Unusually high electron density in an intermolecular non-bonding region:Role of metal substrate  

作　　者：Chen-Guang Wang Zhi-Hai Cheng Xiao-Hui Qiu Wei Ji 

机构地区：[1]Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-nano Devices,Renmin University of China [2]CAS Key Laboratory of Standardization and Measurement for Nanotechnology,CAS Center for Excellence in Nanoscience,National Center for Nanoscience and Technology

出　　处：《Chinese Chemical Letters》2017年第4期759-764,共6页中国化学快报（英文版）

基　　金：supported by the Ministry of Science and Technology(MOST)of China(Nos.2012CB932704,2012CB933001);the National Natural Science Foundation of China(NSFC,Nos.11274380,91433103,21173058,11622437,61674171 and 21203038);supported by the Outstanding Innovative Talents Cultivation Funded Programs 2015 of Renmin University of China

摘　　要：It has been demonstrated that intermolecular interaction,crucial in a plenty of chemical and physical processes,may vary in the presence of metal surface.However,such modification is yet to be quantitatively revealed.Here,we present a systematical density functional theory study on adsorbed bis（para-pyridyl）acetylene（BPPA） tetramer on Au（111） surface.We observed unusually high electron density between two head-to-head N atoms,an intermolecular ＂non-bonded＂ region,in adsorbed BPPA tetramer.This exceptional electron density originates from the wavefunction hybridization of the two compressed N lone-electron-pair states of two BPPA,as squeezed by a newly revealed N-Au-N threecenter bonding.This bond,together with the minor contribution from N...H-C intermolecular hydrogen bonding,shortens the N-N distance from over 4 A to 3.30 A and offers an attractive lateral interacting energy of 0.60 eV,effectively to a surface-confined in-plane pressure.The overlapped non-bonding vvavefunction hybridization arising from the effective pressure induced by the N-Au-N three-center bonding,as not been fully recognized in earlier studies,was manifested in non-contact Atomic Force Microscopy.It has been demonstrated that intermolecular interaction,crucial in a plenty of chemical and physical processes,may vary in the presence of metal surface.However,such modification is yet to be quantitatively revealed.Here,we present a systematical density functional theory study on adsorbed bis（para-pyridyl）acetylene（BPPA） tetramer on Au（111） surface.We observed unusually high electron density between two head-to-head N atoms,an intermolecular ＂non-bonded＂ region,in adsorbed BPPA tetramer.This exceptional electron density originates from the wavefunction hybridization of the two compressed N lone-electron-pair states of two BPPA,as squeezed by a newly revealed N-Au-N threecenter bonding.This bond,together with the minor contribution from N...H-C intermolecular hydrogen bonding,shortens the N-N distance from over 4 A to 3.30 A and offers an attractive lateral interacting energy of 0.60 eV,effectively to a surface-confined in-plane pressure.The overlapped non-bonding vvavefunction hybridization arising from the effective pressure induced by the N-Au-N three-center bonding,as not been fully recognized in earlier studies,was manifested in non-contact Atomic Force Microscopy.

关 键 词：Density functional theory Lone electron pairs hybridization N-Au-N three-center bonding In-plane pressure NC-AFM 

分 类 号：O641.3[理学—物理化学]