氨基酸分子與溶劑間相互作用的理論研究.pdf

1、江南大學(xué)碩士學(xué)位論文氨基酸分子與溶劑間相互作用的理論研究姓名：任曉慧申請學(xué)位級別：碩士專業(yè)：應(yīng)用化學(xué)指導(dǎo)教師：王海軍20080601AbstractAbstractTheintermolecularinteractionsofthreedifferentbinarysystemswereinvestigatedwithDFTandAbinitiomethodsrespectivelyAccordingtothecalculationre

2、sultsofa11thesecomplexes，wehavetakenthesystematicallyanalysistoweakhydrogenbondingabouttheprincipleandmechanismTheB3m／631G宰andMP2／631GmethodswereperformedoncomplexesofDMFwithxylenes(o，ormorPxylene)，andsevenstableconfigur

3、ationswereobtainedwithnoimaginaryfrequenciesTheresultsindicatedthepresenceofdoubleC—HOhydrogenbondsbetweenDMFandxylenesintheseconformersandtheinteractionenergiesofhydrogenbondingoftheDMF—xylenesystemsdecreasedinthefollow

4、ingsequence：DMF勺xylene：alDMFmxylene：blDMFpxylene：c1Hydrogen—bondedcomplexesbetweenaminoacids(glycine，alanineandleucine)andDMFingasphasehavebeencarfiedoutattheB3LYP／631l礦宰theorylevelThestructures，bindingenergystretchingfr

5、equencyandbondcharacteristicsofthementionedcomplexeswerecalculatedTheNH，andCOOHgroupsofaminoacidsformsomedifferenttypesofhydrogenbondswithDMFmolecularaswellasalkylsidechainsThenearlylinearOHOandNHOcontactsarestrongerthan

6、aconventionalhydrogenbondinteractionwitll廿leirHOseparationbetween174and216ATheobservedweakerCHOHbondresultsinablueshiftintheCHstretchingfrequencyFurtherstudiesonhydrogen—bondedcomplexesbetweenaminoacids(glycine，alaninean

7、dleucine)andureaingasphasehavebeencarriedoutattheB3LYP／6311曠奉theorylevel111eNH2andCOOHgroupsofaminoacidsCanformseveraldifferenttypesofhydrogenbondswithureamolecularaswellasCaHandalkylsidechainsTheOHOcontactisthestrongest

8、hydrogenbondinteractionwimH0separationaround165Aanditsrelavantanglecloseto1760ThecloselylinearamidehydrogenbondsNHOandOHNstronglystabilizetheaminoacidureacomplexwimH0separationbetween189and238ATheweakerCHO／NHbondsarealso