METALPHOSPHONATEMONOLAYERS: DEVELOPMENTOFA PHOSPHORYLATEDTEMPLATEUSINGORGANIC SELFASSEMBLY By MARGARETLEIGHCREWS ATHESISPRESENTEDTOTHEGRADUATESCHOOL OFTHEUNIVERSITYOFFLORIDAINPARTIALFULFILLMENT OFTHEREQUIREMENTSFORTHEDEGREEOF MASTEROFSCIENCE UNIVERSITYOFFLORIDA 1992 ACKNOWLEDGEMENTS IwouldliketoacknowledgetheUniversityofFlorida,theDivisionof SponsoredResearch,andtheDonorsofthePetroleumResearchFundadministeredby theAmericanChemicalSocietyforprovidingtheresourceswhichallowedmetostudy hereattheUniversityofFlorida. Iamalsoindebtedtomyresearchadvisor.Dr. DanielR.Talham,forhisguidanceandmanyeducationaldiscussions. IwouldliketothankthemembersoftheTalhamGroup,especiallymyfellow chartermembersJohnPikeandHoustonByrd,fortheirideasandencouragement JohnPikedeservesaveryspecialthankyouforperformingalloftheXPSanalyses. AlsodeservingofthanksaretheMajorAnalyticalInstrumentationCenterfor providingtheinstrumentfortheXPSanalyses,andDr.BowdenAndraka,who performedthetemperaturedependentmagneticmeasurements. Finally,Iwouldliketoacknowledgethreeveryimportantpeople. Myparents, SamandGinnyCrews,haveprovidedaquarterofacenturyoflove,guidance,and support,bothfinancialandmoral. Mysoon-to-behusband,SteveShowalter,deserves specialmentionforhisconstantencouragementandsupport,andforteachingme almosteverythingIknowaboutcomputers. 11 TABLEOFCONTENTS ACKNOWLEDGEMENTS ii LISTOFTABLES iv LISTOFFIGURES v ABSTRACT vii INTRODUCTION 1 Objective 1 Background: SAMonolayers 3 EXPERIMENTAL 16 General 16 CompoundSyntheses 17 MonolayerFormationandConversion 22 RESULTSANDDISCUSSION 25 BulkManganesePhosphonates 25 FormationofSAMonolayers 28 MonolayerCharacterization: ATR-FTIRandESCA 36 CONCLUSIONS 55 REFERENCELIST 5g BIOGRAPHICALSKETCH 61 in LISTOFTABLES Table1 ElementalCompositionDeterminedbyESCA 52 Table2 RelativeAmountsofZrandPDeterminedbyESCA 53 IV LISTOFFIGURES Figure1 Structureofalayeredorganic-inorganicsolid 2 Figure2 Synthesisofaninorganicmonolayeratanorganictemplate 4 Figure3 FormationofSelfAssembledmonolayers 6 Figure4 Mallouk’stechniqueforthesynthesisofzirconium phosphonatemultilayers 10 Figure5 DiagramoftheopticalpathforATR-FTIR 15 Figure6 Temperaturedependenceofthemagneticsusceptibilityof manganesephenylphosphonate 27 Figure7 Firstsyntheticschemeforaphosphorylatedsurface 29 Figure8 ProtonNMRofH2C=CH(CH2)9P(0)(0Et)2 31 Figure9 Secondsyntheticschemeforaphosphorylatedsurface 33 Figure10 Bindingofinorganicionsandcappinglayeratorganictemplate . 35 Figure11 ATRspectrumofCljSKCH^pCHj 37 Figure12 ATRspectrumof(EtOXSXCH^jPCOXOEtX 39 Figure13 ATRspectrumofCljSiCCH^Br 41 Figure14 ATRspectrumof-(CH2)16P(0)(0Et)2 42 Figure15 ATRspectrumof-(CH2)16P03H2 44 Figure16 IRspectrumofHjOjPCCH^joPOjHj 45 Figure17 ATRspectrumofzirconatedandcappedmonolayer 46 v Figure18 ESCAspectrumforthebromidemonolayer 48 Figure19 ESCAspectrumofthephosphonatemonolayer 49 Figure20 ESCAspectrumofthephosphonicacidtemplateafterbindingof zirconium 50 Figure21 ESCAspectrumofthecappedzirconiumlayer 51 vi AbstractofThesisPresentedtotheGraduateSchool oftheUniversityofFloridainPartialFulfillmentofthe RequirementsfortheDegreeofMasterofScience METALPHOSPHONATEMONOLAYERS: DEVELOPMENTOFA PHOSPHORYLATEDTEMPLATEUSINGORGANIC SELFASSEMBLY By MargaretLeighCrews August1992 Chairperson: Dr.DanielR.Talham MajorDepartment: DepartmentofChemistry Layeredinorganicsolidshavebeenusedasmodelsforthestudyoftwo dimensionalmagnetism. Inthestudyofthesequasi-twodimensionalsystems,itis assumedthattheintralayerinteractionsareinsignificantrelativetotheinteractions betweenmetalcenterswithinasinglelayer. Ifasinglelayerofoneoftheselayered solidscouldbeisolatedforthestudyoflowdimensionalmagnetism,theneedtomake suchanassumptioncouldbeeliminated. Theresearchpresentedinthisthesiscoverstheprogresswhichhasbeenmade towardthepreparationofamagneticmonolayerbasedonlayeredmetalphosphonates. Theresultsincludethestudyofthemagneticbehaviorofthelayeredsolidmanganese phenylphosphonate,Mn^PC^jHjO,andthepreparationofaphosphonicacid Vll terminatedorganicselfassemblymonolayerwhichcanbeusedasatemplateforthe constructionofinorganicmonolayers. vm INTRODUCTION Objective Thegoalofthisresearchistosynthesizeamonolayeranalogofalayered inorganicsolidforthestudyofmagnetismintwodimensions. Thequestionof whetherornotatrulytwo-dimensionalsystemcanundergoatransitiontolongrange magneticorderisafundamentalone1. Layeredinorganic-organicsolids,whichhave thegeneralstructureshowninFigure1,havebeenusedasmodelsforthestudyof two-dimensionalmagnetism. Inthestudyofthesequasitwo-dimensionalsolids,itis assumedthattheintralayerinteractionsareinsignificantrelativetotheinteractions betweenmetalcenterswithinasinglelayer. Theneedtomakesuchanassumption couldbeeliminatedbystudyingatrueinorganicmonolayer. Ourapproachtothesynthesisofamagneticmonolayeristoutilizean appropriatelyfunctionalizedorganictemplatetobindthemetalcentersofinterest. Transitionmetalionsandcomplexeshavebeenboundatthefunctionalizedsurfacesof orientedorganicmonolayerspreparedbyeithertheLangmuir-Blodgetttechniqueor theSelfAssemblytechnique2,3. Byusinganinorganicsystemwhichnaturallyformsa layeredinorganic-organicsolid,itmaybepossibletoconstructaninorganicmonolayer inwhichthemetalionsarenotonlyboundtotheorganictemplate,butarealsobound toeachotherinamanneranalogoustotheinteractionfoundinthelatticeofthebulk 1 - ORGANICLAYER INORGANICLAYER Figure1 Structureofalayeredorganic-inorganicsolid