简介：

简介：Thenoveldicyanateesterresincontainingnaphthaleneunit(DNCY)wassynthesized,andcharacterizedbyFT-IR,^1H-NMR,^13C-NMRandelementalanalysis(EA),ThethermalpropertiesofDNCYresinwasstudiedbythermaldegradationanalysisataheatingrateof10℃/min^-1inN2andair,TheDNCYrdsinexhibitedbetterthermalandthrmal-oxidativestabilitythanbisphenolAdicyanate(BACY)resin.

简介：

简介：Aseriesofpolybenzoxazoles(co)polymersbearingcrankshaftunitsinthemainchainwassynthesizedbytheconventionalsolutionpolycondensationof4,6-diaminorescinoldihydrochloride,terephthalicacid(TA)and2,6-naphthalenedicarboxylicacid(NDA).Allofthepolymersshowlyotropicliquidcrystalbehaviorinpolyphosphoricacid(PPA)andmethanesulfonicacid(MSA).Thepolybenzoxazolesexhibitanexcellentthermalresistancealthoughthecrankshaftmonomerhasbeenintroducedintothepolymerbackbone.Thetemperatureforthe5%weightlossofallthepolymersisabove600℃.TheX-raydiffractionanalysisresultsshowthattheseriesofthepolymershasahighcrystallinity.TheintroductionofNDAmakesaslightdecreaseinthethermalresistanceofthepolymers.ThemaximumabsorptionpeakintheUV-Visspectracanbeadjustedaccordingtotheamountof2,6-naphthaleneunitsinthepolymers,whichindicatesthepotentialapplicationofthepolymersasoptoelectriematerials.

简介：

简介：ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｒｅｃｅｎｔｙｅａｒｓ，Ｌａｎｇｍｕｉｒ－Ｂｌｏｄｇｅｔ（ＬＢ）ｆｉｌｍｓｈａｖｅａｔｒａｃｔｅｄｍｕｃｈａｔｅｎｔｉｏｎｂｅｃａｕｓｅｏｆｔｈｅｉｒｐｏｓｉｂｉｌｉｔｉｅｓａｓｆｕｎｃｔｉｏｎａｌｍｏｌｅｃｕｌａｒｄｅｖ...

简介：Inthispaper,2-isopropylnaphthalenehasbeensynthesizedbythereactionofnaphthaleneandisopropylbromide,usingtriethylaminehydrochloride-aluminumchlorideionicliquidasthecatalyst.Theeffectofthecatalystcomposition,thereactiontime,thereactiontemperature,theionicliquiddosage,aswellasthemolarratioofthereagentsonthe2-isopropylnaphthaleneyieldwassystematicallyinvestigated.Theoptimalreactionconditionscover:anAlCl3toEt3NHClratioof2.0,areactiontimeof3h,areactiontemperatureof15.0℃,avolumefractionofionicliquidtothemixture(isopropylbromide,n-dodecaneandn-hexane)of9%,andanaphthalene/isopropylbromidemolarratioof4.0.Undertheoptimalreactionconditions,theconversionofisopropylbromidereached98%andtheselectivityof2-isopropylnaphthalenewasequalto80%.ThetestresultsverifiedgoodcatalyticactivityuponusingEt3NHCl-AlCl3ionicliquidasthecatalystforalkylationofnaphthalenewithisopropylbromide.Theactivityoftheionicliquidremainsunchangedafterithasbeenrecycledfor4times.

简介：Thefluorescencequenchingofnaphthalene(2)and1,3-di(α-naphthyl)propane(1)byRNAandbasesinmethanol-water(v:v=1:1)binarysolventsinthepresenceorabsenceofcyclodex-trin(CD)hasbeeninvestigated.Theresultsshowthatboththemonomerandexcimerfluorescenceof1canbequenchedbythesequenchers.Thequenchingandratesdependonthequencherandtem-perature.Itisshownthatthereisacriticaltemperature(Tc)foreachquencher.BelowTc,theexcimerfluorescencespectrashowvibrationalstructuresandtheStern-Volmerplotsarestraightlines(forura-cilandcytosine);whileabovetheTc,thevibrationalstructuresdisappearandtheStern-Volmerplotsdeviatefromlinearityandcurveupward.Theformerisastaticprocess;whilethelatterisamixtureofbothstaticanddynamicprocesses.Theadditionofα-CDhasnoeffectonthefinestructure,whereasβ-CDpreventstheappearanceofthisstructureefficiently.Thequenchingratesbothforthemonomerandexcimerof1bybasesexceptcytosineinthepresenceofβ-CDatambienttemperaturearenotchanged;thequenchingoffluorescenceof1byRNAinthepresenceofβ-CD,however,ishindered.Time-resolvedfluorescencestudyshowsthattheexcimerfinestructuresappearfromthezerotime.Theintensityoffinestructuresdependonthefractionofwater(φ)inbinarysolvents,anditisindependentofthepHvalueofthesolvents.ItissuggestedthatbasesandRNAinducedaggregates(perhapsmicrocrystal)areformed,inwhichthemotionofmolecules1islimited.