TY - JOUR
T1 - Phase-separated indenofluorene arrays stabilized by hydrogen and halogen bonds on Au(111)
AU - Park, Jong Hwan
AU - Chang, Min Hui
AU - Jang, Won Jun
AU - Han, Seungwu
AU - Kahng, Se Jong
N1 - Funding Information:
The authors gratefully acknowledge financial support from the National Research Foundation of Korea (Grants Nos.
Publisher Copyright:
© 2021 Author(s).
PY - 2022/1/1
Y1 - 2022/1/1
N2 - Indenofluorene, which consists of a 6-5-6-5-6 fused-ring structure, is a semiconducting molecule with possible applications in optoelectronic devices. Bulk crystal structures, molecular front orbitals, and on-surface polymerized indenofluorene have recently been studied, but self-assembled structures on the surface have not yet been reported. Here, we report the array structure of 2,8-dibromoindeno[1,2-b]fluorene-6,12-dione on Au(111) studied using scanning tunneling microscopy. We proposed an alternating-tread stair structure as the molecular model for the monolayer molecular islands, which show strong shape anisotropy. The model can be explained by four O⋯H hydrogen bonds and one Br⋯Br halogen bond per molecule, as supported by density functional theory calculations. Although they prefer intermixed heteroprochiral structures in bulk layers, our study shows that these molecules can form phase-separated homoprochiral structures on the surface, leading to potential applications in molecular chiral separation.
AB - Indenofluorene, which consists of a 6-5-6-5-6 fused-ring structure, is a semiconducting molecule with possible applications in optoelectronic devices. Bulk crystal structures, molecular front orbitals, and on-surface polymerized indenofluorene have recently been studied, but self-assembled structures on the surface have not yet been reported. Here, we report the array structure of 2,8-dibromoindeno[1,2-b]fluorene-6,12-dione on Au(111) studied using scanning tunneling microscopy. We proposed an alternating-tread stair structure as the molecular model for the monolayer molecular islands, which show strong shape anisotropy. The model can be explained by four O⋯H hydrogen bonds and one Br⋯Br halogen bond per molecule, as supported by density functional theory calculations. Although they prefer intermixed heteroprochiral structures in bulk layers, our study shows that these molecules can form phase-separated homoprochiral structures on the surface, leading to potential applications in molecular chiral separation.
UR - http://www.scopus.com/inward/record.url?scp=85120641079&partnerID=8YFLogxK
U2 - 10.1116/6.0001345
DO - 10.1116/6.0001345
M3 - Article
AN - SCOPUS:85120641079
SN - 0734-2101
VL - 40
JO - Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
JF - Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
IS - 1
M1 - 013201
ER -