title: Single-Molecule Investigations of Conformation Adaptation of Porphyrins on Surfaces.
abstract: The porphyrin macrocyclic core features dynamic conformational transformations in free space because of its structural flexibility. Once attached to a substrate, the molecule-substrate interaction often restricts this flexibility and stabilizes the porphyrin in a specific conformation. Here using molecular dynamic and density-functional theory simulations and scanning tunneling microscopy and spectroscopy, we investigated the conformation relaxation and stabilization processes of two porphyrin derivatives (5,15-dibromophenyl-10,20-diphenylporphyrin, Br2TPP, and 5,15-diphenylporphyrin, DPP) adsorbed on Au(111) and Pb(111) surfaces. We found that Br2TPP adopts either dome or saddle conformations on Au(111) but only the saddle conformation on Pb(111), whereas DPP deforms to a ruffled conformation on Au(111). We also resolved the structural transformation pathway of Br2TPP from the free-space conformations to the surface-anchored conformations. These findings provide unprecedented insights revealing the conformation adaptation process. We anticipate that our results may be useful for controlling the conformation of surface-anchored porphyrin molecules.
authors.affiliation: Department of Physics, The Hong Kong University of Science and Technology , Hong Kong, China.|Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration & Reconstruction , Hong Kong, China.
authors.forename: Qiushi
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration & Reconstruction , Hong Kong, China.|Department of Chemistry, The Hong Kong University of Science and Technology , Hong Kong, China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zheng
authors.affiliation: Department of Physics, The Hong Kong University of Science and Technology , Hong Kong, China.|Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration & Reconstruction , Hong Kong, China.
authors.forename: Guowen
authors.initials: G
authors.lastname: Kuang
authors.affiliation: Department of Physics, The Hong Kong University of Science and Technology , Hong Kong, China.
authors.forename: Weihua
authors.identifier: http://orcid.org/0000-0002-2269-1952
authors.initials: W
authors.lastname: Wang
authors.affiliation: Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration & Reconstruction , Hong Kong, China.|Department of Chemistry, The Hong Kong University of Science and Technology , Hong Kong, China.
authors.forename: Lizhe
authors.initials: L
authors.lastname: Zhu
authors.affiliation: Department of Physics, South University of Science and Technology of China , Nanshan District, Shenzhen, Guangdong 518055, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Pang
authors.affiliation: Department of Physics, South University of Science and Technology of China , Nanshan District, Shenzhen, Guangdong 518055, China.
authors.forename: Xingqiang
authors.initials: X
authors.lastname: Shi
authors.affiliation: Shanghai Key Laboratory of Functional Materials Chemistry and Institute of Fine Chemicals, East China University of Science and Technology , Meilong Road 130, Shanghai, China.
authors.forename: Xuesong
authors.initials: X
authors.lastname: Shang
authors.affiliation: Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration & Reconstruction , Hong Kong, China.|Department of Chemistry, The Hong Kong University of Science and Technology , Hong Kong, China.
authors.forename: Xuhui
authors.initials: X
authors.lastname: Huang
authors.affiliation: Shanghai Key Laboratory of Functional Materials Chemistry and Institute of Fine Chemicals, East China University of Science and Technology , Meilong Road 130, Shanghai, China.
authors.forename: Pei Nian
authors.initials: PN
authors.lastname: Liu
authors.affiliation: Department of Physics, The Hong Kong University of Science and Technology , Hong Kong, China.|Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration & Reconstruction , Hong Kong, China.
authors.forename: Nian
authors.identifier: http://orcid.org/0000-0001-5693-4011
authors.initials: N
authors.lastname: Lin
mesh_terms: D000327:Adsorption; D016252:Microscopy, Scanning Tunneling; D008958:Models, Molecular; D008968:Molecular Conformation; D036103:Nanotechnology; D011166:Porphyrins / Q000737:chemistry*; D013499:Surface Properties
chemical_list: C540777:5,15-diphenylporphyrin; D011166:Porphyrins