路易斯碱低温碳化聚合物

.,.,能提供电子云的分子或原子团称为路易斯碱。路易斯碱即电子给予体，是在酸碱电子理论定义下的碱，指可以提供电子对的分子或离子。任何在键结轨道中有孤对电子的分子均为路易斯碱。此处碱的定义和阿累尼乌斯对碱的定义不同，因此路易斯碱溶在水中不一定会产生氢氧根离子。氢键X-HY中的电子给予体Y是路易斯碱。,路易斯碱,.,Poly(diiododiacetylene)(PIDA)isaconjugatedpolymercontaininganall-carbonbackboneandonlyiodineatomsubstituents.PIDAispreparedbytopochemicalpolymerizationofmonomerdiiodobutadiynewithinhostguestcocrystals.stableatroomtemperatureexplosiveunderexternalenergysuchasshockorpressure.,Poly(diiododiacetylene)(PIDA),.,thermalconditions,carbonizationofPIDAfibersstartsat120C,andcompletecarbonizationcanbeachievedbypyrolysisat900Cfor1h.irradiatedwitha532-nmRamanlaser,thePIDAfiberstransformirreversiblyatroomtemperaturetosp2-hybridizedcarbon.ThegeneralityofthisiodineeliminationfurthersuggeststhatreactionofPIDAwithLewisbasesdehalogenatesthepolymer,presentinganewmethodtopreparecarbonnanomaterialsatroomtemperatureunderverymildconditions.pyrrolidine,pyridine,andotheramines,canreactwithPIDAtoreleaseiodineandthuscarbonizethepolymeratroomtemperature.,Researchcourse,.,680nmandalonger-wavelengthabsorptionshoulderthatisassociatedwiththeggregationofthepolymerchains750nmdecreasesimmediatelyafterthebaseisadded,indicatingthatthepolymerstartstodeaggregate.pyrrolidinecausingafastercolortransitionthanpyridineortriethylamineatthesameconcentration.noapparentpeakabove450nm,.,fromametalliclustertodarkgray-blackmaterialmaintainsafibrousmorphologyafterreactionwiththeLewisbasemixingbulkPIDAwithneatpyrrolidineresultsinadark,opaquesuspensionwhichisdifficulttoseparate,.,最初实验已证明:依赖于离子反应而非极性机制，在甲烷等非极性溶剂中反应很慢或几乎不反应，在四氢呋喃或吡咯烷极性溶剂中反应，但是从极性溶剂中取出，反应不受到影响。更详细的机理还有待研究,.,热重量分析图。降低很平缓。在原始聚合物150度开始降低，550时还有18%残留。处理过后聚合物550C降低,44%残留.,.,PIDA拉曼峰971,1407,2074cm1.与吡咯烷反应后只有13601580，与碳纳米纤维石墨碳类似表明不定形由于与吡咯烷反应或反应不完全，碳化不充分,.,碳13核磁共振图谱表明这两种物质已有不同的结构和性能初始的sp2和sp在反应后都不在存在，被50150的宽峰代替处理过后的物质在高强度磁场中不在发生旋转，除非放在没有磁性的盐中。说明能产生涡电流，导电性得到大大增强。,.,量化分析碳化后产物的导电性，用交变电流进行测试。嘧啶处理过后是原来的10多倍，吡咯烷处理过后的是原来10000倍这与碳13MASNMR相符合.,.,LewisbasescanreactwithPIDAtodehalogenatethepolymeratroomtemperature.atleast60%oftheoriginaliodinedissociatingfromthepolymeruponreactionthebasetreatedPIDAmaterialsexhibitRamanspectraconsistentwithgraphiticcarbon,asignificantlyincreasedconductivity.ThereactionbetweenPIDAandLewisbasespresentsanovelchemicalmethodtogenerateone-dimensionalcarbonnanomaterialsundermildconditions.Ongoingexperimentsarefocusedonoptimizingthemethodtoa