title: Single-molecule resolution of an organometallic intermediate in a surface-supported Ullmann coupling reaction.
abstract: We have studied the organometallic intermediate of a surface-supported Ullmann coupling reaction from 4, 4″-dibromo-p-terphenyl to poly(para-phenylene) by scanning tunneling microscopy/spectroscopy and density functional theory calculations. Our study reveals at a single-molecular level that the intermediate consists of biradical terphenyl (ph)(3) units that are connected by single Cu atoms through C-Cu-C bridges. Upon further increasing the temperature, the neighboring biradical (ph)(3) units are coupled by C-C bonds forming poly(para-phenylene) oligomers while the Cu atoms are released.
authors.affiliation: Department of Physics, The Hong Kong University of Science and Technology, Hong Kong, China.
authors.forename: Weihua
authors.initials: W
authors.lastname: Wang
authors.forename: Xingqiang
authors.initials: X
authors.lastname: Shi
authors.forename: Shiyong
authors.initials: S
authors.lastname: Wang
authors.forename: Michel A
authors.initials: MA
authors.lastname: Van Hove
authors.forename: Nian
authors.initials: N
authors.lastname: Lin