Hexanuclear Complex Research Articles

Preparation and structural characterization of the hexatungsten cluster complex (EDTEH)2[W6(?3-Cl)8Cl6], (EDTEH=(MeO2CCH2)2N(H)CH2CH2N(CH2CO2Me)2+

The hexanuclear tungsten cluster complex [W6(μ3-Cl)8Cl6]2−,1 was isolated as a salt of the cation (MeO2CCH2)2N(H)CH2CH2N(CH2CO2Me)2+, EDTEH+, by crystallization from methanol solvent of the product obtained from the reaction of (H3O)2[W6(μ3-Cl)8Cl3] with the disodium salt of ethylenediaminetetraacetic acid. The compound was charcterized by single-crystal X-ray diffraction analysis. The cluster anion contains an octahedral arrangement of six tungsten atoms with chloride ligands bridging the eight triangular faces of the cluster and one chloride ligand terminally coordinated to each of the six tungsten atoms. The cation (EDTEH)+ achieves its positive charge by protonation of one of the nitrogen atoms. Crystal data: space group = P21/a,a=10.689(2) A,b=22.931(6) A,c=12.093(3) A, β=98.41(2)°,Z=2, 2476 reflections,R=0.028.

Synthesis, crystal and molecular structure of calcium oxo ethoxide, [Ca6(µ4-O)2(µ3-OEt)4(OEt)4]·14EtOH

The hexanuclear complex of calcium oxo ethoxide ethanol solvate, [Ca6O2(OEt)8]·14EtOH 1 has been isolated after the prolonged refluxing of an ethanol solution of calcium ethoxide in the presence of the oxygen in air and studied by X-ray diffraction; the metal-oxygen framework is built of two [Ca4O4] cubes sharing a common [Ca2O2] face, which involves both oxo groups.

Synthesis and crystal structures of novel copper(I) co-ordination polymers and a hexacopper(I) cluster of quinoline-2-thione

Quinoline-2-thione (C9H7NS) reacted with [Cu(MeCN)4]+ in tetrahydrofuran to give infinite-chain copper(I) complexes [{[Cu(C9H7NS)2]X}∞](X = ClO41 or PO2F22) and [Cu6(C9H6NS)6]3. The crystal structures of all three have been determined. Complexes 1 and 2 are isomorphous and crystallize in space group P42/m, Z= 8 with a= 16.697(1), c= 6.438(2)A, and a= 16.713(5), c= 6.412(2)A, respectively. Only the thione sulfur is involved in co-ordination to copper(I), in a bridging mode. Each copper has a distorted-tetrahedral geometry, resulting in an infinite linear-chain framework of (CuS2)∞. Two types of chain–chain interactions exist, leading to a three-dimensional structure; stacking of the planar thione between the nearest neighbours with distances of 3.219(1) and 3.206(1)A for 1 and 2, respectively; hydrogen bonding between the counter anion X and the NH parts of the thione bridges the two ligands, and the neighbouring chains are linked. The visible spectra of the solids exhibited are different from those in solution, and are characteristic of the former. Complex 3 crystallizes in space group P, with a= 13.524(3), b= 13.547(2), c= 8.2106(9)A, α= 99.18(1), β= 101.01(1), γ= 118.26(1) and Z= 2. The copper core is a distorted octahedron, each copper having a trigonal geometry with two thionate sulfurs and a nitrogen donor from a µ3-thionate ligand. With the quinoline-2-thione ligand, the polymeric complex is preferred to the hexanuclear complex.

Hexanuclear polypyridine complexes containing different metals, bridging ligands and/or terminal ligands. Absorption spectra, electrochemical oxidation, luminescence properties and intercomponent energy transfer

Four novel hexanuclear complexes of general formula [(L) 2M(μ-BL)] 2M(μ-BL)M[(μ-BL)M(L) 2] 2 12+, where the metal ions M are Ru 2+ and/or Os 2+, the bridging ligands BL are 2,3-dpp and/or 2,5-dpp, and the terminal ligands L are bpy and/or biq, have been investigated (dpp  bis(2-pyridyl)pyrazine; bpy  2,2′-bipyridine; biq 2,2′-biquinoline). These polymetallic complexes can be considered as supramolecular species made of six distinct metal-containing units. They display very intense ligand centered absorption bands in the UV region (ϵ max in the order of 2.5×10 5 M −1 cm −1) and broad and intense bands in the visible region (ϵ max in the order of 5×10 4 M −1 cm −1). On electrochemical oxidation, the metal centers are oxidized at the same or different potentials depending on the nature of the metal ions (Ru 2+ or Os 2+) and on their positions (inner or outer) in the supramolecular structure. For all the novel compounds, luminescence can be observed in the red or near-IR spectral region. The luminescence properties, which are characteristic of specific metal-containing units, show that exoergonic electronic energy transfer between adjacent units is 100% efficient, whereas it is much lower when higher energy units are interposed. Various energy migration patterns can be obtained by placing different units in suitable sites of the supramolecular array.

High Mass Resolution Plasma Desorption and Secondary Ion Mass Spectrometry of Neutral Nickel Thiolate Complexes. Crystal Structure of [Ni6(SC3H7)12

The use of mass spectrometry for the analysis of transition metal complexes is demonstrated by combined high resolution Plasma Desorption Mass Spectrometry (PDMS) and Secondary Ion Mass Spectrometry (SIMS) investigations of the neutral nickel thiolate complexes [Ni4(SC3H7)8] (1), [Ni4(SC6H11)8] (2), [Ni8(SCH2COOEt)16] (3) and [Ni6(SC3H7)12] (4). The positive spectra are dominated by three kinds of SI-species: (a) molecular ions, (b) fragment ions and (c) molecular ions with one or more substrate atoms attached. The negative spectra show mainly nickel sulfur cluster ions of the composition (NixSy)-. In contrast to many Fast Atom Bombardment (FAB) spectra of neutral metal complexes, SIMS and PDMS spectra provide molecular weight as well as fragment ion information. Both techniques are most powerful tools for the investigation of coordination compounds because the samples are easy to prepare and the spectra are independent of matrix conditions. Additionally crystallographic studies have been carried out for 4. The hexanuclear complex 4 with square planar Ni-S coordination sites crystallizes in the trigonal space group R 3̅ with Z = 3 and α = 18.537(5), c = 13.966(3) Å.

Reactions of Tungsten Propargyl and Allenyl Complexes with Hydrido Triosmium Cluster: Molecular and Crystal Structure of Cp(CO)2[P(OMe)3]W(μ, η1, η2-CH2CH=CH)OS3(CO)10H and H2(CH2CH = CH)2Os6(CO)20

Reactions of H2Os3(CO)10, 3, with the monophosphite-substituted and non-substituted tungsten propargyl and allenyl carbonyl complexes Cp(CO)2LWCH2C≡CH (1a, L = CO; 1b, L = P(OMe)3) and Cp(CO)2LWCH = C = CH2 (2a, L = CO; 2b, L = P(OMe)3) were investigated. In the reaction of 1b with 3, a tetranuclear complex 4b is obtained. The molecules of 4b crystallize as Cp(CO)2[P(OMe)3]W(μ, η1, η2-CH2CH=CH)(μ-H)Os3(CO)l0 in space group PI with a = 9.490 (4), b = 13.072 (7), c = 13.770 (9) A, α = 91.89 (5), β = 106.71 (5), γ = 104.07(4)°, V = 1577(2) A3, Z = 2. In the reaction of 2a with 3, from the reaction mixture exposed to air followed by workup using silica-gel packed column chromatography, a complex consisting of two triosmium clusters bridged by a hexadiene ligand from the coupling of allenyl ligand was obtained. The molecules of the hexanuclear complex crystallize as [CH2CH = CH)2(μH)2OS6(CO)20in space group P21/c with a = 14.448 (7), b = 13.689 (4), c = 19.224 (4) A, β = 107.14(3)°, V = 3633 (2) A Z = 4.

Electrochemistry of [M 6(CO) 15] 2− anionic clusters (M = Co and Ir). Preparation and chemical characterization of [Ir 6(CO) 14(NCO)] − and of the radical anion [Ir 6(CO) 15] −. Proposed mechanism of formation of the hexanuclear substituted cluster [Ir 6(CO) 15Cl] −

Electrochemical studies performed on [Ir 6(CO) 15] 2− show that the dianion undergoes stepwise oxidation to the congeners [Ir 6(CO) 15] n ( n = −1 or 0); only the monoanion is notably long-lived. By contrast the electrochemical oxidation of [Co 6(CO) 15] 2− shows that both the corresponding monoanion and neutral clusters are transient species. Information gained on the oxidation of [Ir 6(CO) 15] 2− in the presence of halide ions has enabled establishment of the mechanism of formation of the anion [Ir 6(CO) 15Cl] −, previously characterized by an X-ray study. This process of oxidation of [Ir 6(CO) 15] 2− can be also initiated by treating the hexanuclear complex with chemical oxidants such as [Fe(C 5H 5) 2] + and FeCl 3. The characterization of [N(PPh 3) 2][Ir 6(CO) 14(NCO)], obtained by chemical oxidation of [N(PPh 3) 2] 2[Ir 6(CO) 15 in the presence of [N(PPh 3) 2]N 3, is also reported.

Availability of well‐defined iron colloids to the marine diatom Thalassiosira weissflogii

Three different types of iron oxo‐hydroxo colloids with well‐defined sizes and chemistries have been synthesized by hydrolysis of Fe(III) in acidic and alkaline medium as well as by oxidative hydrolysis of Fe(II), resulting in solutions of β‐FeOOH (30 nm), a hexanuclear complex (HN; 2 nm), and a polynuclear oxidation product (OP; 3 nm). These colloids were tested for their availability to the coastal diatom Thalassiosira weissflogii. Iron‐limited cells were grown in synthetic seawater containing 0–0.5 µM of total iron in colloidal form as the only iron source. We found no evidence of direct uptake of colloids by the algae. The β‐FeOOH colloids, which dissolve exceedingly slowly in the light or in the dark, did not support diatom growth. In contrast, maximal growth rates and cell yields were observed in the presence of either 50 nM OP or HN. Photoreduction accounted for the availability of HN. In the case of OP, thermal (dark) dissolution of the colloid appears sufficient to satisfy the iron requirement of the diatom.

Polynuclear platinum–silver, –copper, and –gold acetylide complexes. Molecular structure of [Pt2Ag4(CCBut)8

Hexanuclear complexes [Pt2Ag4(CCR)8] [R = Ph (1) or But (2)] have been obtained by treating [PtCl2(tht)2] (tht = tetrahydrothiophene) with [Ag(CCR)]n(Pt/Ag 1 : 4). The complexes [Pt2M4(CCR)8] [M = Cu, R = Ph (3) or But (4); M = Au, R = But (5)] were obtained from [Pt2Ag4(CCR)8] with CuCl or [AuCl(tht)] respectively. Alternatively, the reactions between [NBu4]2[Pt(CCR)4] and AgClO4, CuCl–NaClO4, or [AuCl(tht)]–NaClO4 yield respectively complexes (1)–(5). The molecular structure of [Pt2Ag4(CCBut)8] has been determined by an X-ray diffraction study: monoclinic, space group C2 with a = 37.062(7), b = 12.0223(16), c = 20.459(3) A, β = 107.485(15)°, Z = 6, R 0.0416, R′ 0.0465 for 5 613 reflections with F > 6σ(F). The six metal atoms are arranged in a slightly irregular octahedron with the platinum atoms mutually trans and the silver atoms in the equatorial plane, with Pt ⋯ Ag and Ag ⋯ Ag distances longer than 3.0 A. Each platinum atom is in an almost square-planar environment formed by four CCBut ligands. Each acetylenic fragment also forms an asymmetric π interaction with one silver atom of the equatorial positions so that each silver atom is bonded to two acetylenic fragments, of two different Pt(CCBut), moieties. These moieties of each [Pt2Ag4(CCBut)8] unit are staggered.

ChemInform Abstract: Preparation, Structure, and Magnetochemistry of Hexanuclear Manganese Oxide Complexes: Chemically and Thermally Induced Aggregation of Mn3O(O2CPh)6(py)2(H2O) Forming Products Containing the (Mn6O2)10+ Core.

AbstractA variety of synthetic procedures are described which convert the trinuclear title complex into the hexanuclear complexes (I).

A Novel Type of Anionic Cluster Containing a Pt4Ag2 Core

The anion 1, X = Cl, is a hexanuclear complex with an unusual structure. The R2Pt(μCl)2PtR2 groups (R  C6C15) are linked to the two Ag atoms through Pt → Ag donor bonds. Cl atoms of the C6C15 ligands and possibly of the μ-Cl bridges also transfer electron density to the Ag atoms. Compound 1, X = Br, was also synthesized.

Preparation, structure, and magnetochemistry of hexanuclear manganese oxide complexes: chemically and thermally induced aggregation of aquahexakis(benzoato)oxobis(pyridine)trimanganese forming products containing the [Mn6O2]10+ core

A variety of synthetic procedures are described that convert the trinuclear complex Mn30(02CPh)6(py)2(H20) (1) into the hexanuclear complexes [Mn602(02CPh)lo(py)2(MecN)2].2MeCN (2) and [Mn602(02CPh)io(py)4].Et20 (3). With two exceptions, the procedures involve treatment of 1 with phenolic molecules (phenol, p-cresol, tyrosine, 2,2'-biphenol, 8-hydroxyquinoline) or the mononuclear Mn' complexes [Mn(bi~hen)~(biphenH)]~and [Mn(Br4biphen)2(02CPh)]2in MeCN and lead to high (50-75%) yields of complex 2. It is proposed that the mechanism involves reduction of the [Mn30l6+ unit of 1 to a [Mn30I5+ species, which spontaneously aggregates to 2 containing the [Mn602]10t core. This proposal is supported by the formation of 2 when 1 is reduced with the outer-sphere reductant sodium acenaphthylenide. Complex 3 is obtained in 34% yield when a PhCN solution of 1 is refluxed for 10 min. Complex 2 crystallizes in triclinic space group PT with, at -140 OC, a = 15.389 (4) A, b = 19.513 (6) A, c = 14.433 (4) A, a = 91.84 (1)O, (3 = 94.08 ( 1 ) O , y = 87.85 (l)', and Z = 2. The structure was solved and refined by using 5999 unique reflections with F > 3.0u(F). Complex 3 crystallizes in triclinic space group P i with, at -160 C, a = 24.394 (16) A, (3 = 19.876 (11) A, c = 19.245 (12) A, CY = 89.71 (3)O, (3 = 105.43 (3)O, y = 79.89 (3)O, and Z = 2. The structure was solved and refined by using 6000 unique reflections with F > 3.0u(F). Final values of discrepancy indices R (R , ) for 2 and 3 are 7.82 (7.17) and 7.51% (7.63%), respectively. Complex 2 contains a [Mn602],io+ core that can be conveniently described as two edge-sharing Mn4 tetrahedra at the center of each of which is a p4-02ion. Peripheral ligation to the octahedrally coordinated Mn centers is provided by ten bridging benzoate, two terminal py, and two terminal MeCN groups. The complex is mixed valence (Mn4Mn11'2), and the Mn' centers are assigned as the two central metal ions bridged by two 02ions. Complex 3 contains two independent [M~I ,O , ] '~ complexes in the asymmetric unit, each of which is essentially identical with that in complex 2, except that the terminal ligands are all py. The results of solid-state magnetic susceptibility studies on complex 2 in the temperature range 2.95-300 K are described. With use of the idealized symmetry of two edge-sharing tetrahedra (D2h), the derivation by the Kambe vector-coupling method of a theoretical model to account for the intramolecular exchange interactions is described. Least-squares fitting of the susceptibility versus temperature data to the model yields the parameters J, = -42.0 cm-I, J2 = -0.8 cm-I, J3 = -2.4 cm-l, and g = 1.90, where the J values refer to the Mn'-Mn', Mn-Mn', and Mn-Mn interactions, respectively. These exchange parameters give an ST = 0 ground state with two degenerate ST = 1 states at 4 cm-I and degenerate ST = 0, 1, 2 states at 9 cm-' higher in energy. The magnitudes and signs of the exchange parameters are compared with those reported for other oxo-bridged Mn complexes. Complexes 2 and 3 join a small but growing number of high-nuclearity Mn aggregates, and the prospective and potential procedures that could be employed for the synthesis of higher nuclearity Mn aggregates that might display molecular ferromagnetism are discussed.

ChemInform Abstract: Heterobimetallic Clusters Derived from (MS4)2‐ (M: Mo or W): Synthesis and Structural Characterization of (NMe4)4((CuCl)5Cl2WS4), a Double Cubane‐Like Complex.

AbstractThe hexanuclear complex anion in (III), obtained by the procedure outlined in the scheme, is a new example for discrete copper tetrathiometalate clusters.

Bimetallic hexanuclear compounds containing unusual copper-lanthanide arrays: the crystal structures of Cu 4Ln 2L 8(LH) 4(OH) 2(NO 3) 4(H 2O) 2 (Ln  Dy or Gd; LH  2-(1H)-Pyridone, C 5H 5NO)

Reaction of copper hydroxide, 2-(1H)-pyridone ( LH), and dysprosium (or gadolinium) nitrate in methanol results in the formation of the unusual hexanuclear complexes, Cu 4Ln 2L 8(LH) 4(OH) 2(NO 3) 4(H 2O) 2 [Ln  Dy( 1) and Gd( 2)], which have been characterized by X-ray diffraction. The compounds are isostructural and in each case four copper and two lanthanide ions are bridged by trinucleating 2-pyridone anions to form an essentially octahedral Cu 4Ln 2 core. The lanthanide atoms are each nine-coordinate and the copper atoms five-coordinate. The core is surrounded by an exterior of largely hydrophobic ligand units.

Structural chemistry of titanium and aluminium bimetallic hydride complexes: VIII. Crystal and molecular structures of the complex (η 5-C 5H 5) 2Ti(η 2-H) 2Al(CH 3)(μ 2-H) 2Ti(η 5-C 5H 5) 2, an effective catalyst for olefin hydrogenation, and its decomposition product, [(η 5-C 5H 5) 2Ti(η 2-H) 2Al(η 2-H)-(η 1:η 5-C 5H 4) Ti(η 5-C 5H 5)(μ 2-H)] 2 ·

Reactions of (Cp 2Ti) 2AlH 4Cl and (Cp 2Ti) 2AlH 4BH 4 (Cp = η 5-C 5H 5) with LiCH 3 and LiAl(CH 3) 4 in ether or in an ether/benzene mixture yield a trinuclear complex Cp 2Ti(μ 2-H) 2Al(CH 3)(μ 2-H) 2TiCp 2, which crystallizes in a rhombic lattice with unit cell parameters a 8.405(1), b 21.349(3), c 22.337(3) Å, space group F2dd, Z = 8. The compound is unstable and decomposes in solution to give a new modification of a hexanuclear complex [Cp 2Ti(μ 2-H) 2Al(μ 2-H)(η 1 : η 5-C 5H 4)TiCp(μ 2-H)] 2 with unit cell parameters a 11.354(2), b 23.360(3), c 16.062(3) Å, γ 94.07(3)°, space group P2 1/ n, Z = 4. The instability of (Cp 2Ti) 2AlH 4Me is accounted for by an increase in the electron density on metal atom nuclei on coordination of the methyl group. For the same reason elevated catalytic activity of this compound in the reactions of hexene-1, homogeneoys hydrogenation (180 mol H 2/g-atom Ti min) and isomerization (11.8 mol C 6H 12/g-atom Ti min) is observed.

Stepwise construction of [Os6(CO)18(µ6-P)]–, a hexanuclear osmium cluster monoanion with trigonal-prismatic co-ordination for phosphorus: X-ray crystal structures of [Os6(µ-H)2(CO)20(MeCN)(µ3-PH)] and [PPh3Me][Os6(CO)18(µ6-P)

Treatment of the labile cluster [Os3(CO)11(MeCN)] with PH3 affords the substituted product [Os3(CO)11(PH3)](1) in high yield. Subsequent reaction of (1) with Na2CO3 in MeOH, followed by acidification, gives the hydrido phosphido cluster [Os3(µ-H)(CO)10(µ-PH2)](2). When (2) is heated to 45–60 °C in the presence of [Os3(CO)11(MeCN)] a hexanuclear complex with the formulation [Os6(µ-H)2(CO)21(µ3-PH)](3) is obtained. If this reaction is repeated using [Os3(CO)10(MeCN)2] instead of [Os3(CO)11(MeCN)], an acetonitrile-containing product, [Os6(µ-H)2(CO)20(MeCN)(µ3-PH)](4), is obtained. An X-ray analysis of (4) shows that two Os3 triangular units are linked by a µ3-phosphinidene ligand, which symmetrically bridges an Os–Os edge of one triangle and is terminally co-ordinated to one Os atom of the second triangle. When (3) is treated with a weak base, such as [N(PPh3)2]Cl or [PPh3Me] Br, deprotonation to the corresponding cluster monoanion [Os6(µ-H)(CO)21(µ3-PH)]–(5) occurs. Treatment of (5) with a weak acid regenerates (3) in quantitative yield. Thermolysis of (3) leads to a closing up of the metal framework, affording the cluster [Os6(µ-H)(CO)18(µ6-P)], which readily deprotonates to give the anion [Os6(CO)18(µ6-P)]–(7) in the presence of [N(PPh3)2] Cl or [PPh3Me]Br. The same anion (7) may also be obtained by direct thermolysis of (5). An X-ray analysis of the [PPh3Me]+ salt of (7) confirms that the phosphorus occupies an interstitial site in a trigonal-prismatic hexaosmium framework, and co-ordinates to all six metal atoms with an average Os–P distance of 2.31 (1)A. Proton and 31P n.m.r. data on all the new clusters are presented, and the position of the phosphorus resonance in the 31P n.m.r. spectrum is related to the changes in the environment of the phosphorus atom.

Notes. Heterobimetallic clusters derived from [MS4]2–(M = Mo or W): synthesis and structural characterization of [NMe4]4[(CuCl)5Cl2WS4], a double cubane-like complex

Reaction of [NMe4]2[MS4](M = Mo or W) with CuCl (1:3.5) in CH3CN produces a hexanuclear complex anion [(CuCl)5Cl2MS4]4–. Crystals of [NMe4]4[(CuCl)5Cl2WS4] are monoclinic, space group C2/c with cell dimensions a= 21.610(4), b= 9.340(2), c= 19.570(5), β= 92.84(2)°, and Z= 4. Least-squares refinement based on 2 708 reflections with I 3σ(I) converged at R= 0.032. The anion has crystallographically imposed C2 symmetry. The crystal structure determination shows that five of the six edges of the [WS4]2– tetrahedron are co-ordinated by CuCl units forming an open double cubane-like structure; the cubic geometry is achieved by chlorine atoms.

Infrared spectra of catalysts and adsorbed molecules Communication 36. Formation of cobalt carbonyl catalysts on various mineral supports

1. A study by infrared spectroscopy of the adsorption of dicobalt octacarbonyl on the surface of silica gel, aluminum and magnesium oxides, silicalite, and zeolites NaY and HY has shown that a series of adsorption compositions are formed in which an oxygen atom of a carbonyl bridging group and a cobalt atom of the metal carbonyl participate. 2. Dicobalt octacarbonyl is decarbonylated on the surface of mineral carriers with the formation of di-, tetra-, and hexanuclear cobalt complexes with simultaneous ligand exchange-with fragments of the surface; ligand exchange depends on the acid-base properties of the surface.

ChemInform Abstract: Preparation and Structural Characterization of a Novel Hexanuclear Complex of Platinum(II) with 2‐Aminoethanethiolate.

Chemischer InformationsdienstVolume 17, Issue 21 Organoelement Compounds ChemInform Abstract: Preparation and Structural Characterization of a Novel Hexanuclear Complex of Platinum(II) with 2-Aminoethanethiolate. D. GIBSON, D. GIBSONSearch for more papers by this authorS. J. LIPPARD, S. J. LIPPARDSearch for more papers by this author D. GIBSON, D. GIBSONSearch for more papers by this authorS. J. LIPPARD, S. J. LIPPARDSearch for more papers by this author First published: May 27, 1986 https://doi.org/10.1002/chin.198621285AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume17, Issue21May 27, 1986 RelatedInformation

Preparation and structural characterization of a novel hexanuclear complex of platinum(II) with 2-aminoethanethiolate

Preparation and structural characterization of a novel hexanuclear complex of platinum(II) with 2-aminoethanethiolate