The influence of the functional modification (>CH2, > CO, > CN2) of alkylated anthrone derivatives of the structure of their two-dimensional crystals on the basal plane of graphite are studied by STM. In situ calibration against the hexagonal graphite lattice, analysis of Moire patterns and the study of domain boundaries are used to determine models for the observed structures. For 2-hexadecylanthraquinone two modifications with significantly different two-dimensional crystal structures have been observed as coexisting crystallites, which is a kinetic phenomenon. One of the structural modifications can only be explained by a coalescence of two space-filling models (oscillating model).