel polymeric lanthanide(III) complexes [Pr(NCP)(2,5-pydc)]_n·1.5nH₂O (1), [La(NCP)(2,5-pydc)]_n (2), [Nd(NCP)(2,5-pydc)]_n (3) and [Sm(NCP)(2,5-pydc)]_n (4) (HNCP = 2-(4-carboxyphenyl)imidazo(4,5-f)(1,10)phenanthroline, 2,5-H₂pydc = pyridine-2,5-dicarboxylic acid) have been hydrothermally synthesized and characterized via elemental analysis and single crystal X-ray diffraction. Structural analyses revealed that all of these four complexes possess similar two-dimensional sheet structures, which are further linked by the hydrogen bonds to furnish three-dimensional supramolecular structures. Meanwhile, the thermogravimetric analysis and photoluminescent property of complexes 1–4 have also been investigated.     

Isostructural 3D Ln–Ag (Ln = Eu; Dy; Ho) coordination frameworks based on mixed nicotinate and oxalate ligands: Synthesis,crystal structures and luminescence

By control of mixed organic ligands with different geometries, three unusual 4d–4f heterometallic coordination polymers, [AgLn(nic)₂(ox)] · 2H₂O [Ln = Eu (1); Dy (2); Ho (3)] [nic = nicotinate; ox = oxalate] have been synthesized under hydrothermal reaction. Three structures represent 3D open heterometallic coordination frameworks that are constructed from rare zigzag lanthanide-ox-silver chains and nic linkers. Furthermore, the luminescent property of complex 1 was discussed.     

A novel chiral 3D architecture containing left-handed helical chains constructed from vanadate clusters: [Zn(bpp)V2O6] (bpp = 1,3-di-4-pyridylpropane)

The hydrothermal reaction of Zn(NO₃)₂ · 6H₂O, bpp and NH₄VO₃ in water at 140 °C for 80 h yields an unprecedented chiral three-dimensional vanadium oxide complex, [Zn(bpp)V₂O₆] (1). The structure of 1 consists of wave-like two-dimensional networks, linked through {ZnO₂N₂} building blocks and bpp ligands into a three-dimensional covalently linked assembly. Furthermore, the title compound consists of infinite helical chains and all helical chains are left-handed.     

3D Ln–Ag (Ln = Nd; Eu) coordination polymers based on N- and O-donor ligands: Synthesis, crystal structures and luminescence

The self-assembly of isonicotinic acid with metal salts under hydrothermal conditions gave two isostructural 3D 4d–4f coordination polymers, Ln₂Ag₄(OX)(IN)₆(H₂O)_1.5 · 2(ClO₄) [Ln = Nd (1); Eu (2), OX = oxalic acid, IN = isonicotinic acid]. Compounds 1 and 2 are 3D coordination frameworks via 2D layers built by carboxylate groups of isonicotinic acid and oxalate ligands coordinating to metal centers and completing the linear linker by silver ions. Furthermore, the luminescent properties of complex 2 have also been investigated.     

Three unprecedented high-connected 3D lanthanide–organic frameworks based on benzene-1,2,4,5-tetracarboxylic acid

Three unprecedented high-connected 3D lanthanide coordination polymers based on benzene-1,2,4,5-tetracarboxylic acid (H₄bta), {[Ln₂(bta)_1.5(H₂O)₄] · 3H₂O}_n (Ln = La (1) and Ce (2)) and [Pr(bta)_0.5(H₂bta)_0.5(H₂O)]_n (3), have been synthesized under hydrothermal conditions. Complexes 1 and 2 show trinodal (4,4,10)-connected 3D network structures consisting of tetranuclear metal clusters bridged by bta^4 − ligands, and a chair conformation hexamer water cluster can be found within the cage enclosed by eight neighboring tetranuclear metal clusters in the two complexes. While 3 consists of 2D {Pr(bta)_0.5}_n layers linked by H₂bta^2 − ligands, resulting in an unprecedented trinodal (4,6,10)-connected 3D topological network. The organic ligand exhibits five kinds of coordination modes, in which one of them is reported for the first time. Moreover, the luminescent properties of 1–3 have also been investigated.     

Novel lanthanide coordination polymers with Eu-compound exhibits warm white light emission: Synthesis,structure, and magnetic properties

Five two-dimensional lanthanide coordination polymers: [Ln₂(TDA)₃(bipy)₂(H₂O)₂]·bipy·2H₂O (Ln = Nd (1), Sm (2), Eu (3), Tb (4), Yb (5), TDA = thiophene-2,5-dicarboxylic acid anion, bipy = 2,2′-bipyridine) were fabricated and structurally characterized. Compounds 1–5 are isostructural belonging to the triclinic system with space group P-1. Luminescence analyses were performed on coordination polymers containing Eu^3 + and Tb^3 +, and compound 3 shows a warm white light emission upon excitation.     

A novel three-dimensional 3d–4f heterometallic coordination polymer with unique (3,4)-connected topology and helical units: Synthesis,crystal structure and photoluminescence property

One new three-dimensional 3d–4f heterometallic coordination polymer, namely, {[EuZn₂(imdc)₂(C₂O₄)_0.5(H₂O)₄]·2H₂O}_n (1) (H₃imdc = imidazole-4,5-dicarboxylic acid), has been successfully synthesized by the hydrothermal reactions of Eu₂O₃, Zn(NO₃)₂·6H₂O, H₃imdc, H₂C₂O₄·2H₂O and H₂O. Single-crystal X-ray diffraction analysis reveals that complex 1 possesses 3D heterometallic framework containing 2D layer based on L–Zn2–L (L = imdc) helical chains and L–EuZn1–L chains. Complex 1 exhibits unprecedented (3,4)-connected four-nodal topology with Schläfli symbol (6·7·8) (6·7·9) (6·7²·8²·10) (7·8²). Moreover, the photoluminescence property of 1 was investigated in the solid-state at room temperature.