The scanning tunneling microscope (STM) constructed in the laboratory was utilized to observe the molecular arrangement of a new type of liquid crystalline molecule, 5-(p-dodecyloxyphenyl)pyrazine-2-carbonitrile (DOPPC), which has large dipole moments along the molecular axis. The DOPPC molecules adsorbed on a graphite substrate showed several different STM images with regular two-dimensional molecular arrays. They revealed a novel inter-digitated double-row structure, differing from the single-row and the double-row structures proposed for the STM images of cyanobiphenyl liquid crystals. Moreover, a computer calculation was conducted based on electrostatic multipole-multipole interaction and simulated the most energetically preferable molecular arrangement, which agreed well with the observed STM image.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)