TY - JOUR
T1 - Steering on-surface self-assembly of high-quality hydrocarbon networks with terminal alkynes
AU - Kepčija, Nenad
AU - Zhang, Yi Qi
AU - Kleinschrodt, Martin
AU - Björk, Jonas
AU - Klyatskaya, Svetlana
AU - Klappenberger, Florian
AU - Ruben, Mario
AU - Barth, Johannes V.
PY - 2013/2/28
Y1 - 2013/2/28
N2 - The two-dimensional (2D) self-assembly of 1,3,5-triethynyl-benzene (TEB) and de novo synthesized 1,3,5-tris-(4-ethynylphenyl)benzene (Ext-TEB) on Ag(111) was investigated by means of scanning tunneling microscopy (STM) under ultrahigh vacuum (UHV) conditions. Both 3-fold symmetric molecules form long-range ordered nanoporous networks featuring organizational chirality, mediated by novel, planar 6-fold cyclic binding motifs. The key interaction for the expression of the motifs is identified as C-H···π bonding. For Ext-TEB, an additional open-porous phase exists with the 3-fold motif. The nature of the underlying noncovalent bonding schemes is thoroughly analyzed by density functional theory (DFT) calculations including van der Waals corrections. The comparison of calculations focusing on isolated 2D molecular sheets and those including the substrate reveals the delicate balance between the attractive molecule-molecule interaction, mediated by both the terminal alkyne and the phenyl groups, and the molecule-substrate interaction responsible for the commensurability and the regularity of the networks. Comparison with bulk structures of similar molecules suggests that these strictly planar cyclic binding motifs appear only in 2D environments.
AB - The two-dimensional (2D) self-assembly of 1,3,5-triethynyl-benzene (TEB) and de novo synthesized 1,3,5-tris-(4-ethynylphenyl)benzene (Ext-TEB) on Ag(111) was investigated by means of scanning tunneling microscopy (STM) under ultrahigh vacuum (UHV) conditions. Both 3-fold symmetric molecules form long-range ordered nanoporous networks featuring organizational chirality, mediated by novel, planar 6-fold cyclic binding motifs. The key interaction for the expression of the motifs is identified as C-H···π bonding. For Ext-TEB, an additional open-porous phase exists with the 3-fold motif. The nature of the underlying noncovalent bonding schemes is thoroughly analyzed by density functional theory (DFT) calculations including van der Waals corrections. The comparison of calculations focusing on isolated 2D molecular sheets and those including the substrate reveals the delicate balance between the attractive molecule-molecule interaction, mediated by both the terminal alkyne and the phenyl groups, and the molecule-substrate interaction responsible for the commensurability and the regularity of the networks. Comparison with bulk structures of similar molecules suggests that these strictly planar cyclic binding motifs appear only in 2D environments.
UR - http://www.scopus.com/inward/record.url?scp=84874618818&partnerID=8YFLogxK
U2 - 10.1021/jp310606r
DO - 10.1021/jp310606r
M3 - Article
AN - SCOPUS:84874618818
SN - 1932-7447
VL - 117
SP - 3987
EP - 3995
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 8
ER -