Direct observation of enantiospecific substitution in a two-dimensional chiral phase transition.
Initial stages of a chiral phase transition in the monolayer of a quinacridone derivative on the Au(111) surface were investigated by scanning tunneling microscopy at submolecular resolution. The prochiral molecules form a homochiral lamella phase at low coverages upon adsorption. A transition to a racemate lattice is observed with increasing coverage. Enantiomers of a homochiral lamella line become specifically substituted by opposite enantiomers such that a heterochiral structure evolves. Due to the higher density, lateral alkyl chains are bent away from the surface. Our findings are significant for the understanding and control of chiral phase transitions in related molecular systems like liquid crystals.
Yang
Bing
B
Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Wang
Yeliang
Y
Cun
Huanyao
H
Du
Shixuan
S
Xu
Mingchun
M
Wang
Yue
Y
Ernst
Karl-Heinz
KH
Gao
Hong-Jun
HJ