摘要
Intramolecularvibrationsoflargemacromoleculesresideintheterahertzrange.Inparticular,proteinvibrationsarecloselyspacedinfrequency,resultinginanearlycontinuousvibrationaldensityofstates.Thisdensityofvibrationsinterfereswiththeidentificationofspecificabsorptionlinesandtheirsubsequentassociationwithspecificfunctionalmotions.Thischallengeiscompoundedwiththeabsorptionbeingdominatedbythesolventandlocalrelaxationalmotions.Astrategyforremovingtheisotropicrelaxationallossandisolatingspecificvibrationsistousealignedsamplesandpolarization-sensitivemeasurements.Here,wedemonstrateatechniquetorapidlyattaintheanisotropicresonantabsorbanceusingterahertztimedomainspectroscopyandaspinningsample.Thetechnique,modulatedorientation-sensitiveterahertzspectroscopy(MOSTS),hasanonzerosignalonlyforanisotropicsamples,asdemonstratedbyacomparisonbetweenasiliconwaferandawiregridpolarizer.Forsucroseandoxalicacidmolecularcrystals,theMOSTSresponseisinagreementwithmodeledresultsfortheintermolecularvibrations.Further,wedemonstratethat,eveninthepresenceofalargerelaxationalbackground,MOSTSisolatesunderlyingvibrationalresonances.
出版日期
2016年03月13日(中国期刊网平台首次上网日期,不代表论文的发表时间)