title: Influence of substituents on two-dimensional ordering of oligo(phenylene-ethynylene)s--a scanning tunneling microscopy study.
abstract: Two-dimensional (2D) assemblies of alkoxy-substituted oligo(phenylene-ethynylene)s bearing different substituents adsorbed on highly oriented pyrolytic graphite (HOPG) were studied by using scanning tunneling microscopy. It was found that the introduction of different endgroups or a biethynylene linkage into oligo(phenylene-ethynylene)s can significantly change their 2D ordering on HOPG. The carboxylic endgroups can direct the conjugated oligomers to form ordered lines through intermolecular hydrogen bonding. The possibility of controlling the 2D assemblies of conjugated molecules is of importance in designing organic optoelectronic devices.
authors.affiliation: Key Lab of Organic Optoelectronics and Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing 100084, People's Republic of China.
authors.forename: Zhongcheng
authors.initials: Z
authors.lastname: Mu
authors.forename: Xunyu
authors.initials: X
authors.lastname: Yang
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Wang
authors.forename: Xi
authors.initials: X
authors.lastname: Zhang
authors.forename: Jinling
authors.initials: J
authors.lastname: Zhao
authors.forename: Zhishan
authors.initials: Z
authors.lastname: Bo