The interaction between a probing tip and an adsorbed molecule can significantly impact the molecular chemical structure and even induce its motion on the surface.In this study,the tip-induced bond weakening,tilting,a...The interaction between a probing tip and an adsorbed molecule can significantly impact the molecular chemical structure and even induce its motion on the surface.In this study,the tip-induced bond weakening,tilting,and hopping processes of a single molecule were investigated by sub-nanometre resolved tip-enhanced Raman spectroscopy(TERS).We used single carbon monoxide(CO)molecules adsorbed on the Cu(100)surface as a model system for the investigation.The vibrational frequency of the C−O stretching mode is always redshifted as the tip approaches,revealing the weakening of the C−O bond owing to tip−molecule interactions.Further analyses of both the vibrational Stark effect and TERS imaging patterns suggest a delicate tilting phenomenon of the adsorbed CO molecule on Cu(100),which eventually leads to lateral hopping of the molecule.While a tilting orientation is found toward the hollow site along the[110]direction of the Cu(100)surface,the hopping event is more likely to proceed via the bridge site to the nearest Cu neighbour along the[100]or[010]direction.Our results provide deep insights into the microscopic mechanisms of tip−molecule interactions and tip-induced molecular motions on surfaces at the single-bond level.展开更多
基金supported by the National Key R&D Program of China(Grant Nos.2021YFA1500500 and 2016YFA0200600)National Natural Science Foundation of China(Grant No.21790352)+2 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB36000000)the Anhui Initiative in Quantum Information Technologies(Grant No.AHY090000)support from the China National Postdoctoral Program for Innovative Talents(No.BX2021282).
文摘The interaction between a probing tip and an adsorbed molecule can significantly impact the molecular chemical structure and even induce its motion on the surface.In this study,the tip-induced bond weakening,tilting,and hopping processes of a single molecule were investigated by sub-nanometre resolved tip-enhanced Raman spectroscopy(TERS).We used single carbon monoxide(CO)molecules adsorbed on the Cu(100)surface as a model system for the investigation.The vibrational frequency of the C−O stretching mode is always redshifted as the tip approaches,revealing the weakening of the C−O bond owing to tip−molecule interactions.Further analyses of both the vibrational Stark effect and TERS imaging patterns suggest a delicate tilting phenomenon of the adsorbed CO molecule on Cu(100),which eventually leads to lateral hopping of the molecule.While a tilting orientation is found toward the hollow site along the[110]direction of the Cu(100)surface,the hopping event is more likely to proceed via the bridge site to the nearest Cu neighbour along the[100]or[010]direction.Our results provide deep insights into the microscopic mechanisms of tip−molecule interactions and tip-induced molecular motions on surfaces at the single-bond level.
