Assembly of heterometallic clusters and coordination polymers by combining Mo-S-based clusters with Mn2+

Addition of [Mo(V)2O2S2(edt)2]2- (edt =1,2-ethanedithiolate) to acetonitrile and/or methanol solutions of MnII containing bipyridines [4,4'-trimethylenedipyridine (TDP), 4,4'-bipyridine (4,4'-bpy), 2,2'-bipyridine (2,2'-bpy)] or 15-crown-5 produces three new heterometallic cluster coordination polymers, [Mn2[Mo2O2S2(edt)2]2(TDP)3(CH3OH)2(NCMe)2].3CH3OH.0.25MeCN (1), [Mn(TDP)2(H2O)2]2+[Mn[Mo2O2S2(edt)2)2(TDP)2]]2-.6CH3OH (2), [Mn[Mo2O2S2(edt)2](TDP)2(CH3OH)(H2O)].CH3OH (3), and three new multinuclear clusters, [Mn[Mo2O2S2(edt)2](4,4'-bpy)(CH3OH)4].0.5(4,4'-bpy) (4), [Mn[Mo2O2S2(edt)2](2,2'-bpy)2].2CH3OH (5), and (NEt4)2[Mn(15-crown-5)[Mo2O2S2(edt)2]2] (6). All compounds were characterized by X-ray crystallography. The coordination mode of Mn in these compounds depends on the ligands and the crystallization conditions. Compound 2 readily converts to 1 or 3 depending on the reaction and solvent conditions. Compounds 1 and 2 were analyzed using thermogravimetric analysis combined with mass spectroscopy (TG-MS) in the temperature range 25-500 degrees C. The room-temperature magnetic moments for compounds 1-6 were determined.     

Structure of glutarate-containing uranyl coordination polymers with organic amides

Three new uranyl complexes [UO₂(C₅H₆O₄)(Meur)] (I), [UO₂(C₅H₆O₄)(Aa)] (II), and [(UO₂)₂(C₅H₆O₄)₂(Tmur)₂(H₂O)] ? H₂O (III), where C₅H₆O₄ ^2? is glutarate anion, Meur is methylcarmamide, Aa is acetamide, and Tmur is tetramethylcarbamide, have been synthesized and characterized by X-ray diffraction. 1D uranyl-glutarate complexes have been found in the structures of all compounds; in I and II their composition is [UO₂(C₅H₆O₄)(L)] and crystallographic formula is AQ²¹M¹ (where A = UO₂ ²⁺, Q²¹ = C₅H₆O₄ ^2-, and M¹ = L = Meur or Aa). In crystals III, chain complexes have the composition [(UO₂)₂(C₅H₆O₄)₂(Tmur)₂(H₂O)] and crystallographic formula A₂Q₂ ⁰²M₃ ¹ (where A = UO₂ ²⁺, Q⁰² = C₅H₄O₆ ^2-, and M¹ = Tmur or H₂O). All compounds were characterized by IR spectroscopy. Structural features of all known complexes of uranyl glutarate with neutral ligands have been discussed.     

New semiconducting coordination polymers from zinc sulfide clusters and chains

Two new semiconducting zinc coordination polymers, Zn(8)S(SPh)(14)(bpy) (1) and Zn(2)(SPh)(4)(bpy) (2), have been synthesized by a dual-ligand approach. Single-crystal structural analyses indicate that compound 1 has a helical-chain structure with P1 clusters bridging with bipyridyl (bpy) ligands and compound 2 possesses a layered structure with zinc sulfide chains cross-linked with bpy ligands. The diffuse-reflectance spectra reveal that the band gaps of the two compounds are 2.41 eV for 1 and 2.56 eV for 2.     

Luminescent lanthanide coordination polymers with transformative energy transfer processes for physical and chemical sensing applications

The photophysical process of lanthanide(III) ion is based on the 4f-4f transition, which is the Laporte forbidden with narrow emission band and long emission lifetime. The 4f-4f emission process is affected by introducing aromatic organic ligands. In this review, recent progress of one-, two-, and three-dimensional polymer-typed lanthanide complexes, luminescent lanthanide coordination polymers, are focused for physical and chemical sensing applications. Their changeable luminescence depended on the physical and chemical environments come from the energy transfer between lanthanide(III) ions and aromatic organic ligands. The characteristic physical (temperature, pressure, pH and mechanical force) and chemical (adsorption of metal ions and molecules) sensitive luminescence of lanthanide coordination polymers are useful for future sensing applications.     

Three coordination polymers built from planar tetranuclear clusters and 5-sulfoisophthalic acid

Three coordination polymers built from planar tetranuclear clusters and H₃sip ligands, Pb₂Cl(sip)(bipy) (1), Pb₂Br(sip)(H₂O) (2), and Ni₄(sip)₂(pyz)₂(H₂O)₈(OH)₂·2H₂O (3) (H₃sip?=?5-sulfoisophthalic acid, bipy?=?2,2′-bipyridine, and pyz?=?pyrazine), have been hydrothermally synthesized and characterized by IR, TGA, and single-crystal X-ray diffraction. Compound 1 features a 2-D layer-like structure containing tetranuclear square [Pb₄(SO₃)₂] clusters. Complex 2 has a 3-D open framework architecture constructed from tetranuclear cluster [Pb₄Br₂(SO₃)₂] inorganic building blocks. The tetranuclear units, [Ni₄(OH)₂(COO)₄], in 3 are interlinked through carboxylates and µ₂-pyz ligands to generate a 2-D layer structure. The connecting modes between tetranuclear clusters and organic ligands in the three compounds are discussed in this article. In the solid state at room temperature, yellow photoluminescence in 1 and 2 are observed.     

Mixed-ligand coordination polymers constructed from flexible 2,2′-biphenyldicarboxylate and rigid isomeric bipyridines

Six coordination polymers have been synthesized and characterized based on dpa and isomeric bipyridine mixed ligands with various metal ions. Complex 1 exhibits a two-dimensional layer structure. Complex 2 is isomorphic to complex 1, with only small differences in bond lengths and bond angles. Complex 3 shows a one-dimensional chain structure composed of interesting pentanuclear Co building units. Complex 4 possesses a two-dimensional (4, 4) layer network, which crystallizes in a homochiral space group. During the synthesis process of complex 4, the dpa ligands decompose and form 2-bpa ligands, which connect with Ni atoms and produce the two-dimensional complex 5. Complex 6 exhibits a three-dimensional supramolecular structural feature constructed from discrete building units with π–π interactions. Furthermore, the magnetic properties of complex 2 are studied.     

One-dimensional coordination polymers containing penta-supertetrahedral sulfide clusters linked by dipyridyl ligands

Three new one-dimensional coordination polymers [Zn8S(SC6H5)14.C12H10N2](1), [Zn7CoS(SC6H5)14.C13H14N2](2) and [Zn8S(SC6H5)14.C13H14N2](3) have been prepared containing penta-supertetrahedral clusters and linear crosslinking dipyridyl ligands; the two complexes show optical transitions with band gaps of approximately 3.44 eV (1) and approximately 3.54 eV (2).     

Luminescent polymers with discrete emitter units

Optical absorption and photo-luminescence measurements were performed on a series of semiconducting polymers, based upon phenylene linkages, that have discrete emitter units. In these polymers, broken conjugation has been achieved in two ways: by introducing metalinkages between various numbers of para-connected aromatic groups or by severe steric distortion of a fully conjugated main chain. In either case, electronic states are localized on relatively small units, resulting in a large (π, π^*) band gap. The band gap decreases with increasing emitter unit conjugation, as expected. Blue light emission was observed from these materials, with the peak emission wavelength red shifted (by greater than 1 eV on average) from the peak absorption. © 1994 John Wiley & Sons, Inc.     

Luminescent sensors based on coordination polymers with adjustable emissions for detecting biomarker of pollutant ethylbenzene and styrene

Sensitive luminescent probes for phenylglyoxylic acid (PGA), which is a biomarker of ethylbenzene and styrene (EB/S) representing the internal dose of EB/S exposure, have been constructed on the basis of newly designed luminescent coordination polymers (LCPs). Three isostructural LCPs with different lanthanide centers were solvothermally synthesized and fully characterized. All the LCPs 1 – 3 display strong regulated emissions by the adjustable metal–organic coordination interactions. Among LCPs 1 – 3 , the fabricated LCP 2 can quantitatively detect PGA with the highest sensitivity in physiologically relevant ranges. The mechanism study of luminescent responses toward PGA further explains the excellent sensitivity and selectivity of LCP 2 for sensing PGA. The facile, accurate, fast, and recyclable sensing system relying on LCP materials provides a convenient approach for developing sensing platforms with adjustable emissions for assessment of the intoxication level of EB/S.     

Engineering with metallo-supramolecular polymers: linear coordination polymers and networks

Here we demonstrate the synthesis of telechelics with different spacer units and different numbers of metal-complexing units, like α-methoxy-ω-(2,2′:6′,2″-terpyrid-4′-yl)-poly(ethylenoxide)₇₈ ( 1 ), bis(2,2′:6′,2″-terpyrid-4′-yl) di(ethylene glycol) ( 2 ), bis(2,2′:6′,2″-terpyrid-4′-yl)-poly(ethylene oxide)₁₈₀ ( 3 ) and tris[(2,2′:6′,2″-terpyrid-4′-yl)-oligo (ethylenoxy-)_3.33]glycerin ( 4 ) utilizing 4-chloro-2,2′:6′,2″-terpyridine. The complexation behaviour of a variety of metal-salts towards the telechelics was studied and different supramolecular architectures were investigated, such as symmetric polymeric complexes and linear coordination polymers. Furthermore, attempts have been undertaken to prepare metallo-supramolecular cross-linked systems.     

A new free and immobilized pyrylogen electron transfer sensitizer

The synthesis, photophysical, and electrochemical characterization of N-allyl-2,6-diphenyl-4,4′-pyrylogen bis tetrafluoroborate is reported. The pyrylogen is reduced under dissolving metal reduction conditions with formation of the radical cation. In addition, it can be copolymerized with styrene and divinylbenzene to generate a polymer bound reagent that facilitates its separation from photochemically induced electron-transfer reaction mixtures.     

Phosphine-based coordination cages and nanoporous coordination polymers

Recent findings in the use of multidentate phosphines to synthesise porous coordination polymers (metal-organic frameworks) and their possible precursor cages are reviewed. Additional recent investigations into using large adamantoid Age cages as polymer vertices in giant diamandoid structures are also presented. The results are discussed in terms of possible strategies for the controled synthesis of porous coordination polymers.     

New inorganic/organic coordination polymers generated from bidentate Schiff-base ligands

The coordination chemistry of the long conjugated bidentate Schiff-base ligands 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene (L1) and 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene (L2) with cadmium and cobalt nitrate hydrates is investigated. Four new coordination polymers are prepared by solution reactions and fully characterized by infrared spectroscopy, elemental analysis, thermogravimetric analysis, and single-crystal X-ray diffraction. [Cd(NO3)2(L1)(1.5).0.5(L1)]n (1; monoclinic, P2(1)/c; a = 7.7729(16) A, b = 19.049(4) A, c = 17.865(4) A, beta = 93.13(3) degrees, Z = 4) is obtained by combination of L1 with Cd(NO3)(2).4H2O in a benzene/methanol or THF/methanol mixed-solvent system. The structure features two-dimensional brick wall sheets that are cross-linked by weak noncovalent pi-pi interactions (alternating face-to-face stacking of coordinated and uncoordinated L1 molecules) to generate a novel three-dimensional network. [Co(NO3)2(L1)(1.5).H2O]n (2; orthorhombic, Ccca; a = 19.031(4) A, b = 33.627(7) A, c = 14.299(3) A, Z = 4) is generated from the reaction of L1 with Co(NO3)(2).6H2O in a benzene/ethanol mixed-solvent system. It forms with a unique three-dimensional framework that can be considered a new polymeric motif based on the 1:1.5 metal-to-ligand composition M(L)1.5. The Cd(II) and Co(II) centers in 1 and 2, which lie in seven-coordinate environments, generate two new types of building blocks. The topologies of these two new building blocks are distinctly different from the common "T-shaped" building block generated from the same (MN3O4) coordination environment reported previously. Cd(L2)2(NO3)2 (3) and Co(L2)2(NO3)2 (4) are obtained by combination of L2 with Cd(NO3)(2).4H2O and Co(NO3)(2).6H2O, respectively. Compounds 3 and 4 are isostructural, crystallizing in the monoclinic space group P2(1)/n, with a = 8.5802(17) A, b = 17.506(4) A, c = 10.443(2) A, beta = 96.59(3) degrees, and Z = 2 for 3 and a = 8.5283(17) A, b = 17.408(4) A, c = 10.229(2) A, beta = 97.05(3) degrees, and Z = 2 for 4. 3 and 4 adopt a novel one-dimensional chain structural motif, consisting of M2(L2)2 (M = Cd, Co) ringlike units. O...H-C hydrogen-bonding interactions in both 3 and 4 play a significant role in aligning the polymer strands in the solid state.     

Yttrium coordination polymers with layered structures

A hydrothermal reaction of a mixture of Y(NO₃)₃·xH₂O, phthalic and isophthalic acid, and phthalic acid and terephthalic acid in the presence of 1,10-phenonthroline gave rise two new two-dimensional coordination polymer, Y₂(C₁₂N₂H₈)₂[(1,2-BDC)₂(1,3-BDC)], I, Y₂(C₁₂N₂H₈)₂[(1,2-BDC)₂(1,4-BDC)], II, respectively. Both structures were solved using single crystal X-ray diffraction studies. I and II consist of a one-dimensional chain formed by the connectivity between Y³⁺ and 1,2-BDC anion, and cross-linked by 1,3-BDC and 1,4-BDC anions to form the layer structure. The 1,10-phenonthroline molecule, bound to yttrium, project into the interlayer space and contribute to the structural stability through favorable π…π interactions. Room temperature photoluminescence studies indicate that both I and II show strong emission, with bathochromic and hypsochromic shifts with respect the acid and 1,10-phenonthroline.     

Entangled coordination polymers with mixed N- and O-donor organic linkers: a case of module-matching priority

A series of four coordination polymers showing entangled architectures based on cobalt and mixed N-donor/O-donor ligands, namely [Co(4,4'-BPIPA)(TP)]·2DMF (1), [Co(4,4'-BPIPA)(2,6-NDC)(DMF)]·DMF (2), [Co(4,4'-BPIPA)(2,6-NDC)]·2DMF (3) and [Co(4,4'-BPIPA)(4,4'-BPDC)]·2DMF (4) (4,4'-BPIPA = N,N'-bis-4-pyridinyl-isophthalamide, TP = terephthalic acid, 2,6-NDC = 2,6-naphthalenedicarboxylic acid, 4,4'-BPDC = 4,4'-biphenyldicarboxylic acid), have been synthesized under solvothermal conditions. Complex 1, containing 4,4'-BPIPA and relatively short dicarboxylate ligands (TP), exhibits two-dimensional (2D) two-fold interpenetration of double wavy 4(4)-sql nets. Complex 2 displays interesting 2D→3D parallel polycatenation of undulated 2D 4(4)-sql layers built by 4,4'-BPIPA and moderate dicarboxylate ligands (2,6-NDC). Complexes 3 and 4, although constructed of dicarboxylate ligands with different lengths (moderate 2,6-NDC and long 4,4'-BPDC), possess similar 3-fold interpenetration of identical self-catenated single nets with 6(5)·8-mok topologies. It has been found that the length of the dicarboxylate ligands plays a key role of module-matching in the self-assemblies of complexes 1-4. Moreover, the effect of the conformations of 4,4'-BPIPA, which can be controlled by tuning reaction temperatures, is also discussed.     

Stereospecific coordination ofl-hydroxyproline esters with triosmium clusters

The reactions of cluster (-H)Os₃(CO)₁₀(-OH) with ethyl and isopropyl esters ofl-oxyproline were studied. In the presence of Me₃NO intermediate complex (-H)Os₃(CO)₉(-OH)L (L — isopropyl ester ofl-oxyproline) is formed, which slowly converts to the more stable cluster (-H)Os₃(CO)₉ . Cluster complexes containing chelate-bridging heterocycles were also obtained by heating (-H)Os₃(CO)₁₀(-OH) with esters ofl-oxyproline. In both cases, only one of the possible diastereomeric complexes (-H)Os₃(CO)₉ (R = Et, Prⁱ) is formed, which indicates that the reactions are stereospecific. Based on analysis of Dreiding's models, an attempt to determine the absolute configuration of the obtained clusters was made.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2021–2025, October, 1995.     

Two highly-connected, chiral, porous coordination polymers featuring novel heptanuclear metal carboxylate clusters

Two novel (3,12)-connected, chiral porous coordination polymers featuring 3D intersecting pore structures, selective sorption and solvothermal resistance properties are constructed by linking 3-connected benzene-1,3,5-tribenzoic acid with two types of 12-connected heptanuclear metal carboxylate clusters.     

Optimised hydrothermal synthesis of multi-dimensional hybrid coordination polymers containing flexible organic ligands

In this paper, we summarise our recent research interest in the hydrothermal synthesis and structural characterisation of multi-dimensional coordination polymers. The use of N-(phosphonomethyl)iminodiacetic acid (also referred to as H₄pmida) in the literature as a versatile chelating organic ligand is briefly reviewed. This molecule plays an important role in the formation of centrosymmetric dimeric [V₂O₂(pmida)₂]⁴⁻ anionic units, which were first used by us as building blocks to construct novel coordination polymers. Starting with [V₂O₂(pmida)₂]⁴⁻ in solution, we have isolated [M₂V₂O₂(pmida)₂(H₂O)₁₀] species (where M²⁺ = Mn²⁺, Co²⁺ or Cd²⁺) via the hydrothermal synthetic approach, which were then employed for the construction of [CdVO(pmida)(4,4′-bpy)(H₂O)₂]·(4,4′-bpy)_0.5·(H₂O), [CoVO(pmida)(4,4′-bpy)(H₂O)₂]·(4,4′-bpy)_0.5, [Co(H₂O)₆][CoV₂O₂(pmida)₂(pyr)(H₂O)₂]·2(H₂O) and [Cd₂V₂O₂(pmida)₂(pyr)₂(H₂O)₄]·4(H₂O) by the inclusion of bridging organic ligands in the reactive mixtures, such as pyrazine (pyr) and 4,4′-bipyridine (4,4′-bpy). These materials can contain channel systems, and exhibit magnetic behaviour, not only due to the V⁴⁺ centres but also to the transition metal centres which establish the links between neighbouring dimeric [V₂O₂(pmida)₂]⁴⁻ anionic units. A closely related anionic moiety, [Ge₂(pmida)₂(OH)₂]²⁻, was engineered to allow the study of such crystalline hybrid materials using one- and two-dimensional high-resolution solid-state NMR.     

Supramolecular architectures and magnetic properties of coordination polymers based on pyrazinedicarboxylato ligands showing embedded water clusters

The synthesis, crystal structure, and magnetic behavior of nine transition-metal complexes based on pyrazine-2,5-dicarboxylato (pz25dc) and pyrazine-2,3-dicarboxylato (pz23dc) ligands are reported. The pz25dc ligand displays a bis-bidentate coordination mode, with the carboxylate groups almost coplanar with the pyrazine ring, to afford polymeric 1-D chains [Mn(1), Fe(2), Zn(3), and Cu(4 and 5)] and discrete dimeric entities [Mn(6)] when the 1,10-phenanthroline (phen) blocking ligand is used to avoid further polymerization. The nonplanar pz23dc ligand chelates to a unique copper center, while it bridges another one or two metal centers via the remaining carboxylate group, leading to 1-D polymeric chains (7), ladder chains (8), and sheets (9). The crystal packing of the metal-organic frameworks of compounds 4-9 generates voids which are occupied by assembled water molecules. The different water cluster patterns (tapes, four-membered discrete rings, and chains for compounds 6, 8, and 9, respectively) and their role in the cohesiveness of supramolecular architectures are analyzed. Thermogravimetric and variable-temperature X-ray powder diffraction studies have revealed the occurrence of reversible dehydration processes in compounds 6, 8, and 9. Furthermore, the magnetic behavior of these compounds has been studied in order to analyze the capability of the pyrazine ring to transmit magnetic interactions.