资源描述：
《shirakawa-nobel.pdf》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、REVIEWSOFMODERNPHYSICS,VOLUME73,JULY2001NobelLecture:Thediscoveryofpolyacetylene®lmÐthedawningofaneraofconductingpolymers*HidekiShirakawaUniversityofTsukuba,Tsukuba,Ibaraki305-8577,Japan(Published20September2001)TheNobelPrizeinChemistry2000wasawardedforourdiscoveryanddevelopmentofconduc
2、tingpolymers,butthatdiscoveryonlyhappenedaftermuchworkonpolyacetylene.Inthislecture,Iwouldliketotalkabouttheearlyinvestigationsthatprecededandeventuallyledtothediscoveryofchemicaldoping.Idohopemytalkwillbeofuseforyou,theaudience,todeepenyourunderstandingofwhathadhappenedbeforeandhowwear
3、rivedattheideaofchemicaldoping.I.PROLOGUEdifferencebetweenlengthsofdoubleandsinglebondsdecreaseswithincreasingconjugationandthatallbondsIthasbeenrecognizedformanyyearsthataverylongtendtobeequalinlengthinanin®nitelylongpolyene.linearconjugatedpolyenemighthavevariousinterestingInotherword
4、s,onewouldexpectin®nitelylongone-properties,especiallyoptical,electrical,andmagneticdimensionalpelectronstoformahalf®lledband,ortheproperties.Apolyeneisanevennumberofmethynehighest-occupied(HO)andthelowest-unoccupied(LU)(vCH-)groups,covalentlybondedtoformalinearcar-p-electronbandstomerg
5、ewitheachother,leadingtobonchainbearingonepelectrononeachcarbonatom.metallicbehavior(Kuhn,1948;Bayliss,1952).IntheThereforethechemicalstructureofthepolyeneisbest1950s,however,itbecametheoreticallyclearthatapoly-representedbytheformulaH(CHvCH)nH,wherenenewithbondalternationisenergeticall
6、ymorestabledenotesthenumberofrepeatingunits.Recentlythethanonewithequidistantbonds(Ooshika,1957;wordpolyacetylenehasbecomemorepopularthanpoly-Longuet-HigginsandSalem,1959;Tsujietal.,1960;enebecausepolyacetylenesynthesizedbythepolymer-PopleandWalmsley,1962).Sincetwogeometricaliso-ization
7、ofacetylenehasbeenusedextensivelyasaspeci-mers,transandcis,arepossibleforeachdoublebond,menforvariousstudies.twoisomericforms,all-transandall-cis,areexpectedforPopleandWalmsley(1962)statedintheirarticlethatthetwoextremesofpolyacetyleneisomersasshownin``Althoughitisnotpossibleto
