Supported Transition Metal Complexes Research Articles

Enhanced Aquathermolysis of Water-Heavy Oil-Ethanol Catalyzed by B@Zn(II)L at Low Temperature.

In order to study the synergistic effects of exogenous catalysts and in situ minerals in the reservoir during heavy oil aquathermolysis, in this paper, a series of simple supported transition metal complexes were prepared using sodium citrate, chloride salts and bentonite, and their catalytic viscosity reduction performances for heavy oil were investigated. Bentonite complex catalyst marked as B@Zn(II)L appears to be the most effective complex. B@Zn(II)L was characterized by scanning electron microscopy (SEM), Fourier-Transform Infrared (FTIR) spectroscopy, thermo-gravimetric analysis (TGA) and N2 adsorption-desorption isotherms. Under optimized conditions, the viscosity of the heavy oil was decreased by 88.3%. The reaction temperature was reduced by about 70 °C compared with the traditional reaction. The results of the group composition analysis and the elemental content of the heavy oil indicate that the resin and asphaltene content decreases, and the saturated and aromatic HC content increases. The results of TGA and DSC of the heavy oil show that the macromolecular substances in the heavy oil were cracked into small molecules with low boiling points by the reaction. GC-MS examination of water-soluble polar compounds post-reaction indicates that B@Zn(II)L can diminish the quantity of polar substances in heavy oil and lower the aromatic nature of these compounds. Thiophene and quinoline were utilized as model compounds to investigate the reaction mechanism. GC-MS analysis revealed that C-C, C-N and C-S bonds were cleaved during the reaction, leading to a decrease in the viscosity of heavy oil.

A polyoxometalate supported copper dimeric complex: Synthesis, structure and electrocatalysis

A polyoxometalate (POM) supported copper dimeric complex, [Mo8O26{Cu2(2,2′-bpy)2 (CH3COO)2H2O}2]٠H4Mo8O26·16H2O (1) has been synthesized using conventional wet synthesis. The compound has been characterized using routine spectral techniques and its molecular structure has been elucidated using single crystal X-ray crystallography. The two copper(II) ions are bridged by acetate ions and each copper ion is also coordinated to 2,2′-bipyridine molecule. In each dimer, one of the copper ions is bonded to the POM anion from one side, whereas the other copper ion is bonded to a water molecule, hence acquiring a penta-coordinated square pyramidal structure around each copper center. The lattice water molecules play an important role to stabilize the system, by forming a water pentamer, which binds both the polyoxometalate supported transition metal complex and the other POM anion [Mo8O26]4–. Interestingly, compound 1 is found to function as a versatile heterogeneous electro-catalyst for water oxidation, proton reduction and hydrogen peroxide reduction.

Graphene Oxide Supported Oxovanadium (IV) Complex for Catalytic Peroxidative Epoxidation of Styrene: An Eye‐Catching Impact of Solvent

Graphene oxide (GO) supported transition metal complexes are apprised as sturdy and everlasting heterogeneous catalysts. GO surface was functionalized with 3‐triethoxysilylpropylamine (TSPA) and this amino functionalized GO (A‐f‐GO) nanocomposite with vanadyl Schiff base complex (VO‐f‐GO) was prepared and to give credence of its potentiality, it was chosen for the selective epoxidation of styrene using environmentally benign 30% H2O2 to styrene oxide (SO). To evade the detrimental exposure of “inborn” water, a selective high boiling and potent hygroscopic solvent, ethylene glycol was chosen to make this transformation productively successful. With the assistance of theoretical studies, we have probed the effect of H2O2 on to structural properties, binding mechanism and electronic properties of the catalyst and substrate. Adsorption energy (Ead), energy band gap (Eg) and HOMO‐LUMO were also calculated. Based on DFT calculations, resonance Raman and UV/Vis studies, we confirmed the formation of metal‐peroxo species and propose the plausible catalytic pathway. The influence of the diverse experimental parameters, like substrate to oxidant mole ratio, catalyst concentration, type of solvents, solvent amount, time, temperature and oxidant were tested. A clear relationship was found between different reaction parameters like solvent amount, oxidant, catalyst concentration and temperature etc. and product distribution. This heterogeneous catalyst yielded styrene oxide as nearly the sole product (selectivity = 98.7%) with a conversion value of 99.2% in the oxidation of styrene with hydrogen peroxide in ethylene glycol.

One Pot Synthesis of Luminescent Polyoxometalate Supported Transition Metal Complex and biological evaluation as a potential larvicidal and anti-cancer agent

Silicotungstate cluster coordinated organic-inorganic hybrid material [Cu(dmbpy)]2 [SiW12O40]·8H2O (1) known as polyoxometalate supported transition metal complex (POM-TMC) was synthesized simply in a one-pot reaction. The yield of the compound was significantly higher than the previous report. Larvicidal activity of 1 was investigated against dengue vector Aedes aegypti. A series of morphological changes in the mosquito larva was observed on exposure to different concentrations of the title compound. The total disintegration of the larva was observed at 50 μg/mL. In addition to the larvicidal activity, compound 1 exhibits anti-proliferative activity against the A375 human skin cancer cell line. PXRD pattern stimulated from single-crystal X-ray data was harmonized with PXRD of 1. Additionally, 1 was characterized by UV–Visible, Fluorescence, UV-DRS, FT-IR and Cyclic Voltammetry. Morphology of 1 was analyzed by Scanning Electron Microscopy (SEM). Composition of 1 was analyzed by Energy Dispersive X-ray SEM-EDX and Elemental analysis.

Reaction Conditions‐Dependent Formation of Catalytically Active Palladium Complexes or Palladium Nanoparticles on a Silica Support

AbstractSilica nanoparticles carrying covalently bound dipyridylmethylene (dpm) ligands were treated with Pd(OAc)2 in acetone in an attempt to prepare a silica surface‐immobilized Pd2+‐dpm complex. However, instead of the expected tethered complexes, small, monodisperse and evenly distributed palladium nanoparticles (PdNPs) formed. We found that an organic impurity, most likely an alcohol, in reagent‐grade acetone led to the reduction of Pd(OAc)2 to form PdNPs. The size and surface distribution of the PdNPs are affected by temperature, and formation of PdNPs can be inhibited by using high purity solvents and/or low temperature. The PdNPs supported on silica nanoparticles demonstrated catalytic activity in oxidation of benzyl alcohol to benzaldehyde, while silica nanoparticles with surface‐immobilized Pd2+‐dpm complexes required an induction period in order to reach a similar level of catalytic activity. In all cases, PdNPs were observed after the catalytic reaction, providing evidence that the induction period exhibited by the materials carrying Pd2+‐dpm complexes may be related to a time‐dependent PdNP formation process, with PdNPs rather than the immobilized complexes playing a central role in the catalytic reaction. Although nanoparticles are sometimes identified after carrying out catalytic reactions with supported molecular Pd complexes, our studies demonstrate the importance of identifying the species present in as‐synthesized heterogeneous materials of supported transition metal complexes.

Transition Metal Complexes On Insoluble Support And Their Applications In Transformations Of Organic Reactions

In this review we present some important recent work on the catalytic action of some supported transition metal complexes. Different types of synthesized heterogeneous transition metal catalysts including anchoring transition metal complexes on polymer or silica and zeolite encapsulated complexes are discussed, and an overview of their physicochemical characterization techniques are reported. The review is devoted to the catalytic applications of these host-guest materials towards the transformations of some organic reactions e.g. oxidation, epoxidation, hydrolysis, ring-opening…….etc. Key word: Supported transition metal complex catalysts; organic reactions.

ChemInform Abstract: Enantioselective Henry Reaction Catalyzed By Supported Transition Metal Complexes

AbstractReview: 45 refs.

Enantioselective Henry Reaction Catalyzed By Supported Transition Metal Complexes

This present mini-review summarizes the recently published development and trends concerning catalysts based on immobilized complexes of transition metals which are designated for asymmetric Henry reaction. The paper presents examples of originally homogeneous catalysts which were anchored to organic carriers (such as dendrimers, polymers) or inorganic materials. The catalysts based on organic carriers are classified and discussed in accordance to their solubility in reaction medium. In the case of inorganic materials, the discussed catalysts were anchored to different types of surface of micro- and nano-particles. The discussion concerns the effect of immobilization of catalysts on the overall reaction yield, enantioselectivity, possible recycling, and the effect of recycling on the abovementioned parameters.

Synthesis, structure, and catalytic activity of Keggin-type polyoxometalate coordinated Cu(I): {[Cu(py)2]4[SiW12O40]}, via hydrothermal decarboxylation

A Keggin-type polyoxometalate [SiW12O40]4− supported transition metal complex, {[Cu(py)2]4[SiW12O40]} (py = pyridine), has been synthesized by hydrothermal decarboxylation and characterized by elemental analyses, IR spectra, thermal stability analyses, and single-crystal X-ray diffraction. The compound is a 1-D chain containing an inorganic–organic backbone with alternating [SiW12O40]4− clusters and [Cu(py)2]+ along the c-axis, and with both three- and four-coordinate copper. The luminescence properties indicated that the emission peak is emission of pyridine, assigned to the Cu(I) to pyridine charge transfer. This air-stable Cu(I) complex can efficiently catalyze the O-arylation of both phenols and aryl halides.

Green Chemistry on Solid Support

R. Bruce Merrifield's Peptide Synthesis in 1963 using cross linked polystyrene support opened an exciting area of research and since then many new reagent bound, substrate bound and catalyst bound methods have been developed. Present paper discusses some work on the polystyrene-divinylbenzene supported transition metal complex catalysts in general and Ruthenium-schiff base complex in particular and its application in different reactions viz. Hydrogenation of styrene to ethylbenzene and oxidation of benzyl alcohol to benzaldehyde. The polymer bound complex was found to be more effective than homogeneous counterpart. Untapped potential of such catalysts is also discussed.

Polyoxometalate Supported Transition Metal Complexes: Synthesis, Crystal Structures, and Supramolecular Chemistry

A new series of polyoxometalate (POM) supported transition metal complexes (TMCs), namely, [2-ampH]4[{Zn(H2O)5}Mo7O24]·9H2O (1), [3-ampH]4[{Zn(3-ampy)(H2O)4}Mo7O24]·4H2O (2), [3-ampH]4[{Co(3-ampy)(H2O)4}Mo7O24]·4H2O (3), [2,3-diampH]4[Co(H2O)6][Mo7O24]·6H2O (4), and [2,3-diampH]2[{Zn(2,3-diampH)2(H2O)2}Mo8O27]·2H2O (5) have been synthesized (where amp = aminopyridine and diamp = diaminopyridine) from the corresponding aqueous sodium molybdate solution, by varying the transition metal salts and aminopyridine derivatives in an acidic medium. In compounds 1−4, the POM cluster is [Mo7O24]6−, whereas in compound 5, it is [Mo8O27]6−. In compound 1, the heptamolybdate moiety is functionalized by the zinc-aqua complex [Zn(H2O)5]2+ and the residual negative charges have been compensated by the protonated 2-aminopyridine molecules acting as cations. In the crystal structure of compound 1, a dimer of 2-aminopyridine has been identified as a supramolecular synthon. Compounds 2 and 3 are isomorphous, in which the POM cluster anion supports the zinc and cobalt coordination complexes, {Zn(3-ampy)(H2O)4}2+ and {Co(3-ampy)(H2O)4}2+, respectively. The overall negative charges of the resulting POM supported transition metal complexes in compounds 2 and 3 have been counter-balanced by the protonated 3-aminopyridine molecules. In compound 4, the anionic cluster unit [Mo7O24]6− exists as a discrete moiety, where the species {Co(H2O)4}2+ and protonated 2,3-diaminopyridine act as mere counter cations. Compound 5 is a two-dimensional (2-D) coordination polymer which is constructed by [Mo8O27]6− anion and [Zn(2,3-diampH)2(H2O)4]4+ cation moieties. In the crystal structure of 5, interestingly, a one-dimensional chain is formed by a condensation reaction among [Mo8O27]6− anionic cluster units through the formation of Mo−Ob−Mo (Ob is bridging oxygen) bonds, and these chains, in turn, are laterally interlinked by [Mo8O27]6− supported coordination complexes [{Zn(2,3-diampH)2(H2O)2}Mo8O27]2− (as linker) resulting in the formation of a 2-D porous network having well-defined cavities. All compounds 1−5, that are isolated at an ambient temperature, are characterized by single crystal X-ray crystallography and are additionally characterized by elemental analyses, infrared, thermogravimetric analysis/mass spectral studies. The crystal structures analyses of compounds 2, 3, and 5 show the existence of supramolecular tectons.

ChemInform Abstract: High Resolution 31P Solid State NMR in Phosphorus-Transition Metal Compounds

Abstract The use of a high resolution solid state 31 P NMR technique to investigate the coordination of phopshorus ligands bound to transition metal atoms is reviewed using examples which include information on molecular structure and crystallographic sites in organometallic solids, and characterization of supported transition metal complexes on surfaces. Moreover 31 P CPMAS (cross polarization magic angle spinning) experiments can afford a wealth of information such as chemical shift anisotropy, isotropic coupling constants with quadrupolar nuclei and quadrupole coupling constants that are often obscured in solution state due to the rapid isotropic motion of the molecules.

Hydrothermal Synthesis, Structure Characterization, Catalytic Property of Four Inorganic‐Organic Hybrid Phosphomolybdates

AbstractFour new inorganic‐organic hybrid polyoxometalate compounds based on the {Mo6P4} unit have been hydrothermally synthesized from the reaction of MoO3, Co(CH3COO)2·4H2O, triethylenetetramine (TETA) and 50 % phosphorus acid, and characterized by IR, TG, ICP and single‐crystal X‐ray diffraction. Compound 1 (H4TETA)2[(CoIITREN)2CoIIMoV12P8O52(OH)10]·4H2O [TREN = tris(2‐aminoethyl)amine], which is obtained at pH = 8.9, represents a {Mo6P4} unit supported transition metal complex, in which the CoII atom is pentacoordinate by four nitrogen atoms from TREN and one oxygen atom from PO4 tetrahedron, and the other CoII atom joins two {Mo6P4} units together to form a dimer by sharing six μ3‐O atoms. Compound 2 (H4TETA)2(C6H18N3)2[CoIIMoV12P8O54(OH)8]·5H2O [C6H15N3 = N‐(2‐aminoethyl)piperazine] obtained at pH = 6.4 shows a dimer anion [CoIIMoV12P8 O54(OH)8]14–, two fully protonated TETA and two protonated N‐(2‐Aminoethyl)piperazine. Compounds 3 [H4TREN]4[CoIIMoV12P8O56(OH)6]·4H2O and 4 [H4TETA]2[CoIIMoV12P8O48 (OH)14]·4H2O obtained from lower pH conditions (4.5 for 3 and 3.1 for 4) exhibit the same dimer anion as compound 2 only different cations. As the secondary building unit, the discrete dimer anions in compound 1–4 and the TETA (or its derivatives) construct 3D structures by hydrogen bonding interaction. The guest water molecules are filled in the channels, and also involved in the hydrogen bonding with oxygen atoms from inorganic‐organic hybrid framework, which makes the structures more stable. The catalytic properties of the four compounds are also tested in the styrene oxidation with H2O2.

Novel N,N,O Scorpionate Ligands and Transition Metal Complexes Thereof Suitable for Polymerisation

AbstractEsterification of 2,2‐bis(3,5‐dimethylpyrazol‐1‐yl)‐3‐hydroxypropionic acid (2) with methacryloyl chloride led to the new κ3‐N,N,O ligand 2,2‐bis(3,5‐dimethylpyrazol‐1‐yl)‐3‐methacrylato‐propionic acid (Hbdmpzmp) (3). The κ3‐N,N,O coordination as known from bis(3,5‐dimethylpyrazol‐1‐yl)acetic acid (Hbdmpza, 1) was proven by syntheses of the complexes [Mn(bdmpzmp)(CO)3] (4) and [Re(bdmpzmp)(CO)3] (5) and the single‐crystal X‐ray structure of 4. The methacrylic ester functionality makes 3, 4 and 5 suitable for polymerisation. Thus, copolymerisation of 3 with methyl methacrylate (MMA), a combination of MMA and ethylene glycol dimethacrylate (EGDMA) or pure EGDMA led to various solid phases (P1a–P1c, P2, P3a, P3b) with incorporated ligand. Polymer‐bound manganese and rhenium tricarbonyl complexes could be obtained by copolymerisation of 4 and 5 with MMA as well as by a polymer analogous reaction of P1a with appropriate metal salts. In both cases, the facial tripodal binding behaviour was evidenced by IR spectra of the polymer supported transition metal complexes and the uptake of manganese was proven by AAS measurements. Reaction of the soluble deprotonated solid phase P1a with copper(II) chloride led to a deep‐blue solid phase (P‐Cu‐I). The UV/Vis absorption maximum at 715 nm indicates the copper centres to act as crosslinking agent by a similar binding behaviour as in [Cu(bdmpza)2]. In contrast, the heterogeneous reaction of P1b with copper(II) chloride formed a lime‐green solid phase (P‐Cu‐II). The bathochromic shift of the absorption maximum by 78 nm suggests one‐sided bound copper centres. EPR spectra do not show exchange narrowing between the copper centres indicating the metal centres to be far enough apart from each other to prevent magnetic interactions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

Polymer supported catalysts for oxidation of phenol and cyclohexene using hydrogen peroxide as oxidant

Polymer supported transition metal complexes of N, N′-bis ( o-hydroxy acetophenone) hydrazine (HPHZ) Schiff base were prepared by anchoring its amino derivative Schiff base (AHPHZ) on cross-linked (6 wt%) polymer beads and then loading iron(III), copper(II) and zinc(II) ions in methanol. The loading of HPHZ Schiff base on polymer beads was 3.436 mmol g −1 and efficiency of complexation of polymer anchored HPHZ Schiff base for iron(III), copper(II) and zinc(II) ions was 83.21, 83.40 and 83.17%, respectively. The efficiency of complexation of unsupported HPHZ Schiff base for these metal ions was lower than polymer supported HPHZ Schiff base. The structural information obtained by spectral, magnetic and elemental analysis has suggested octahedral and square planar geometry for iron(III) and copper(II) ions complexes, respectively, with paramagnetic behavior, but zinc(II) ions complexes were tetrahedral in shape with diamagnetic behavior. The complexation with metal ions has increased thermal stability of polymer anchored HPHZ Schiff base. The catalytic activity of unsupported and polymer supported HPHZ Schiff base complexes of metal ions was evaluated by studying the oxidation of phenol (Ph) and epoxidation of cyclohexene (CH). The polymer supported metal complexes showed better catalytic activity than unsupported metal complexes. The catalytic activity of metal complexes was optimum at a molar ratio of 1:1:1 of substrate to oxidant and catalyst. The selectivity for catechol (CTL) and epoxy cyclohexane (ECH) in oxidation of phenol and epoxidation of cyclohexene was better with polymer supported metal complexes in comparison to unsupported metal complexes. The energy of activation for oxidation of phenol (22.8 kJ mol −1) and epoxidation of cyclohexene (8.9 kJ mol −1) was lowest with polymer supported complexes of iron(III) ions than polymer supported Schiff base complexes of copper(II) and zinc(II) ions.

Hydrothermal synthesis and crystal structure of a 1D fourfold-chain polyoxometalate-based complex [Cu(4,4′-bipy)] 2[SiW 12O 40{Cu(4,4′-bipy)} 4] · (OH) 2 · H 2O

A novel Keggin unit supported transition metal complex [Cu(4,4′-bipy)] 2[SiW 12O 40{Cu(4,4′-bipy)} 4] · (OH) 2 · H 2O ( 1) (4,4′-bipy = 4,4′-bipydine) has been hydrothermally synthesized and structurally characterized by IR spectroscopy, TG analyses and single-crystal X-ray diffraction. The result of the X-ray crystallography analysis exhibits that four { Cu ( 4 , 4 ′ -bipy ) } n n + chains simultaneously connect with the [SiW 12O 40] 4− units via W–Ot–Cu bridges constructing an infinitely one-dimensional fourfold-chain structure.

Polymer Supported Schiff Base Complexes of Iron(III), Cobalt(II) and Nickel(II) Ions and their Catalytic Activity in Oxidation of Phenol and Cyclohexene

The polymer supported transition metal complexes of N,N′‐bis (o‐hydroxy acetophenone) hydrazine (HPHZ) Schiff base were prepared by immobilization of N,N′‐bis(4‐amino‐o‐hydroxyacetophenone)hydrazine (AHPHZ) Schiff base on chloromethylated polystyrene beads of a constant degree of crosslinking and then loading iron(III), cobalt(II) and nickel(II) ions in methanol. The complexation of polymer anchored HPHZ Schiff base with iron(III), cobalt(II) and nickel(II) ions was 83.30%, 84.20% and 87.80%, respectively, whereas with unsupported HPHZ Schiff base, the complexation of these metal ions was 80.3%, 79.90% and 85.63%. The unsupported and polymer supported metal complexes were characterized for their structures using I.R, UV and elemental analysis. The iron(III) complexes of HPHZ Schiff base were octahedral in geometry, whereas cobalt(II) and nickel(II) complexes showed square planar structures as supported by UV and magnetic measurements. The thermogravimetric analysis (TGA) of HPHZ Schiff base and its metal complexes was used to analyze the variation in thermal stability of HPHZ Schiff base on complexation with metal ions. The HPHZ Schiff base showed a weight loss of 58% at 500°C, but its iron(III), cobalt(II) and nickel(II) ions complexes have shown a weight loss of 30%, 52% and 45% at same temperature. The catalytic activity of metal complexes was tested by studying the oxidation of phenol and epoxidation of cyclohexene in presence of hydrogen peroxide as an oxidant. The supported HPHZ Schiff base complexes of iron(III) ions showed 64.0% conversion for phenol and 81.3% conversion for cyclohexene at a molar ratio of 1∶1∶1 of substrate to catalyst and hydrogen peroxide, but unsupported complexes of iron(III) ions showed 55.5% conversion for phenol and 66.4% conversion for cyclohexene at 1∶1∶1 molar ratio of substrate to catalyst and hydrogen peroxide. The product selectivity for catechol (CTL) and epoxy cyclohexane (ECH) was 90.5% and 96.5% with supported HPHZ Schiff base complexes of iron(III) ions, but was found to be low with cobalt(II) and nickel(II) ions complexes of Schiff base. The selectivity for catechol (CTL) and epoxy cyclohexane (ECH) was different with studied metal ions and varied with molar ratio of metal ions in the reaction mixture. The selectivity was constant on varying the molar ratio of hydrogen peroxide and substrate. The energy of activation for epoxidation of cyclohexene and phenol conversion in presence of polymer supported HPHZ Schiff base complexes of iron(III) ions was 8.9 kJ mol−1 and 22.8 kJ mol−1, respectively, but was high with Schiff base complexes of cobalt(II) and nickel(II) ions and with unsupported Schiff base complexes.

A new α-keggin unit coordinated to two cobalt complex moieties {PMoVI 11MovO40[Co(TATP)2(H2O)]2}·4H2O

A new α-Keggin unit supported transition metal complex, {PMoVI 11MoVO40 [Co(TATP)2(H20)]2} · 4H2O (1) (TATP = 1,4,8,9-tetranitrogen-trisphene), has been hydrothermally synthesized and characterized by single crystal X-ray diffraction. X-Ray analysis showed that the two [Co(TATP)2(H2O)] units are covalently bonded to the α-Keggin unit [PMoVI 11MoV04o]4− via the terminal oxygen atoms. 1 represents the α-Keggin type polyoxoanion coordinated with two transition metal complex moieties, which further acts as a neutral molecular unit to construct an interesting 3D supramolecualr framework.

A new grid network based on diphosphopentamolybdate cluster supported transition metal complexes

A new grid architecture built from diphosphopentamolybdate supported copper-imidazole, [{CuII(im)4}2{H2Mo5P2O23}] · 3H2O · (im) (1) (im = imidazole), is reported. The structure of 1 features a 2-D grid network built by the interconnection of bisupporting diphosphopentamolybdate clusters, [{CuII(im)4}2{H2Mo5P2O23}]; free water molecules and imidazole ligands fill the void of the crystal lattice. Crystal data for compound 1: Orthorhombic, space group Pnma, a = 14.598(3) Å, b = 21.059(4) Å, c = 16.609(3) Å, α = β = γ = 90°; V = 5106.1 Å3; Z = 4.

A Water Pipe Held Up by a Polyoxometalate Supported Transition Metal Complex: Synthesis and Characterization of [Cu2(phen)2(CH3COO)(CH3COOH)(H2O)2][Al(OH)6Mo6O18]·28H2O

AbstractA water pipe, formed exclusively from lattice water molecules, is stabilized in an organic–inorganic hybrid materialCu2(phen)2(CH3COO)(CH3COOH)(H2O)2][Al(OH)6Mo6O18]·28H2O (1). Compound 1 consists of an Anderson‐type heteropolyanion, a copper acetate dimer, and 28 lattice water molecules. Once the relevant crystal is removed from the mother liquor it loses water molecules, which results in the demolition of the water pipe. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)