Effect of Electrostatic Interactions on Metallophthalocyanine Single Molecular Arrays with <I>n</I>-Octadecyl Mercaptan Templates

Abstract

By changing central metal ions or by tuning the length of substituted alkyl chains, metallophthalocyanines or their derivatives exhibit various assembling behaviors when co-adsorbed with n-octadecyl mercaptan on highly oriented pyrolytic graphite surfaces. Repeated scanning tunneling microscopy experiments demonstrate that planar or short alkyl chain substituted MPcs could form single molecular arrays while phase separation occurred when non-planar or longer alkyl chain substituted MPcs were co-adsorbed with C18SH templates. The experimental results combined with the density functional theory calculations reveal that intermolecular electrostatic and van der Waals interactions play essential roles in the formation of single molecular arrays.