Highly symmetric organic ligand-capped Lindqvist structures derived from 3d-elements.

Interaction of M(acac)(2) with Ti(OEt)(4) associated with hydrolysis or thermolysis provides with high yields, through the decomposition of the initially formed M(2)Ti(2)(acac)(4)(OEt)(8), M = Ni (1), Co (2), poorly soluble Lindqvist-type products with the formula M(5)TiO(acac)(6)(OEt)(6), M = Ni (3), Co (4), Mg (5). The compounds 3-5 are isostructural and display a perfect statistical disorder between the OEt groups and 1/2 of the beta-diketonate, acac, ligand. The metal atoms constitute a regular octahedron, centered by the oxo-oxygen atom. There is only one symmetrically independent metal site, which imposes it to contain 1/6 of titanium and 5/6 of the divalent metal atom. The oxygen atoms on the surface of the octahedron are doubly bridging and are located above the twelve edges of the octahedron, as is usual for the Lindqvist-type structures. The coordination of the metal atoms is completed by a single terminal oxygen atom. The complexes 3-5 are volatile with decomposition, releasing only homometallic products into the gas phase in the case of 3 and 4, but with a considerable contribution of molecular evaporation in the case of 5. The intermediates 1 and 2 belong to the tetramolybdate, M(4)O(16), structure type. Highly soluble 1 and 2 can be considered as attractive molecular precursors for the incorporation of 3 and 4 into porous matrices for the preparation of combustion catalysts. Application of the same synthetic approach to n-propoxide complexes offers in a Co-Ti system a derivative with a different composition and resolved metal and ligand disorder, Co(4)Ti(2)O(acac)(4)(O(n)Pr)(10) (6), which, however, still follows the Lindquist type and displays high (tetragonal) symmetry for both the molecule and the crystal structure.

[1]  Achim Müller,et al.  Structure-related frustrated magnetism of nanosized polyoxometalates: aesthetics and properties in harmony. , 2010, Dalton transactions.

[2]  R. Errington,et al.  Extending the Lindqvist Family to Late 3d Transition Metals: A Rational Entry to CoW5 Hexametalate Chemistry , 2009 .

[3]  G. Seisenbaeva,et al.  Precursor and solvent effects in the nonhydrolytic synthesis of complex oxide nanoparticles for bioimaging applications by the ether elimination (Bradley) reaction. , 2009, Chemistry.

[4]  K. Wijayantha,et al.  Photooxidation of water by NiTiO3 deposited from single source precursor [Ni2Ti2(OEt)2(micro-OEt)6(acac)4] by AACVD. , 2009, Dalton transactions.

[5]  Lin Huang,et al.  Assembly of two novel Lindqvist polyoxoanion-templated coordination polymers with standard honeycomb cavities , 2009 .

[6]  Z. Su,et al.  Highly stable crystalline catalysts based on a microporous metal-organic framework and polyoxometalates. , 2009, Journal of the American Chemical Society.

[7]  Johann Spandl,et al.  Exchange Interactions and Electron Delocalization in the Mixed-Valence Cluster V4IVV2VO7(OC2H5)12 , 2008 .

[8]  Michael A. Rodriguez,et al.  Controlled Assembly of [Nb6–xWxO19](8–x)– (x = 0–4) Lindqvist Ions with (Amine)copper Complexes , 2008 .

[9]  Jingping Wang,et al.  A novel disubstituted Lindqvist-type polyoxomolybdate [Te2Mo4O19]6− supporting two organic vanadyl moieties: Synthesis, characterization, and crystal structure of {[V(2,2-bipy)2]2(4,4-bipy)[Te2Mo4O19]} , 2008 .

[10]  G. Seisenbaeva,et al.  Heteroleptic metal alkoxide "oxoclusters" as molecular models for the sol-gel synthesis of perovskite nanoparticles for bio-imaging applications. , 2008, Dalton transactions.

[11]  R. Errington,et al.  Non-aqueous synthetic methodology for TiW(5) polyoxometalates: protonolysis of [(MeO)TiW(5)O(18)](3-) with alcohols, water and phenols. , 2007, Dalton transactions.

[12]  Yuming Dong,et al.  A facile route to controlled synthesis of Co3O4 nanoparticles and their environmental catalytic properties , 2007 .

[13]  Michael A. Rodriguez,et al.  An aqueous route to [Ta6O19]8- and solid-state studies of isostructural niobium and tantalum oxide complexes. , 2007, Dalton transactions.

[14]  R. Errington,et al.  Synthesis and reactivity of the methoxozirconium pentatungstate (nBu4N)6[{(mu-MeO)ZrW5O18}2]: insights into proton-transfer reactions, solution dynamics, and assembly of {ZrW5O18}2- building blocks. , 2007, Journal of the American Chemical Society.

[15]  C. Hill.  Progress and challenges in polyoxometalate-based catalysis and catalytic materials chemistry , 2007 .

[16]  R. Thouvenot,et al.  Structural determination by X-Ray diffraction and 183W NMR spectroscopy of mono substituted hexatungstates [(n-C4H9)4N]3MW5O19 (M = Nb, V) , 2006 .

[17]  C. Zhong,et al.  Crystal structure and electrochemical behavior of a novel polyoxometalate [Ni(bpy)3]2[W4V2O19] with Lindqvist‐type structure , 2006 .

[18]  G. Seisenbaeva,et al.  New insight in the role of modifying ligands in the sol-gel processing of metal alkoxide precursors: A possibility to approach new classes of materials , 2006 .

[19]  M. Che,et al.  Zirconium-substituted isopolytungstates: structural models for zirconia-supported tungsten catalysts. , 2006, Inorganic chemistry.

[20]  Y. Wang,et al.  A kinetically controlled trans bifunctionalized organoimido derivative of the Lindqvist-type hexamolybdate: synthesis, spectroscopic characterization, and crystal structure of (n-Bu4N)2{trans-[Mo6O17(NAr)2]} (Ar = 2,6-dimethylphenyl). , 2005, Inorganic chemistry.

[21]  C. Daniel,et al.  Neutral and cationic V(IV)/V(V) mixed-valence alkoxo-polyoxovanadium clusters [V6O7(OR)12]n+ (R = -CH3, -C2H5): structural, cyclovoltammetric and IR-spectroscopic investigations on mixed valency in a hexanuclear core. , 2005, Journal of the American Chemical Society.

[22]  P. Kulesza,et al.  Network electrocatalytic films of conducting polymer-linked polyoxometallate-stabilized platinum nanoparticles , 2005 .

[23]  A. Orlandini,et al.  Structure and magnetism of a new hydrogen-bonded layered cobalt(II) network, constructed by the unprecedented carboxylate-phosphinate ligand [O2(C6H5)PCH2CO2]2-. , 2005, Inorganic chemistry.

[24]  R. Errington,et al.  Covalent immobilization of a TiW5 polyoxometalate on derivatized silicon surfaces. , 2005, Angewandte Chemie.

[25]  G. Seisenbaeva,et al.  Influence of heteroligands on the composition, structure and properties of homo- and heterometallic zirconium alkoxides. Decisive role of thermodynamic factors in their self-assembly , 2004 .

[26]  V. Kessler,et al.  Powders and dense thin films of late transition metal oxide nanocomposites from structurally characterized single-source precursors , 2004 .

[27]  G. Seisenbaeva,et al.  Molecular structure design approach to perspective single-source precursors of titanate materials. Synthesis, X-ray single crystal and mass-spectrometric study of M2Ti2(acac)4(OMe)8, M=Mg, Co , 2004 .

[28]  V. Kessler.  Molecular structure design and synthetic approaches to the heterometallic alkoxide complexes (soft chemistry approach to inorganic materials by the eyes of a crystallographer). , 2003, Chemical communications.

[29]  V. Kessler,et al.  Application of MII2MV2(acac)2(OMe)12 Derivatives in Sol-Gel Preparation of Oxide and Oxide Nanocomposite Materials for Catalysis , 2003 .

[30]  Jun Li.  Electronic Structures, (d-p)π Conjugation Effects, and Spectroscopic Properties of Polyoxometalates: M6O192− (M=Cr, Mo, W) , 2002 .

[31]  V. Kessler,et al.  Interaction of Co(acac)2 and Ta(OMe)5: isolation and single crystal study of the products. MII2MV2(acac)2(OMe)12, MII = Co, Ni, Zn or Mg and MV = Ta or Nb: A new class of heterometallic heteroleptic alkoxide complexes , 2001 .

[32]  G. Seisenbaeva,et al.  The mystery of VO(OEt)3 conversion on microhydrolysis disclosed: the X-ray single crystal study of V6O7(OEt)12 , 2000 .

[33]  M. Carducci,et al.  Direct hydrolytic route to molecular oxo-hydroxo lanthanide clusters. , 2000, Inorganic chemistry.

[34]  L. Hubert-Pfalzgraf,et al.  Chemical routes to barium-cerium oxides: the quest for mixed-metal precursors. Molecular structure of Ba4Ce2(μ6-O)(thd)4 (μ3-OPri)8(OPri)2 , 1998 .

[35]  Ulrich S. Schubert,et al.  Oxozirconium Methacrylate Clusters: Zr6(OH)4O4(OMc)12 and Zr4O2(OMc)12 (OMc = Methacrylate) , 1997 .

[36]  R. Errington,et al.  Alkoxide hydrolysis as a route to early transition-metal polyoxometalates: synthesis and crystal structures of heteronuclear hexametalate derivatives , 1996 .

[37]  Achim Müller,et al.  Polyoxometalates : from platonic solids to anti-retroviral activity , 1994 .

[38]  J. Galy,et al.  New precursors in the chemistry of IVB transition metal alkoxides II. Synthesis and molecular structure of Zr2Co4(μ6-O)(μ2-OC3H7)8(OC3H7)2(acetylacetone)4 , 1991 .

[39]  V. Kessler,et al.  Molybdenum and tungsten (VI) bimetallic alkoxides. Decomposition accompanied by dialkylether elimination , 1991 .

[40]  K. G. Caulton,et al.  Carbon-oxygen bond scission in heterometallic alkoxides: formation and structure of K4Zr2O(OCHMe2)10 , 1990 .

[41]  V. Kessler,et al.  Hydrolysis of molybdenum and tungsten alkoxides: sols, powders and films , 1990 .

[42]  J. Fuchs,et al.  Neubestimmung der Kristallstruktur von Tetrabutylammoniumhexawolframat , 1978 .

[43]  H. Allcock,et al.  Crystal and molecular structure of a new hexamolybdate-cyclophosphazene complex , 1973 .

[44]  D. C. Bradley,et al.  19. Niobium and tantalum mixed alkoxides , 1958 .