简介：Polyolefinsthatbearachiralsidechain(typicallyanisobutylgroup)experienceaso-calledmacromolecularamplificationofchirality:thechiralside-chaininducesaslightpreferenceforeithertgortg-mainchainconformation.Thisslightconformationalbiasisamplifiedcooperativelyalongthechain,andresultsinpreferredchiralityofthemainchainhelicalconformations.Asaresult,thesepolymersdisplayaliquid-crystal(LC)phasebothinsolutionand,inthemeltasatransientphaseonthewaytocrystallization.Theexistenceoftwoprocesses(melt-LCandLC-crystaltransitions)resultsinunconventionalbehaviorsthatwerefirstanalyzedbyPinoandcollaboratorsbackin1975.Thesepolymersalsoofferameanstotestthestructuralconsequencesofrecentlyintroducedcrystallizationschemes.Theseschemespostulatetheformationofatransientliquid-crystalphaseasageneralschemeforpolymercrystallization.
简介：Dithia-monoaza18-Crown-6anditsimmobilizationproduct,silica-bound1,7-dithia-4-aza-10,13,16-trioxa-cyclooctadecaneviaaspacerofthreecarbonatoms,anditsplatinumcomplexhavebeensynthesized.Itisfoundthattheplatinumcomplexisanefficienthydrosilylationcatalystforolefins.TheXPSdataoftheplatinumcomplexarereported.
简介：TheL-proline-functionalizedpolystyrenewith1-methyldecylenespacerwassynthesizedfrom2%divinylbenzene-crosslinkedpolystyrenegelvia10-bromo-1-methyldecylpolystyreneintermediate.Aftercomplexedwithcopper(Ⅱ）ion,thepolymerwithL-prolineligandwasusedasthechiralstationaryphase(CSP)forligandexchangechromatographyofaminoacidracemates.TheresultsshowedthattheCSPpossessedpowerfulenantioselectivityandallracematesofthefifteentriedaminoacidswerecompletelyseparated.
简介：Thestructureofpolyimidefrom1,4-bis(3’,4’-dicarboxyphenoxy)benzeneand4,4’-oxydianilinefilmspecimensbeforeandafterhotstretchinghasbeeninvestigatedbyWAXD,DSCandFTIR.AsevidencedbyboththeWAXDandDSCresults,itcouldbebelievedthatstraininducedcrystallizationdidtakeplaceafterhotstretching.Meanwhile,shiftingpositionandsplittingofsomebandpeaksexistedontheFTIRspectrogramswereexplainedintermsoftheclosepackingofchainsandthechangesofinter-molecularcharge-transferinteractionbetweenimidegroupsandaromaticgroupsuponcrystallization.
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![SYNTHESIS OF POLY{（p—PHENYLENEVINYLENE）—alt—p,m—[2—PHENYL—5—（p—PHENYLENEVINYLENE）—<b style='color:red'>1</b>,3,4—OXADIAZOLYL]} WITH DEFINED CONJUGATION LENGTH AND IMPROMVED SOLUBILITY](/image/thesis4 "SYNTHESIS OF POLY{（p—PHENYLENEVINYLENE）—alt—p,m—[2—PHENYL—5—（p—PHENYLENEVINYLENE）—<b style='color:red'>1</b>,3,4—OXADIAZOLYL]} WITH DEFINED CONJUGATION LENGTH AND IMPROMVED SOLUBILITY")