1、Polyoxomolybdates and Their Applications In Catalytic OxidationPolyoxometalates or POMPolyoxometalatesHeteropoly Acids(HPA)(1)Heteropolyanions(2)Isopolyanions(3)多聚大分子氧氧化钼钼POM clusters(4)Organic Inorganic Hybrid POMPoly Molybdenum Oxides sturcturesynthesisOrganic Inorganic Hybrid polyMoOXApplications
2、 in catalytic oxidationPolyoxomolybdatesB,Si,Ge,P,As,SNa2MoO4Or(CuSO4)有机胺/模版剂H2O120-260 0CsynthesisPHViolaine Coue etal.,Inorg.Chem.46(2007)2824(i)concentration/type of metaloxide anion(ii)pH and type of acid (iii)heteroatom concentration,(iv)additional ligands (v)Reducing agent(vi)temperature and s
3、olvent.structurePrimary structure Mo6O19Mo3O13S2Mo5O23Mo4O13MoO4MoO6MoO5NMoO4N2Mo2O7EdgeCornerFace-sharingMoXOY(X8)POM-based Molecular Hybrids(a)Lindqvist anions,(b)Keggin anions(c)monosubstituted Keggin anions(d)Dawson-Wells anion:P2Mo18O626-(e)the polyoxometalateMo12O404-Mo6O194-D.Hagrman et al.In
4、organica Chimica Acta 300302(2000)212Mo 16 Mo 1813 A 11 A 6.6A.1Mo12+2Mo2.H2MoV 4MoVI 12O5210-D.L.Long,etal.,Angew.Chem.,Int.Ed.,2003,42,4180.Mo 183663Dawson-Wells AnionsSO4-based Dawson clustersa-Mo18O54(SO3)24-b-Mo18O54(SO3)24-X.M.Zhang ETAL.,Chem.Commun.,2004,2046.D.L.Long etal.,Angew.Chem.,Int.E
5、d.,2004,43,1817.Mo18O54(SO4)26-basket-shaped skeleton4554P6Mo18O7311-Mo 128,Mo 256 Mo 154 Mo248Muller and Serain,Acc.Chem.Res.2000,33,2big-wheelMo 368Achim Muller etal.,Angew.Chem.Int.Ed.2002,41,1162Achim Muller etal.,Angew.Chem.Int.Ed.2005,44,7757macromoleculebis(ethylenedithio)tetrathiafulvalene E
6、TTTF7Mo8O26ETET11Mo18O62Dawson-Wells Anions(TTF)tetrathiafulvalene,TTFTTF2(MoO6O19)Lindqvist anionsTTF6(Et4N)XMoO12O40Keggin anionsOrganic Inorganic Hybrid polyoxomolybdatesOrganoammonium-Molybdenum Oxide Pamela J.Jon Zubieta etal.Chem.Commun.,1997 321(4,4-H2bpy)Mo7O22H2OMoO3(pyridine)Molybdenum Oxi
7、de Phases ContainingOrganodiamine-Ligated HeterometalsCuD.Hagrman,J.Zubieta etal.,Chem.Commun.1998,1283.Molybdenum Oxide arraysD.Hagrman,J.Zubieta etal.,Chem.Mater.1998,10,3294.Applications in catalysisPOMsHeteropoly Acids(HPA)OxidationLiquid-Phase BiphasicHeterogeneousHydration of Olefins:RCH=CH2+H
8、2O+RCH(OH)CH3 Esterification(MTBE)(CH3)2C=CH2+CH3OH+CH3OC(CH3)3 CondensationOxidationIvan V.Kozhevnikov.Chem.Rev.98(1998)171Journal of Molecular Catalysis A:Chemical 243(2006)244Oxidation of alcohols to aldehydes with H2O2Oxidation with O2Ronny Neumann and Mazal Dahan,Polyhedron17(1998)3557Oxygen ta
9、nsfer from sulfoxides by POMoAlexander M.etal.J.AM.CHEM.SOC.124(2002)4198PM12O403-Q3=(C4H9N+)3Q3PMo()12O40sulfoxidesOxidehydrogenation with tert-ButylhydroperoxideAlexander M.etal.J.Am.Chem.Soc.2001,123,6437-6438小结 多聚钼酸盐与氧化钼是以MoOX为核心的大分子共聚物.共聚物中钼原子的数量可以从几个到几百个;而多聚氧化钼的结构可以从简单的多面体到大轮(big wheel)乃至三维方向上的球体.多聚氧化钼通过有机无机杂化可以实现一维链状,二维网状,三维网络(network)状的空间排布.多聚钼酸盐与氧化钼除了具有多聚金属氧化物的杂多酸催化特性外,还有着较好的催化氧化性能.当采用不同的氧化剂时,如H2O2,O2,sulfoxides,tert-Butylhydroperoxide,可通过不同的氧化机理和机理间的竞争实现不同氧化产物的生成.
