title: Organometallic Bonding in an Ullmann-Type On-Surface Chemical Reaction Studied by High-Resolution Atomic Force Microscopy.
abstract: The on-surface Ullmann-type chemical reaction synthesizes polymers by linking carbons of adjacent molecules on solid surfaces. Although an organometallic compound is recently identified as the reaction intermediate, little is known about the detailed structure of the bonded organometallic species and its influence on the molecule and the reaction. Herein atomic force microscopy at low temperature is used to study the reaction with 3,9-diiododinaphtho[2,3-b:2',3'-d]thiophene (I-DNT-VW), which is polymerized on Ag(111) in vacuum. Thermally sublimated I-DNT-VW picks up a Ag surface atom, forming a CAg bond at one end after removing an iodine. The CAg bond is usually short-lived, and a CAgC organometallic bond immediately forms with an adjacent molecule. The existence of the bonded Ag atoms strongly affects the bending angle and adsorption height of the molecular unit. Density functional theory calculations reveal the bending mechanism, which reveals that charge from the terminus of the molecule is transferred via the Ag atom into the organometallic bond and strengths the local adsorption to the substrate. Such deformations vanish when the Ag atoms are removed by annealing and CC bonds are established.
authors.affiliation: International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1, Namiki, Tsukuba, Ibaraki, 305-0044, Japan. KAWAI.Shigeki@nims.go.jp.|PRESTO, Japan Science and Technology Agency, 4-1-8, Honcho, Kawaguchi, Saitama, 332-0012, Japan. KAWAI.Shigeki@nims.go.jp.|Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland. KAWAI.Shigeki@nims.go.jp.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Kawai
authors.affiliation: Department of Physics, Shahid Beheshti University, G. C., Evin, 19839, Tehran, Iran. ali_sadeghi@sbu.ac.ir.
authors.forename: Ali
authors.initials: A
authors.lastname: Sadeghi
authors.affiliation: PRESTO, Japan Science and Technology Agency, 4-1-8, Honcho, Kawaguchi, Saitama, 332-0012, Japan. tokamoto@k.u-tokyo.ac.jp.|Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8561, Japan. tokamoto@k.u-tokyo.ac.jp.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Okamoto
authors.affiliation: Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8561, Japan.
authors.forename: Chikahiko
authors.initials: C
authors.lastname: Mitsui
authors.affiliation: Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland.
authors.forename: Rémy
authors.initials: R
authors.lastname: Pawlak
authors.affiliation: Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland.
authors.forename: Tobias
authors.initials: T
authors.lastname: Meier
authors.affiliation: Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8561, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Takeya
authors.affiliation: Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland.
authors.forename: Stefan
authors.initials: S
authors.lastname: Goedecker
authors.affiliation: Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland.
authors.forename: Ernst
authors.initials: E
authors.lastname: Meyer
keywords: atomic force microscopy; density functional theory calculations; on-surface chemical reaction; organometallic bond