通过有机配体界定的锌的磷酸化合物拓扑结构(晶(8)

NoWelZincPhosphateTopologies

Figure5.(a)Asymmetricunitofthestructureofcompound5showingtheatomlabelingscheme.Thermalellipsoidsaredrawnat50%probability.(b)Packingdiagramofcompound5.

Theasymmetricunitin5containsonecrystallographicallyindependentzincatom,aphosphategroup,andanL4ligand,asillustratedinFigure5a.Thezincphosphateportionofthestructureisagaina4.82-sheetwithaherringbonepatternof8-ringssimilartothatobservedincompound4.In5,thesheetisdecoratedonbothsidesbythemonodentateL4ligand.Thus,thesheetsareneutralandheldtogetheronlybyvanderWaalsforcestoforma3Dstructure.ApackingdiagramisshowninFigure5b.Thenearestapproachbetweenanthracenehydrogenatomsfromadjacentsheetsis2.65Å,butthereisnoπoverlap.TheshortestH-Xcontactbetweenanthraceneringsassociatedwithasinglesheetis3.06Å(X

referstothecentroidofthebenzenering)withaC-H-Xangleof130.4°.Thisindicatesweakinteractionswithineachsheet.Thepackingofanthracenegroupsononesideofazincphosphatesheetmimicstheherringbonepatternof8-ringsinthe4.82-net.Thatis,thereisoneanthraceneringper8-ringoneachsideofthezincphosphateplaneandeachfillsthespaceabovean8-ringwiththelongaxisofanthraceneprojectedontothelongaxisofthe8-ring.Thezincatomswithinasheetarecoplanar,andthedistancebetweenthelayersis19.72Å.

StructureofCompound[Zn2(HPO4)2(C12H10N4)](6).Compound6isformedfromzincphosphateandtherigidbidentateligandL5.Theasymmetricunitofcompound6containsonecrystallographicallyindependentzincatom,aphosphategroup,andhalfofanL5ligand,asshowninFigure6a.EachzincatomistetrahedrallycoordinatedbythreephosphateoxygenatomsandanitrogenfromL5[(Zn1-O)av)1.942Å,(O-Zn1-O)av)111.9°,and(O-Zn1-N)av)106.8°].EachphosphategroupcoordinatestothreezincatomsthroughP-O-Znlinkages[(P-O-Zn)av)121.8°].

AsshowninFigure6b,theinorganiclayerin6iscomposedsolelyof6-ringstogivea63topology.The6-ringinzincphosphatesisknown,23specificallyinthesodalitestructure;however,theplanar6-ringpattern,asin6,hasnotbeenobservedpreviouslyforzincphosphates.Recently,Harrisonreportedathree-dimensionalzincphosphitestruc-ture,(C6N2H8)0.5 ZnHPO3,inwhichaninorganicsheetwiththe63topologyispillaredby1,4-diaminobenzene.6bIn6,theparallelzincphosphatesheetsarelinkedbyL5ligands.Theligandsonoppositesidesofthesheetsleansignificantlyfromtheperpendicular;themajoraxisoftheligandshasanangleofabout50°withrespecttothesheet.Thus,thepillarsleansignificantlytocompresstheinterlayerspacingto8.3Åinthe3Dstructure.ThepackingofthesheetsandtheL5pillarsisshowninFigure6c.Discussion

Ofthefiveligandsusedtopreparesixnewzincphosphatephasesinthisstudy,thetwowiththegreatestflexibility,L1andL2,pounds1and2formwithL1;compound3andthestructurallyuncharac-terizedphase7formwithL2.TheobservationofmixedproductswiththeseligandsisattributedtotheflexibilityandmultifunctionalityofL1andL2.

Compounds1and3containbothHPO42-andH2PO4-,whilecompounds2,4,5,and6containonlyHPO42-.Further,thestoichiometryof1and3requiresextraframeworkcationstobalancethenetanionicchargeoftheframeworks.DiprotonatedL1servestheroleofextraframeworkcationin1,andin3,twoimidazolegroupsofthetetradentateligandL2areprotonated.DihydrogenphosphateandsubstitutedimidazoleshavesimilarpKa’s.Thus,thesesystemsthat

(23)(a)Kongshaug,K.O.;Fjellvag,H.;Lillerud,K.P.SolidStateSci.

2000,2,569.(b)Rodgers,J.A.;Harrison,W.T.A.J.Mater.Chem.,2000,10,2853.(c)Feng,P.;Bu,X.;Stucky,G.D.Angew.Chem.,Int.Ed.Engl.1995,34,1745.(d)Jensen,T.R.;Norby,P.;Stein,P.C.;Bell,A.M.T.J.SolidStateChem.1995,117,

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