Phototriggered formation and disappearance of surface-confined self-assembly composed of photochromic 2-thienyl-type diarylethene: a cooperative model at the liquid/solid interface.

A photoresponsive self-assembly on a 2-D surface was investigated by scanning tunnelling microscopy (STM). The open-ring isomer of a diarylethene derivative showed an abrupt ordering formation at a critical concentration, which was successfully reproduced by a cooperative model based on Langmuir-type adsorption.