Controlling Molecular Growth between Fractals and Crystals on Surfaces.
Recent studies demonstrate that simple functional molecules, which usually form two-dimensional (2D) crystal structures when adsorbed on solid substrates, are also able to self-assemble into ordered openwork fractal aggregates. To direct and control the growth of such fractal supramolecules, it is necessary to explore the conditions under which both fractal and crystalline patterns develop and coexist. In this contribution, we study the coexistence of Sierpiński triangle (ST) fractals and 2D molecular crystals that were formed by 4,4″-dihydroxy-1,1':3',1″-terphenyl molecules on Au(111) in ultrahigh vacuum. Growth competition between the STs and 2D crystals was realized by tuning substrate and molecular surface coverage and changing the functional groups of the molecular building block. Density functional theory calculations and Monte Carlo simulations are used to characterize the process. Both experimental and theoretical results demonstrate the possibility of steering the surface self-assembly to generate fractal and nonfractal structures made up of the same molecular building block.
Xue
X
Zhang
Na
N
Li
Gao-Chen
GC
Gu
Hao
H
Wang
Department of Theoretical Chemistry, Maria-Curie Skłodowska University , Pl. M.C. Skłodowskiej 3, 20-031 Lublin, Poland.
Damian
D
Nieckarz
Department of Theoretical Chemistry, Maria-Curie Skłodowska University , Pl. M.C. Skłodowskiej 3, 20-031 Lublin, Poland.
Paweł
P
Szabelski
Yang
Y
He
Yu
Y
Wang
Chao
C
Xie
Zi-Yong
ZY
Shen
School of Physics, Huazhong University of Science and Technology , 1037 Luoyu Road, Wuhan 430074, China.|Beida Information Research (BIR) , Tianjin 300457, China.
Jing-Tao
JT
Lü
Groupe Matriaux Crystallins sous Contrainte, CEMES-CNRS , Boîte Postale 94347, 31055 Toulouse, France.
Hao
H
Tang
Lian-Mao
LM
Peng
Beida Information Research (BIR) , Tianjin 300457, China.
Shi-Min
SM
Hou
SPURc, 1 CREATE Way , #15-01, CREATE Tower, Singapore 138602.
Kai
K
Wu
Beida Information Research (BIR) , Tianjin 300457, China.
Yong-Feng
YF
Wang
Sierpiński triangle; fractal; hydrogen bond; molecular crystal; scanning tunneling microscopy; self-assebly