Jianfeng Zhao, Yibao Li, Zong-qiong Lin
May 12, 2010
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0
Influential Citations
22
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Journal
Journal of Physical Chemistry C
Abstract
A series of tetratopic C2-symmetric quasi-planar oligomeric phenylene−ethynylenes bearing carboxylic groups (OPE-COOHs), including the shortest 1,4-di((3,5-dicarboxyphenyl)ethynyl)benzene (TCB), midlength 4,4′-di((3,5-dicarboxyphenyl)ethynyl)biphenyl (TCBP), and the longest 4,4′′-di((3,5-dicarboxyphenyl)ethynyl)-p-terphenyl (TCTP), were synthesized via Pd(PPh3)4−CuI-catalyzed Sonogashira coupling reaction. Their molecular structures were characterized by nuclear magnetic resonance spectroscopy (NMR), matrix-assisted laser desorption−ionization time-of-flight mass spectroscopy (MALDI-TOF-MS), and element analyses. The molecule length effect of OPE-COOHs on two-dimensional (2D) assemblies at the octanoic acid−highly ordered pyrolytic graphite (HOPG) interface was investigated by scanning tunneling microscopy (STM) technique at ambient temperature and simulated by molecular modeling. The patterns and domain sizes of OPE-COOHs strongly depend on their molecule length with Kagome network only for TCB and paral...