Homochiral to heterochiral transition in a pentahelicene monolayer on Bi(111)
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Updated: Oct 16, 2025

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
Published on: May 15, 2017
Jing-Xiang Xia1, Zuo Li1,2, Qing Han1
1School of Physical Science and Technology, Southwest University, Chongqing, 400715, China. jzwangcn@swu.edu.cn.
Abstract:
We report the nucleation and two dimensional (2D) crystallization of the helical aromatic hydrocarbon pentahelicene ([5]H) on the semimetallic Bi(111) surface studied via low-temperature scanning tunneling microscopy. Individual homochiral dimers and heterochiral trimers appear on the substrate at a low coverage. With an increase in the coverage, a chiral phase transition takes place from the 2D conglomerate of [5]H dimers to the 2D racemate of [5]H trimers. The heterochiral [5]H trimers reveal a wavy arrangement due to the swing of 5[H] trimer rows after every second or third trimers. The swing mechanism of the trimer rows can be attributed to the steric repulsion between the adjacent trimers with same handedness.
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