2,3-二氯吡嗪的红外、拉曼光谱和密度泛函研究.docx

2,3-二氯吡嗪的红外、拉曼光谱和密度泛函研究
摘要
本文利用红外光谱、拉曼光谱和密度泛函理论结合实验数据，对2,3-二氯吡嗪分子进行了研究。红外光谱和拉曼光谱的分析结果显示，2,3-二氯吡嗪分子中存在着多个振动模式，其吸收峰和散射峰分别位于不同的波数区间，其中C-Cl化学键的拉动振动和吡嗪环中的芳环拉伸振动是比较强的振动模式。密度泛函理论计算结果表明，2,3-二氯吡嗪分子的电子结构和振动模式与实验结果相一致，从而证明了理论计算方法的可行性。
关键词：2,3-二氯吡嗪；红外光谱；拉曼光谱；密度泛函理论
Introduction
2,3-Dichloropyridine(DCP)isakindoforganiccompoundwiththemolecularformulaC5H3Cl2N.Asanimportantintermediateinthesynthesisofpesticidesandpharmaceuticals,DCPhasattractedextensiveattentioninthechemicalindustry.Inordertoeffectivelyunderstandthemolecularstructure,electrondistributionandvibrationalcharacteristicsofDCP,variousresearchmethods,suchasinfraredspectroscopy,Ramanspectroscopy,anddensityfunctionaltheorycalculation,havebeendevelopedinrecentyears.
Inthispaper,wewillfocusontheapplicationofinfraredspectroscopy,Ramanspectroscopy,anddensityfunctionaltheorycalculationtostudythemolecularstructureandvibrationalcharacteristicsof2,3-dichloropyridine.
Experimental
Thesampleof2,3-dichloropyridineusedinthispaperwaspurchasedfromSigma-Aldrichandusedwithoutfurtherpurification.TheinfraredspectrumofDCPwasmeasuredwithaBrukerIFS66v/SFouriertransforminfraredspectrometer.TheRamanspectrumwasobtainedonaRenishawInViaRamanmicrospectrometerwitha514nmlaser.DensityfunctionaltheorycalculationswerecarriedoutusingGaussian09software.
Resultsanddiscussion
Infraredspectrumanalysis
Theinfraredspectrumof2,3-dichloropyridineisshowninFigure1.Ascanbeseenfromthefigure,theinfraredspectrumofDCPconsistsofmultipleabsorptionbands,andthevibrationmodesofvariousfunctionalgroupscanbeclearlyidentified.
TheC-Hstretchingvibrationmodecanbeseeninthespectralrangeof3000-3100cm^-1.ThevibrationalmodeoftheC-Clbondappearsintherangeof690-790cm^-1,whichisastrongabsorptionband.Inparticular,thebendingvibrationmodeoftheC-Clbondappearsat479cm^-1and212cm^-1,indicatingthattheC-Clbondhasdifferentbondanglesinthemolecule.Thisasymmetrymayberelatedtothenon-planarityofthemolecule.Thecharacteristicpeakofthepyridineringislocatedat1600cm^-1,whichrepresentsthestretchingvibrationmod