Infrared Spectroscopy of Neutral and Cationic Pyrrolidine Monomer in Supersonic Jet  

作　　者：Min Xie Zhao-li Zhang Yu Zhang Xiao-nan Sun Fu-fei Sun Yong-jun Hu 

机构地区：[1]MOE Key Laboratory of Laser Life Science&Guangdong Provincial Key Laboratory of Laser Life Science,Guangzhou Key Laboratory of Spectral Analysis and Functional Probes,College of Biophotonics,South China Normal University,Guangzhou 510631,China

出　　处：《Chinese Journal of Chemical Physics》2020年第1期43-47,I0005,I0006,共7页化学物理学报（英文）

基　　金：the National Natural Science Foundation of China(No.U1732146,No.21273083);the Project under Scientific and Technological Planning Grant(No.201805010002)by Guangzhou City.

摘　　要：Pyrrolidine,a five membered heterocyclic molecule,is widely existing in organism.Herein,infrared spectra of pyrrolidine monomer in neutral and cationic states were obtained by vacuum ultraviolet ionization,infrared photodissociation and time of flight mass spectrometry.Both in neutral and cationic states,it is found that their CH stretching vibration bands are red shifted.In the IR spectrum of neutral pyrrolidine,because the electric dipole moment of NH is small,we have not observed the NH stretching vibration bands.However,the NH stretching vibration band of pyrrolidine is greatly enhanced after ionization,and this band red-shifts compared with the previous experiment.The red shifts of CH stretching vibrations in neutral and cationic states are caused by the negative and positive hyperconjugation,respectively.The enhancement and red shift of the NH stretching band are owing to the ejection of the electrons on the N atom after ionization.Through the calculations,it is found that the acidity of the CH bond is a little stronger than that of NH bond.These kinds of studies would be helpful to understand the intrinsic properties of biomolecules in neutral and cationic states,and to provide reference for the further study of living organic macromolecules.

关 键 词：IR spectroscopy HYPERCONJUGATION Cationic state CH bond acidity Gas phase 

分 类 号：O641.3[理学—物理化学] O657.33[理学—化学]