A unique photoinduced change in the molecular ordering of a photochromic diarylethene derivative having amide groups was investigated at the liquid/highly oriented pyrolytic graphite (HOPG) interface by scanning tunneling microscopy (STM). Ordering of the diarylethene was stabilized by the hydrogen-bonded network of amide groups. The open- and the closed isomers formed characteristic stripe-patterned orderings; a different hydrogen-bonding network was formed in each case. In situ UV irradiation resulted in the exclusive formation of a third molecular ordering γ that is composed of the photoirreversible annulated isomer. No photoisomerized molecule was detected in the 2-D orderings, i.e., the open-ring isomer in the ordering of the closed-ring isomer and vice versa, despite the similarity in their molecular structures.
Diarylethene Self‐Assembled Monolayers: Cocrystallization and Mixing‐Induced Cooperativity Highlighted by Scanning Tunneling Microscopy at the Liquid/Solid Interface
concentration dependence of the surface coverage by using a cooperative model at the liquid/solidinterface. It was found that the annulated isomer has a very large equilibrium constant, which explains the predominantly observed ordering of the annulated isomer. It was also found that the presence of the closed‐ring isomer inducescooperativity into the formation of molecular ordering composed of the
Discrimination between Conglomerates and Pseudoracemates Using Surface Coverage Plots in 2D Self-Assemblies at the Liquid-Graphite Interface
作者:Naoki Maeda、Takashi Hirose、Kenji Matsuda
DOI:10.1002/anie.201611427
日期:2017.2.20
The two‐dimensional (2D) molecular ordering of two photochromic diarylethenes was investigated using scanning tunneling microscopy at the liquid–graphiteinterface. The racemic mixture of the closed‐ring isomer of one of the diarylethenes showed spontaneous separation of its enantiomers upon 2D crystallization, whereas that of the other diarylethene formed a pseudoracemic crystal in which two enantiomers