PURPOSE: To provide an organic memory molecule capable of being utilized for a high-density recording device based on the principle of scanning tunnel microscope.
CONSTITUTION: An organic memory molecule of formulae I to III (R1 is a 1 to 8C alkyl or an aryl; R2 is a 1 to 8C alkyl containing an arbitrary functional group at the respective positions). The compound of formula I or III is produced from 1,4,5,8- tetrahydroxyanthraquinone as the starting substance and the compound of formula II is produced from 5,8-dihydroxy-1,4-naphthoquinone as the starting substance. When a metal base plate is immersed in a solution prepared by dissolving the compound of formula I to III in a suitable solvent, the compound is adsorbed and vertically oriented on the metal base plate so as to direct the S atom downward. If the surface of the base plate is washed after taking out the base plate, a recording medium composed of a monomolecular film vertically oriented on the metal base plate is produced. Recording, reading out and erase can be carried out by using the base plate as one electrode and operating the recording medium using this base plate electrode and a microprove electrode opposing to the base electrode and capable of being freely moved.