Two 3D coordination polymers constructed from flexible desymmetric carboxylate and neutral nitrogen ligands

Two coordination polymers based on a flexible desymmetric ligand precursor H₂L have been synthesized, that is, [Ni(L)(dpe)_3/2] H₂O (1), [Ni₂(H₂O)(L)₂(bpp)₂] H₂O (2), [H₂L = 4,4′-(phenylazanediyl)dibenzoic acid, dpe = 1,2-di(pyridin-4-yl)ethane, bpp = 1,3-di(pyridin-4-yl)propane]. These complexes were characterized by elemental analysis, IR spectroscopy, X-ray single-crystal and power diffraction. In addition, the second nonlinear optical properties of 2 were measured.     

Metal ions directed self-assembly based on rigid polycarboxylate ligand 5-tert-butyl isophthalic acid and flexible N-heterocyclic ligand 1,4-bis(2-methylimidazol-1-ylmethyl)-2,3,5,6-tetramethylbenzene

Two new complexes {[Cd(bmimx)_0.5(tbip)(H₂O)] · H₂O}_n (1) and [Zn(bmimx)(tbip)]_n (2) (bmimx = 1,4-bis(2-methylimidazol-1-ylmethyl)-2,3,5,6-tetramethylbenzene, H₂tbip = 5-tert-butyl isophthalic acid) based on mixed ligands have been hydrothermally synthesized by varying the metal ions. Structural analysis reveals that complex 1 displays a 2D layer structure with a 4⁴-sql topology; complex 2 exhibits a 3D 4-fold interpenetrated framework with sra topology. The structural differences between 1 and 2 indicate that metal ions have significant effects on the formation of the final architectures. In addition, the thermal stabilities and photoluminescent properties of the two complexes were also investigated.     

Synthesis,structures, luminescent and magnetic properties of four coordination polymers based on biphenyl-2,4′,5-tricarboxylic acid and different N-donor ligands

Four new coordination polymers [Zn(HL)(bibp)]_n (1: H₃L = biphenyl-2,4′,5-tricarboxylic acid, bibp = 4,4′-bis(imidazolyl)biphenyl), [Co(HL)(bibp)]_n (2), [Co(HL)(bib)]_n·4nH₂O (3: bib = 1,4-bis(1-imidazoly)-benzene), [Co_1.5(L)(bib)_1.5(H₂O)]_n·3nH₂O (4), have been synthesized under solvo/hydrothermal conditions, and have been fully characterized by single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), IR spectra, elemental analysis and thermogravimetric analysis (TGA). Structural analyses reveal that both 1 and 2 display a 4-fold interpenetrated framework. Complex 3 possesses a 2D (4,4) network. Complex 4 exhibits a 3D framework with the point symbol of {3²·4·6⁷}₂{3²·6¹⁰·7²·8}. Moreover, photoluminescence properties of 1 and magnetic properties of 2–4 have also been studied in detail.     

Novel luminescent heterobimetallic Ln–Cu(I) 3D coordination polymers based on 5-(4-pyridyl) isophthalic acid as heteroleptic ligand. Synthesis and structural characterization

Six novel photoluminescent Ln–Cu(I) heterobimetallic 3D coordination polymers, [LnCu (pyip^2 −)₂(H₂O)]_n (1–6) (where Ln is Pr, Nd, Sm, Eu, Gd, Ho, respectively, and H₂pyip = 5-(4-pyridyl) isophthalic acid) have been synthesized in a concise and reproducible manner under hydrothermal conditions. All of these substances were fully characterized by appropriate spectroscopic methods and elemental analysis. Structural determinations revealed that 1–6 are isomorphic and display 3D frameworks. Luminescent properties of the obtained compounds have been studied in detail revealing light emissions of warm white, cool white and light blue for 3, 4 and 5, respectively. The effectiveness of association of a rare earth with a transition metal in producing valuable luminescent materials for practical applications is demonstrated.     

Two novel 3D self-threading coordination polymers with CdSO4 topology: Syntheses,structures and properties

Two new isostructural metal-organic frameworks, namely [Co(HL)(bpp)] · 0.5H₂O (1) and [Zn(HL)(bpp)] · 3H₂O (2) (H₃L = 5-(2′-carboxy-biphenyl-4-ylmethoxy)-isophthalic acid, bpp = 1,3-bis(4-pyridyl)propane), have been hydrothermally synthesized and further characterized by single crystal X-ray diffraction, powder X-ray diffraction, elemental analyses, IR spectra and TG analyses. Compounds 1 and 2 exhibit interesting 3D frameworks of (6⁵.8)-CdSO₄ topology with dangling arm (i.e. the uncoordinated 2′-carboxy-biphenyl-4-ylmethoxy group of HL ligand). The remarkable feature of these two compounds is that each dangling arm threads into two 6-membered rings belonging to the 3D net itself, displaying the self-threading character. The magnetic properties of 1 and photoluminescence of 2 have also been investigated.     

Two 2D new helical coordination polymers induced by in situ hydrolysis generated 5-((pyridin-3-yl)methylcarbamoyl)pyridine-2-carboxylate

Solvothermal reaction of N,N′-Bis[(pyridin-3-yl)methyl]pyridine-2,5-dicarboxamide (L¹) as well as Zn(OAc)₂ or Co(NO₃)₂ in methanol gave rise to two new 2D complexes [Zn(L²)₂]_n (1) and [Co(L²)₂]_n (2), in which in situ formation of an anionic ligand 5-((pyridin-3-yl)methylcarbamoyl)pyridine-2-carboxylate (L²) was observed. Single-crystal structural analysis reveals that 1 and 2 are isostructural, and the 2D helical networks are assembled from two different-handed strands with shared the common metal atoms. Fluorescent and thermal properties of complexes 1 and 2 are also investigated.     

Ionothermal syntheses of two coordination polymers constructed from 5-sulfoisophthalic acid ligands with 1-n-butyl-3-methylimidazolium tetrafluoroborate ionic liquid as solvent

Two coordination polymers, namely, [Co(IM)₆][Co₂(SIP)₃] (1) (IM = imidazole, H₃SIP = 5-sulfoisophthalic acid) and [BMIM]₂[Cd₂(SIP)₃] (2) (BMIM = 1-n-butyl-3-methylimidazolium) were synthesized in ionothermal reactions by using ionic liquid 1-n-butyl-3-methylimidazolium tetrafluoroborate as solvent. Single-crystal X-ray analyses revealed that 1 has an anionic 1D polymeric chain charge balanced by an uncommon [Co(IM)₆]²⁺ cation. Complex 2 features an anionic 2D layer containing unique tetranuclear [Cd₄(CO₂)₆(SO₃)₂] cluster wherein the four Cd atoms are co-planar. The imidazolium cation [BMIM]⁺ of the ionic liquid acting as charge compensating agent intercalated into the [Cd₂(SIP)₂]^2n? interlayers in structure 2. The rich ionic environments of the ionic liquid may be particularly helpful in the formation of the anionic frameworks of 1 and 2.     

Anion-directed assembly of two fluorescent Cd(II) coordination polymers with a versatile multidentate N-donor building block 3-(2-pyridyl)-4,5-bis(4-pyridyl)-1,2,4-triazole

Assembly of Cd(II) nitrate with a novel tripyridyltriazole building block 3-(2-pyridyl)-4,5-bis(4-pyridyl)-1,2,4-triazole (L¹) and pseudohalide anion dicyanamide (dca) or azide (N₃) yields two coordination polymers {[Cd(L¹)₂(dca)₂](H₂O)₂}_n (1) and {[Cd₂(L¹)(μ_1,1-N₃)₂(μ_1,3-N₃)(N₃)](H₂O)_1.5}_n (2). Single crystal X-ray diffraction analysis indicates that the Cd(II) centers in 1 are bridged by the bidentate L¹ ligands to form 1D arrays, which are further extended to a 3D network via hydrogen bonding and aromatic stacking. Significantly, the L¹ ligands in 2 display the unusual pentadentate coordination and the azide anions take different μ_1,1-, μ_1,3-, and unidentate binding modes, interlinking the Cd(II) ions to afford a complicated 3D open framework with the inclusion of lattice water guests. Both complexes exhibit strong solid state fluorescent emissions at room temperature.     

Two novel 3D 3d–4f polymers with triethylenetetraaminehexaacetic acid: Syntheses,structures, and magnetic properties

Two novel 3d–4f polymers [La(H₂O)₄][M₂TTHA(SCN)₂] · H₃O⁺ (M = Ni(1), Cu(2), H₆ TTHA = triethylenetetraaminehexaacetic acid) were synthesized and characterized by X-ray single-crystal diffraction, elemental analysis, IR and magnetic properties. Two complexes show 3D framework, comprising an unusual infinite 1D chain based on heterometallic La₂M₂ rings (M = Ni(1), Cu(2)).     

Two new three-dimensional (3,4)-connected lanthanide (III) coordination polymers based on 2-(3-Pyridyl)-1H-imidazole-4, 5-dicarboxylate: Structures and luminescent properties

Two new lanthanide (III) coordination polymers, namely, {[Eu₃(μ₃-HPyIDC)₄]·Cl}_n, (1) and {[Tb₂(μ₃-HPyIDC)₂(μ₂-Ox) (H₂O)₂]·4H₂O}_n (2) (H₃PyIDC = 2-(3-Pyridyl)-1H-4, 5-imidazoledicarboxylic acid; Ox = oxalate), were successfully synthesized under hydro(solvo)thermal conditions and structurally characterized. Compound 1 displays a 3D framework with new (3,4)-connected {4.8.10}₄{4.8⁴.12}₂{4².8⁴} topology built by 3-connected μ₃-HPyIDC⁻ nodes and 4-connected metal ions. Compound 2 exhibits a rare (3,4)-connected dmc topology, in which μ₃-HPyIDC⁻ anions are 3-connected nodes and metal ions are 4-connected nodes. Moreover, the thermal stabilities and luminescence of compounds 1–2 were also investigated.     

Two rod-based 3-D lead(II) tetrafluoroterephthalate coordination frameworks with sra topology: Syntheses, structures, and properties

Two three-dimensional (3-D) Pb^II coordination frameworks [Pb(BDC-F₄)(CH₃OH)]_n (1) and [Pb(BDC-F₄)(DMF)(CH₃OH)]_n (2) have been prepared by the reactions of Pb(NO₃)₂ with a rigid dicarboxyl compound tetrafluoroterephthalic acid (H₂BDC-F₄) in different solvents. Single crystal X-ray diffraction reveals that both complexes show the unusual rod-based coordination networks with sra topology, although they crystallize in different space groups (C2/c and ). Their spectroscopic, thermal, and fluorescence properties have also been studied.     

Solvent-controlled assemblies,structures, and properties of two Hg(II) coordination polymers with a multidentate N-donor tecton 3,4-bis(2-pyridyl)-5-(4-pyridyl)-1,2,4-triazole

Coordination polymers [Hg(L²)Cl₂]_n (1) and {[Hg₂(L²)Cl₄](DMF)}_n (2) have been assembled from Hg(II) chloride and a novel tripyridyltriazole tecton 3,4-bis(2-pyridyl)-5-(4-pyridyl)-1,2,4-triazole (L²) in different solvent media. Both complexes have been characterized by IR, microanalysis, powder X-ray diffraction, and thermogravimetric analysis. Single crystal X-ray diffraction indicates that the L² ligands take the (η³, μ₂) and (η⁴, μ₃) binding modes in 1 and 2, respectively, which connect the Hg(II) centers to afford linear and ladder-like 1D arrays. Interestingly, complex 1 exhibits strong solid state fluorescent emission at room temperature due to the intraligand transitions, whereas complex 2 is non-fluorescent.     

Assembly of one 2D layer and two 3D pillared-layer structures derived from metal ions and 5-(pyridin-4-yl)isophthalic acid with or without pillars

Three new coordination polymers, [Mn(L)(H₂O)₂]₂·5H₂O (1), [Cu(L)(4,4′-bipy)]₂·H₂O (2) and [Pb(L)(4,4′-bipy)_0.5] (3) (H₂L = 5-(pyridin-4-yl)isophthalic acid; 4,4′-bipy = 4,4′-bipyridine) have been synthesized and characterized by IR, thermogravimetric analysis, X-ray powder diffraction and X-ray single crystal diffraction. Complex 1 shows a 2D layer structure which stacks with the other ones to form 1D channels to hold 1D water chains. Complex 2 displays a 3D + 3D → 3D polycatenation network. 3 shows a unique 2D + 2D → 3D polycatenation net in which each Pb center has a hemidirected coordination geometry due to the existence of “inert pair effect”. The thermal and luminescent properties of 1–3 were also examined.     

The novel polymeric potassium complex with a new coordination mode of orotic acid [K(μ5-H2Or)(μ-H2O)]n: Synthesis and structural characterization

Novel polynuclear seven-coordinated potassium complex, [K(μ₅-H₂Or)(μ-H₂O)]_n(H₃Or = orotic acid), with the new coordination mode of orotic acid has been prepared and characterized by elemental analysis, FT-IR spectra, X-ray diffraction. The orotate ligand exhibits new coordination mode of μ₅-κO, O: κO′, O′: O″ for H₂Or⁻.