通过有机配体界定的锌的磷酸化合物拓扑结构(晶(6)

NoWelZincPhosphateTopologies

L1ligands[(Zn-O)av)1.944Åand(Zn-N)av)1.999Å];theotherzinciscoordinatedbythreeoxygensfromphosphategroups[(Zn-O-P)av)135.4°]andonenitrogenfromL1[(Zn-O)av)1.922Åand(Zn-N))2.029Å].ThetwophosphorusatomsareconnectedsuchthatP1islinkedtoZnbythreeP-O-ZnlinkagesandP2isconnectedtozincbytwoP-O-Znlinkages.ThelongestP-Obondlengthforthetwophosphorusgroupsis1.570(2)Åand1.589(2)Å,respectively,correspondingtothe-OHgroup.21Thus,eachphosphorusgroupisaHPO42-anion.Toconfirmtheassignment,thehydrogenatomsattachedtothephos-phorusgrouparelocatedintheresiduale-densitymapandrefinedindependently.Theresultingstoichiometry,Zn2-(HPO4)2,givesaneutralframework.

Theinorganicmotifin2consistsofaone-dimensional(1D)polymericzinc-oxygen-phosphatechainconstructedfromedge-sharing4-ringsand8-rings,asillustratedinFigure2b.Thestrictlyalternating4-ringand8-ringpatternappearsfrequentlyinzincphosphates/phosphites,especiallyin4.82-sheets.22However,isolated4.8-chainshavenotbeenprevi-ouslyreported.The4.8-chainscanformeitherbyjoining8-ringsinsuchawaytocreatethe4-ringorbyformingasimpleladderandcleavingtwooutofeveryfourrungsintheladder.

ThetwozincatomswithaZnO3Ncoordinationsetarecontainedwithinthe8-ringsand4-rings;thetwozincatomsthathaveaZnO2N2coordinationsetareonlyfoundinthe8-rings.In2,thechainstructuresareparallelandpropagatealongthe[100]direction,asshowninFigure2c.InFigure2d,each4.8-chainisshownconnectedto6neighboringchainsviaL1ligandstoforma3Dstructure.

CrystalStructureof[Zn3(HPO4)3(H2PO4)(C22H22N8)0.5-(C22H24N8)0.5](3)pound7givescrystalsofinsufficientqualityforadeterminationofthecompletestructure,whichappearstobea3Dhybridframework,andtherefinementisnotofahighenoughqualityforpublication.Acompletestructureofthecompounddesignatedas3wasdetermined.Theasymmetricunitof3containsthreecrystallographicallydistinctZnatomsandfourPatoms,asshowninFigure3a.EachzincatomistetrahedrallycoordinatedbythreephosphateoxygenatomsandoneimidazolenitrogenfromL1:(Zn1-O)av)1.946Å,(O-Zn1-O)av)109.4°,(O-Zn1-N)av)108.8°;(Zn2-O)av)1.935Å,(O-Zn2-O)av)109.9°,(O-Zn2-N)av)108.7°;(Zn3-O)av)1.941Å,(O-Zn3-O)av)111.7°,(O-Zn3-N)av)107.0°.Ofthefourphosphategroups,P1coordinatestotwozincatoms,P2andP3coordinatetothreezincatoms,andP4coordinatestoonezincatom.TheP-Odistances[(P1-O1))1.590(3),(P2-O5))1.564(3),(P3-O10))1.563(3),(P4-O13))1.576(3),and(P4-O16))

(21)Brown,I.D.;Aldermatt,D.ActaCrystallogr.1984,B41,244.

(22)(a)Gordon,L.E.;Harrison,W.T.A.ActaCrystallogr.2004,C60,

m637.(b)Harrison,W.T.A.Int.J.Inorg.Mater.2001,3,179.(c)Ayi,A.A.;Choudhury,A.;Natarajan,S.;Rao,C.N.R.J.Mater.Chem.2000,10,2606.(d)Zhang,D.;Shi,Z.;Dong,W.;Fu,W.;Wang,L.;Li,G.;Feng,S.J.SolidStateChem.2004,177,

343.

Figure3.(a)Crystalstructureofcompound3withatomlabelingscheme.Thermalellipsoidsaredrawnat50%probability.(b)Schematicdrawingofthe1Dchainin3.(c)2Dstructureofcompound3.

1.590(3)Å]indicatethattheterminaloxygens(O1,O5,O10,O13,andO16)are-OHgroups.21

AsshowninFigure3b,theinorganicstructureof3consistsofaone-dimensionalchainconstructedfromalternating4-ringsandtriplefused4-ringsthatareconnectedthroughonevertex.The4-ringsarecomposedofvertex-sharingZn3andP3tetrahedra,andthetetrahedralcoordinationenviron-mentofZn3iscompletedbytwoP3bridginggroups,anL2ligand(N5),andapendantP4group.Thetriplefused4-ringiscomposedofthreeedge-sharing4-ringsofZnO3N(Zn1andZn2)andHPO4(P1andP2)tetrahedra.The4-ringisawell-knownsecondarybuildingunit,andthetriplefused4-ringhasrecentlybeensuggestedasatertiarybuildingunit.10Thechainstructurecomposedofthestrictlyalternating4-ringandtriplefused4-ringisnewandmaybedescribedasarisingfromtheself-assemblyoftriple4-ringsand4-rings.Alternatively,itmaybeconsideredtobeafrustratedladderstructureinwhichthependantphosphategrouppreventstheformationoftheladdermotif.

Compound3containstwotypesofL2ligands:onecoordinatestofourzincatomsasatetradentatebridgingligand,andtheothercoordinatestotwozincatomsasabidentatebridgingligand,asseeninthepartialpackingdiagraminFigure3c.Thefragment,[Zn3(HPO4)3(H2PO4)]2,hasanetframeworkchargeof-2whichisbalancedbythediprotonationofthetwounligatedimidazolegroupsofthebidentatebridgingL2ligand.Toconfirmtheassignment,thehydrogenatomsattachedtothefreearms(N7andN7A)

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