Synthesis, crystal structures and luminescent properties of zinc and manganese complexes from Demko-Sharpless reaction

The synthesis and crystal structure of two new complexes (Zn and Mn) containing tetrazolyl ligands are described. In situ [2+3] cycloaddition reactions of fipronil, (fipronil = (±)-5-amino-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-[(trifluoromethyl)sulfinyl]-1H-pyrazole-3-carbonitrile) with sodium azide in the presence of ZnCl₂ or MnCl₂ as a Lewis acid (Demko-Sharpless tetrazole synthesis method) under hydrothermal (solvothermal) reaction conditions gave [Zn(L)₂](H₂O)₂] · H₂O, 1 and [Mn(L)₂](H₂O)₂] · H₂O, 2, (HL = (±)-5-amino-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-[(trifluoromethyl)sulfinyl]-1H-pyrazole-3-tetrazole). The central metals in both complexes are six coordinated, which connected by two water molecules, two nitrogen atoms from different tetrazolyl groups and two nitrogen atoms from pyrazolyl rings respectively. Photoluminescence studies reveal that both title complexes exhibit strong blue fluorescent emissions at λ_max = 383 nm for 1 and 411 nm for 2 respectively in the solid state at room temperature.     

A new copper(II) tubelike metal-organic framework constructed from P,P′-diphenylmethylenediphosphinic acid and 4,4′-bipyridine: Synthesis, structure, and thermal behavior

A new tubular metal-organic framework [Cu₂(pcp)₂(4,4′-bipy)] · 5H₂O (pcp = P,P′-diphenylmethylenediphosphinate) has been synthesized and characterized by single-crystal X-ray analysis, temperature-dependent X-ray powder diffraction (TDXD), thermogravimetric measurements and IR spectroscopy. The structure consists of polymeric nano-sized square channels, whose edges are constituted by infinite chains of metal ions bridged by phosphinate ligands. The chains are linked together by 4,4′-bipyridines, forming the walls of the channels. Solvent water molecules are located inside and outside the channels, all anchored through hydrogen bonds. The cross-section dimensions of the channels are approximately 10 × 10 Å². The four guest molecules located inside the channels can be eliminated by gentle heating at ca. 80 °C, restored in air, or in turn substituted by DMF through vapour exposition. The monohydrated phase [Cu₂(pcp)₂(4,4′-bipy)] · H₂O, which maintains the same polymeric framework as the title complex, remains stable till 260 °C. Above this temperature the complex undergoes a solid state crystal-to-crystal rapid reaction, via loss of both the 4,4′-bipyridine and the remaining water and rearrangement of the coordinated pcp to give the previously reported [Cu(pcp)] polymeric framework.     

Chemistry of the binary mixture of 1,10-phenanthroline and zinc perchlorate hexahydrate in methanol and gas phase. Monohydroxo species and tricoordination of zinc and water clusters

ESIMS reveals that methanol solutions of 1:1, 1:2 and 1:3 mixtures of Zn(ClO₄)₂ · 6H₂O and 1,10-phenanthroline (phen) generate [Zn(phen)(OH)]⁺, [Zn(phen)(H₂O)₄(OH)]⁺, [Zn(phen)₂(H₂O)(OH)]⁺and [Zn(phen)₂(H₂O)₄(OH)]⁺ ions in the gas phase. DFT calculations at the B3LYP/LanL2DZ level show that zinc is planar tricoordinate in [Zn(phen)(OH)]⁺ and the cis configuration is more stable than the trans one for the hexacoordinate ion [Zn(phen)₂(H₂O)(OH)]⁺. DFT calculations also show that the [Zn(phen)(H₂O)₄(OH)]⁺ and [Zn(phen)₂(H₂O)₄(OH)]⁺ ions are actually [Zn(phen)(H₂O)(OH)]⁺ · 3H₂O and [Zn(phen)₂(H₂O)(OH)]⁺ · 3H₂O containing extended motifs of H-bonded water clusters. The aqua species corresponding to the monohydroxo ions are acidic. Their acid dissociations are modeled collectively by equilibrium (see below) where other ligands around Zn are not specified. An attempt is then made to estimate K_a

     

pH-value-controlled assembly of photoluminescent zinc coordination polymers

By pH-value adjustment, the reactions of zinc salt, 1,3,5-benzenetricarboxylic acid (H₃btc) and 4,4′-bipyridine (bpy) yield three coordination polymers, formulated as [Zn₃(btc)₂(bpy)(H₂O)₂]_n (1), [Zn(Hbtc)(bpy)(H₂O)]_n · 3nH₂O (2) and [Zn(Hbtc)(bpy)(H₂O)]_n · 4nH₂O (3), respectively. The structure of 1 is a 3D network containing channels filled with bpy ligands. Compound 2 consists of twofold interpenetrating (10,3)-b networks, while compound 3 is a 2D layer structure. The fluorescent studies reveal that they exhibit intense violet luminescence in solid state.     

Metal-organic open frameworks with one-dimension channels assembled with pyridine 2,6-dicarboxylic acid and N-containing auxiliary ligands: Syntheses, crystal structures, and physical characterization

Four new complexes, {[Mn(imH)₂(pdc)]·H₂O}_n (1), [Zn₂(pdc)₂(H₂O)₅]·2H₂O (2), [Zn(imH)₂(pdc)]·H₂O (3), {[Zn₂(pdc)₂(bpy)(H₂O)₂]·5H₂O}_n (4) [imH = imidazole pdc = pyridine 2,6-dicarboxylate, bpy = 4,4′-bipyridine] have been synthesized under hydrothermal conditions and structurally characterized by elemental analysis, IR, PXRD, single-crystal X-ray diffraction and thermogravimetric analyses. All the four complexes display a three-dimensional (3D) open framework with one-dimensional (1D) channels that are filled with lattice water molecules. Particularly, in 4, the lattice water molecules form an infinite water chain. Both 1 and 4 consist of 1D polymeric chains. While 2 contains a dinuclear Zn(II) unit, and 3 is a mononuclear complex. Further, the result of thermal analysis of 1 and 2 shows the robustness of the overall supramolecular three-dimensional architecture. Complexes 1, 3, and 4 exhibit strong fluorescent emissions in the solid state at room temperature and could be significant in the field of photoactive materials.     

Synthesis and crystal structure of one-dimensional zinc(II) polymer constructed by salicylate and trans-1,2-bis(4-pyridyl)ethylene

A new zinc(II) compound, [Zn₂(Hsal)₄(4,4′-bpe)₂] · [Zn(Hsal)₂(4,4′-bpe)(DMF)(H₂O)] · CH₃OH (1) (Hsal = salicylate and 4,4′-bpe = trans-1,2-bis(4-pyridyl)ethylene) has been synthesized and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, and single crystal X-ray diffraction. The crystal structure consists of three independent moieties: [Zn₂(Hsal)₄(4,4′-bpe)₂], [Zn(Hsal)₂(4,4′-bpe)(DMF)(H₂O)], and non-coordinated CH₃OH molecule. In the compound two independent moieties which are connected by 4,4′-bpe to form 1-D chains, respectively, are further expended to accomplish 2-D network through hydrogen-bonding interactions between non-coordinated methanol and coordinated water molecule or carboxylate oxygen atoms of Hsal ligands.     

Five-, seven-, and eight-coordinate Cd(II) coordination polymers built by anthranilic acid derivatives: Synthesis, structures and photoluminescence

Two novel Cd(II) coordination polymers, [(CH₃)₂NH₂]₂[Cd(cma)₂](H₂O) (1) and [Cd₃(bcma)₂(H₂O)](H₂O) (2) (H₂cma = N-(carboxymethyl)-anthranilic acid, H₃bcma = N,N′-bis-(carboxymethyl)-anthranilic acid), have been synthesized under hydrothermal conditions and characterized by X-ray single crystal analysis, IR spectra and TGA. Compound 1 possesses 1D double-stranded chain, which further packs into square channels. Compound 2 consists of a novel 3D framework, which not only possesses unique meniscus-like channels but also contains infinite helical chains. Compound 2 is the first example of Cd(II)-aminopolycarboxylate coordination polymers containing three crystallographically independent Cd(II) centres, in which Cd(1), Cd(2), and Cd(3) present distorted pentagonal bipyramidal, tetragonal antiprismatic, and trigonal bipyramidal coordination geometry, respectively. Both compounds display intense room temperature photoluminescence in the solid state.     

Synthesis and characterization of two new triazolate-aliphatic dicarboxylate bridged Zn(II) coordination polymers based on 2D layer motifs with different crystal packing

Two new zinc(II)-triazole-aliphatic dicarboxylate coordination polymers, [Zn(trz)(Hsuc)]_n (1), [Zn₂(trz)₂(tar)]_n (2), have been hydrothermally synthesized by reaction of Zn salt, Htrz with H₂suc and H₂tar, respectively (Htrz = 1,2,4-triazole, H₂suc = succinic acid, H₂tar = tartaric acid).Their structures were determined by single-crystal X-ray diffraction analyses and further characterized by X-ray powder diffraction, elemental analyses, IR spectra and TG analyses. Compound 1 displays a 2D layer structure containing {[Zn₄(trz)₄]⁴⁺}_n layers decorated by the suc ligand. Compound 2 is in a 3D structure formed by the interconnection of 2D {[Zn₄(trz)₄]⁴⁺}_n layers with tar ligand, resulting a 3,4-connected topological network. Due to the different coordination mode and conformation of aliphatic carboxylate ligand, the similar 2D {[Zn₄(trz)₄]⁴⁺}_n layers stack in the -AAA- fashion in 1, while the {[Zn₄(trz)₄]⁴⁺}_n layers hold together in the -ABAB- stacking sequence in 2. Additionally, the two compounds show strong fluorescence in the solid state at room temperature.     

The first lanthanide carboxylate complex constructed from hydroxyl bridging bimetallic units: Hydrothermal synthesis, crystal structure and luminescent properties

One novel terbium complex [Tb₂(Dinic)₂(phen)₂(OH)₂(H₂O)₂]_n · 3nH₂O (1) has been synthesized by hydrothermal method, where Dinic = 3,4-pyridinedicarboxylate and phen = 1,10-phenanthroline. X-ray crystallography reveals that complex 1 possesses a one-dimensional chain structure constructed from OH⁻ bridging binuclear units, and hydrogen bonding between chains result in a 3D network. The fluorescent properties of complex 1 were investigated in the crystal state.     

Double complex salts of Pt and Pd ammines with Zn and Ni oxalates - promising precursors of nanosized alloys

Double complex salts [M(NH₃)₄][M′(Ox)₂(H₂O)₂] · 2H₂O (M = Pd, Pt, M′ = Ni, Zn) were synthesized by combination of solutions containing corresponding cations [M(NH₃)₄]²⁺ and anions [M′(Ox)₂(H₂O)₂]²⁻. The salts obtained were characterized by IR spectroscopy, thermal analysis, powder and single crystal X-ray diffraction. The prepared compounds are isostructural and crystallize in the orthorhombic crystal system (space group I222, Z = 2). Thermal decomposition of the salts in helium or hydrogen atmosphere at 200-400 °C results in formation of nano-sized bimetallic powders. Depending on the phase diagram of the respective bimetallic system and temperature conditions, they can be single phase or multiphase products. In particular, thermal decomposition of double complex salts [M(NH₃)₄][Zn(Ox)₂(H₂O)₂] · 2H₂O (M = Pd, Pt) results in formation of PdZn and PtZn intermetallic compounds, correspondingly. Decomposition of [Pd(NH₃)₄][Ni(Ox)₂(H₂O)₂] · 2H₂O affords a disordered solid solution Pd_0.5Ni_0.5. Disordered Pt_0.5Ni_0.5 was obtained from [Pt(NH₃)₄][Ni(Ox)₂(H₂O)₂] · 2H₂O in helium atmosphere, while in hydrogen atmosphere - a two-phase mixture of disordered Pt_0.5Ni_0.5 and ordered PtNi. In all cases crystallite sizes of bimetallic particles varied within 50-250 Å.     

Zinc(II) and copper(II) 1D coordination polymeric complexes of a reduced Schiff base ligand

The reaction of Zn(ClO₄)₂ · 6H₂O and Cu(ClO₄)₂ · 6H₂O with H₃Sas (H₃Sas = N-(2-hydroxybenzyl)-L-aspartic acid in water afforded the complexes [Zn₆(Sas)₄(H₂O)₈]·5H₂O (1) and [Cu(HSas)(H₂O)] (2), respectively, which were characterized by infrared spectroscopy, elemental analysis, thermogravimetry and single-crystal X-ray crystallography. In 1, the pentanuclear clusters formed by four H₃Sas ligands and five Zn(II) metal ions are bridged by the “[Zn(H₂O)₄]²⁺” cations to form 1D polymeric chains. While in 2, the mononuclear [Cu(HSas)(H₂O)] repeating units form a 1D zigzag chain and further extended by strong intermolecular hydrogen bonds to form a 2D sheet. The different coordination geometries of Cu(II) and Zn(II) show significant influence on the polymeric structures.     

Group II metal-directed structural variation of coordination compounds derived from 5-[N-acetato(4-pyridyl)]tetrazolate ligand

Reactions of MCl₂ (M = Mg, Ca, Sr, Ba) and a4-ptz (a4-ptz = 5-[N-acetato (4-pyridyl)] tetrazolate) potassium salt in water, respectively, and produced four new complexes [Mg(H₂O)₆] · (a4-ptz)₂ · 2H₂O (1), [Ca(a4-ptz)₂(H₂O)₂]_n · 2nH₂O (2), [Sr(a4-ptz)₂(H₂O)₂]_n · 2nH₂O (3), [Ba₄(a4-ptz)₈(H₂O)₈]_n · 4nH₂O (4). These compounds were structurally characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. Compound 1 has mononuclear structure bearing distinct intermolecular hydrogen-bond interactions to form a three-dimensional supramolecular network. While compounds 2-4 have one-dimensional polymeric chains that are bridged by two water molecules linker, respectively. The luminescence properties of 1-4 were investigated at room temperature in the solid state.     

Synthesis, crystal structure and luminescence properties of two novel lanthanide coordination polymers containing double chain

Two novel lanthanide(III) two-dimensional (2D) coordination polymers [Ln₂(PDC)₂(OH)₂(H₂O)₂] · H₂O (Ln = Eu (1) and Tb (2), H₂PDC = pyridine-3,4-dicarboxylic acid) have been prepared under hydrothermal conditions and characterized by elemental analysis, IR, TGA and single-crystal X-ray diffraction. Compounds 1 and 2 crystallize in the triclinic system, space group , they are isostructural and exhibit the same two-dimensional topological network constructed by PDC-connected Ln-O-Ln double chains. Photoluminescence properties of the compounds 1 and 2 have been investigated in the solid state at room temperature.     

Metal(II)-organic coordination polymers with two distinct atropisomeric building units from an axially prochiral inner salt through interchain C-H?X hydrogen bonds (X = O, Cl; metal = cobalt, nickel)

Two isostructural photoluminescent metal-organic coordination polymers, namely, [M(H-mpypdc)(Cl)(H₂O)₃]_n (mpypdc = 2,6-dimethyl-4-(pyridin-4-yl)pyridine-3,5-dicarboxylate; M = Co (2) and Ni (3)), were synthesized from H₂mpypdc (1), and characterized by single crystal X-ray analyses. New ligand 1 is an inner salt. In the metal-organic coordination polymeric chains, two distinct S- and R-atropisomeric units are generated from the axially prochiral 1 through C-H?X (X = O, Cl) hydrogen bonds. There have interesting 2D supramolecular networks [M(Cl)(H₂O)₂]_n in the crystal structures of title compounds. The photoluminescence of new compounds are also investigated in solid state at ambient temperature.     

Photoluminescent metal(II)-organic complexes with two distinct atropisomeric units from axially prochiral ligands through C-H?O hydrogen bonds (M = zinc, cobalt, nickel)

By taking advantage of rich-electron modification of pyridine-3,5-dicarboxylates, three photoluminescent isostructural metal-organic complexes, namely, [M(Hsmpdc)₂(H₂O)₄] · 6H₂O (smpdc = 2,6-dimethyl-4-(thiophen-2-yl)pyridine-3,5-dicarboxylate, M = Zn (1), Co (2) and Ni (3)), were synthesized and characterized by single crystal X-ray analyses. There are interesting hydrogen-bonded M²⁺(H₂O)₈ ionic clusters in the structures of title compounds. And of the most interesting is that S- and R-atropisomeric units are constructed from axially prochiral organic ligands through C-H?O hydrogen bonds. Strong photoluminescent emission at 543 nm with obvious red shift might make compound 1 a potentially photoactive solid-state material for its thermal and chemical stability.     

Synthesis, crystal structures, and characterization of three coordination compounds constructed from 4-sulfophthalic acid ligand

Three new coordination compounds with 4-sulfophthalic acid (H₃SPA) ligand, namely {[Pb₃(4-SPA)₂(H₂O)](H₂O)}_n (1), [Mn(4,4′-bpy)₂(H₂O)₄][Mn₂(4-SPA)₂-(4,4′-bpy)₄(H₂O)₄]·7.5(H₂O) (2) and Cu₂(4-HSPA)₂(2,2′-bpy)₂(H₂O)₂ (3) (4,4′-bpy = 4,4′-bipyridine and 2,2′-bpy = 2,2′-bipyridine), have been synthesized. The structures exhibit different dimensionality depending on the nature of the metal ions and/or the ancillary ligands. Compound 1 has a 2D layered architecture constructed from one-dimensional inorganic lead(II) oxygen chains containing tetranuclear [Pb₄(μ₂-O)₄] cluster. Compound 2 has a dinuclear manganese [Mn₂(4-SPA)₂(4,4′-bpy)₄(H₂O)₄] motif charged with mononuclear [Mn(4,4′-bpy)₂(H₂O)₄]²⁺ cation. Compound 3 is a discrete dinuclear copper(II) structure that linked by extensive hydrogen bonds to form a three-dimensional supramolecular structure. In the solid state, compound 1 exhibits blue photoluminescence with the maximum at 432 nm upon excitation at 350 nm. The temperature-dependent magnetic susceptibility data of 2 have been investigated. The Curie constant C and Weiss constant θ are 3.14 emu K mol⁻¹ and −2.09 K, respectively, revealing antiferromagnetically magnetic interactions between the Mn²⁺ ions. In addition, these compounds are characterized by powder X-ray diffraction, IR, elemental analysis, and thermogravimetric analysis.     

Three zinc-organic frameworks based on 1,4-benzenebis(thioacetic acid): Syntheses, crystal structures, and luminescent properties

A new flexible aromatic multithiocarboxylate ligand: 1,4-benzenebis(thioacetic acid) (H₂L), was synthesized and introduced to construct three interesting metal-organic frameworks (MOFs) with the photoluminescent properties. Three MOFs were characterized by the elemental analysis, infrared (IR) spectrum, and single crystal X-ray diffraction. [Zn₃L₃(2,2′-bipy)₂]_n (1) is a two-dimensional (2D) layered architecture that consists of the linear trinuclear units of Zn atoms. [ZnL(2,2′-bipy)(H₂O)]_n·0.7nH₂O (2) is a one-dimensional (1D) helical chain, which further forms a 2D structure with 30-membered ring with a size of 7.64 × 15.53 Å via O−H···O hydrogen bonds. [ZnL(phen)(H₂O)]_n·0.35nH₂O (3) presents a 2D supramolecular network through the O−H···O interactions. Their thermal and photoluminescent properties in solid state were given.     

Cobalt(II) coordination polymers assembled from polycarboxylate and benzotriazole: Syntheses, structures and physical properties

Hydrothermal reactions of cobalt(II) salt with H₂CAM or H₂SDBA and HBTA in the presence of NaOH afford two interesting coordination polymers, Co₃(CAM)₂(BTA)₂ (1) and Co₃(SDBA)₂(BTA)₂ (2) (H₂CAM = camphoric acid, H₂SDBA = 4,4′-dicarboxybiphenyl sulfone, HBTA = benzotriazole), both of which have been structurally characterized by single-crystal X-ray, elemental analysis, infrared spectroscopy, and thermogravimetric analysis. Complexes 1 and 2 are isostructural and possess two-dimensional covalent network, comprising an unusual linear Co(II) chains of mixed T_d-O_h-T_d geometries. Temperature-dependent magnetic measurements indicate the existence of antiferromagnetic interactions in both 1 and 2.     

Self-assembly of four three-dimensional reduced molybdenum(V) phosphates decorated with transitional metal complexes

Four new three-dimensional materials built from reduced molybdenum(V) phosphates as building blocks and transitional metal (Co, Zn and Cd) complexes as linkers, (Hbpy)₂[Co(bpy)(H₂O)]₂[Co(H₂PO₄)₂ (HPO₄)₆(MoO₂)₁₂(OH)₆] (1), [Co(H₂O)₄]₂[Co(Hbpy)(H₂O)]₂[Co(bpy)][Co(HPO₄)₄(PO₄)₄(MoO₂)₁₂(OH)₆] · 6H₂O (2), Na₂[Zn(Hbpy)(H₂O)₂]₂[Zn(Hbpy)]₂[Zn(HPO₄)₂(PO₄)₆(MoO₂)₁₂(OH)₆] · 4H₂O (3), (H₂bpy)₂[Cd(bpy)(H₂O)]₂[Cd(bpy)(H₂O)₂]₂[Cd(HPO₄)₄(PO₄)₄(MoO₂)₁₂(OH)₆] · 2H₂O (4) (bpy = 4,4′-bipyridine), have been synthesized and characterized by elemental analyses, IR, TG, and single crystal X-ray diffraction. The 3-D framework of 1 is constructed from Co[P₄Mo₆]₂ dimers bonded together with [Co(bpy)]_n coordination polymer chains. In compound 2, the Co[P₄Mo₆]₂ dimers are linked by both [Co(bpy)] complex chains and the cobalt dimers to form a 3-D framework. Compounds 1 and 2 represent the first examples of reduced molybdenum(V) phosphates decorated with transition metal complexes chains. The 3-D framework of 3 is constructed from Zn[P₄Mo₆]₂ dimers bonded together with [Zn(bpy)] coordination complexes and [Zn(bpy)(H₂O)₂] complexes. In compound 4, the Cd[P₄Mo₆]₂ dimers are coordinated with [Cd(bpy)(H₂O)] and [Cd(bpy)(H₂O)₂] complexes to construct a 3-D structure. To our best knowledge, it is the first time that linear ligand 4,4′-bpy molecules have been grafted into the backbone of reduced molybdenum phosphates. Furthermore, the magnetic properties of compounds 1 and 2 are reported.     

Effect of tether length and counterion in cobalt-dipyridine coordination polymers prepared via hydrothermal methods

Hydrothermal synthesis afforded three new cobalt coordination polymers containing 1,2-di-4-pyridylethane (dpe) and 1,3-di-4-pyridylpropane (dpp), whose structures were determined by single crystal X-ray diffraction. Co(SCN)₂(dpe)₂ exhibits a one-dimensional chain-type structure with bound thiocyanate ligands. Co(NO₃)₂(H₂O)₂(dpp)₂ · dpp · H₂O also manifests one-dimensional chains, but with free nitrate ions and unbound dpp in the regions between the chains. Due to the increased tether length and conformational freedom of the organic moiety in Co(SCN)₂(dpp)₂, the material can adopt a doubly interpenetrated two-dimensional layered structure.