We report a study on photo-ionization of benzene and aniline with incidental subsequent dissociation by the customized reflection time-of-flight mass spectrometer utilizing a deep ultraviolet 177.3 nm laser.Highly eff...We report a study on photo-ionization of benzene and aniline with incidental subsequent dissociation by the customized reflection time-of-flight mass spectrometer utilizing a deep ultraviolet 177.3 nm laser.Highly efficient ionization of benzene is observed with a weak C4H3+fragment formed by undergoing disproportional C-C bond dissociation.In comparison,a major C5H6+·fragment and a minor C6H6+·radical are produced in the ionization of aniline pertaining to the removal of CNH·and NH·radicals,respectively.First-principles calculation is employed to reveal the photo-dissociation pathways of these two molecules having a structural difference of just an amino group.It is demonstrated that hydrogen atom transfer plays an important role in the cleavage of C-C or C-N bonds in benzene and aniline ions.This study is helpful to understand the underlying mechanisms of chemical bond fracture of benzene ring and related aromatic molecules.展开更多
We briefly review recent results on photoemission spectroscopy based on the deep and vacuum ultraviolet diode pumped solid-state lasers which we have developed.Cascaded second harmonic generation with the nonlinear cr...We briefly review recent results on photoemission spectroscopy based on the deep and vacuum ultraviolet diode pumped solid-state lasers which we have developed.Cascaded second harmonic generation with the nonlinear crystal KBe2BO3F2(KBBF)is used to generate deep ultraviolet and vacuum ultraviolet laser radiation,which complements traditional incoherent light sources such as gas discharge lamps and synchrotron radiation,and has greatly improved resolution with respect to energy,momentum,and spin of photoemission spectroscopy.Many new functions have been developed with the advantages of high photon energy,narrow linewidth,high photon flux density,and so on.These have led to the observation of various new phenomena and the amassment of new data in the fields of high temperature superconductivity,topological electronics,Fermi semi-metals,and so forth.These laser systems have revived the field of photoemission spectroscopy and provided a new platform in this frontier research field.展开更多
基金supported by the National Natural Science Foundation of China(No.91536105,No.11174186,No.21722308)the National Project Development of Advanced Scientific Instruments Based on Deep Ultraviolet Laser Source(No.Y31M0112C1)+2 种基金the Beijing Natural Science Foundation(No.2192064)the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(No.QYZDB-SSW-SLH024)financial support from the Tianshan Scholar Program。
文摘We report a study on photo-ionization of benzene and aniline with incidental subsequent dissociation by the customized reflection time-of-flight mass spectrometer utilizing a deep ultraviolet 177.3 nm laser.Highly efficient ionization of benzene is observed with a weak C4H3+fragment formed by undergoing disproportional C-C bond dissociation.In comparison,a major C5H6+·fragment and a minor C6H6+·radical are produced in the ionization of aniline pertaining to the removal of CNH·and NH·radicals,respectively.First-principles calculation is employed to reveal the photo-dissociation pathways of these two molecules having a structural difference of just an amino group.It is demonstrated that hydrogen atom transfer plays an important role in the cleavage of C-C or C-N bonds in benzene and aniline ions.This study is helpful to understand the underlying mechanisms of chemical bond fracture of benzene ring and related aromatic molecules.
基金Project supported by the National Development Project for Major Scientific Research Facility(No.ZDYZ2012-2)the National Instrumentation Program(No.2012YQ120048)
文摘We briefly review recent results on photoemission spectroscopy based on the deep and vacuum ultraviolet diode pumped solid-state lasers which we have developed.Cascaded second harmonic generation with the nonlinear crystal KBe2BO3F2(KBBF)is used to generate deep ultraviolet and vacuum ultraviolet laser radiation,which complements traditional incoherent light sources such as gas discharge lamps and synchrotron radiation,and has greatly improved resolution with respect to energy,momentum,and spin of photoemission spectroscopy.Many new functions have been developed with the advantages of high photon energy,narrow linewidth,high photon flux density,and so on.These have led to the observation of various new phenomena and the amassment of new data in the fields of high temperature superconductivity,topological electronics,Fermi semi-metals,and so forth.These laser systems have revived the field of photoemission spectroscopy and provided a new platform in this frontier research field.
