Direct observation of the stacked structure in substituted copper phthalocyanine LB films with STM

The in-plane molecular structures of octa-alkyl substituted copper phthalocyanine LB films deposited on graphite have been resolved with a scanning tunnelling microscope (STM). The face-to-face stacking of Pc macrocycles has been observed in the topographies of R₈PcCu monolayers. The stacking period was found to be 3.8–4 Å and the molecular rows were separated by 19 Å and 16 A for (C₆H₁₃)PcCu and (C₅H₁₁)PcCu respectively.