title: Self-Assembled Dehydro[24]annulene Monolayers at the Liquid/Solid Interface: Toward On-Surface Synthesis of Tubular π-Conjugated Nanowires.
abstract: We have studied the self-assembly behavior of dehydro[24]annulene (D24A) derivatives 1, 2a-2d, and 3a-3c at the liquid/solid interface using scanning tunneling microscopy (STM). Both the relative placement and the nature of the four D24A substituents strongly influence the self-assembly pattern. Overall, the eight D24A derivatives examined in this study display seven types of 2D packing patterns. The D24A derivatives 1, 2a, and 3a have either two or four stearate groups and adopt face-on configurations of their macrocyclic cores with respect to the highly oriented pyrolytic graphite (HOPG) surface. Their 2D packing pattern is determined by the interchain spacings and number of stearate substituents. The D24A derivatives 2b-2d and 3b-3c bear hydrogen-bonding carbamate groups to further strengthen intermolecular interactions. Face-on patterns were also observed for most of these compounds, while an unstable edge-on self-assembly was observed in the case of 2b at room temperature. Stable edge-on self-assemblies of D24A derivatives were sought for this work as an important stepping stone to achieving the on-surface topochemical polymerization of these carbon-rich macrocycles into tubular π-conjugated nanowires. The overall factors determining the 2D packing patterns of D24As at the liquid/solid interface are discussed on the basis of theoretical simulations, providing useful guidelines for controlling the self-assembly pattern of future D24A macrocycles.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles , Los Angeles, California 90095-1569, United States.
authors.forename: Mitsuharu
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Division of Frontier Materials Science, Graduate School of Engineering Science, Osaka University , Toyonaka, Osaka 560-8531, Japan.
authors.forename: Zhaoqi
authors.initials: Z
authors.lastname: Guo
authors.affiliation: Division of Frontier Materials Science, Graduate School of Engineering Science, Osaka University , Toyonaka, Osaka 560-8531, Japan.|Department of Applied Chemistry, School of Science and Technology, Meiji University , 1-1-1 Higashimita, Tama-ku, Kawasaki 214-8571, Japan.
authors.forename: Kazukuni
authors.initials: K
authors.lastname: Tahara
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles , Los Angeles, California 90095-1569, United States.
authors.forename: Juliet F Khosrowabadi
authors.initials: JF
authors.lastname: Kotyk
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles , Los Angeles, California 90095-1569, United States.
authors.forename: Huan
authors.initials: H
authors.lastname: Nguyen
authors.affiliation: Division of Frontier Materials Science, Graduate School of Engineering Science, Osaka University , Toyonaka, Osaka 560-8531, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Gotoda
authors.affiliation: Division of Frontier Materials Science, Graduate School of Engineering Science, Osaka University , Toyonaka, Osaka 560-8531, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Iritani
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles , Los Angeles, California 90095-1569, United States.
authors.forename: Yves
authors.initials: Y
authors.lastname: Rubin
authors.affiliation: Division of Frontier Materials Science, Graduate School of Engineering Science, Osaka University , Toyonaka, Osaka 560-8531, Japan.
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Tobe