Alkane-assisted adsorption and assembly of phthalocyanines and porphyrins

In this paper it is demonstrated that the stabilizing effect of linear alka nes can be utilized to achieve very high stability in the adsorption and as sembly of planar organic molecules on inert surfaces under ambient conditio ns, by direct deposition from solutions. Using peripherally alkylated phtha locyanines and porphyrins as the examples, optimal resolutions can be achie ved with complex molecular systems. Submolecular features of the molecular cores and the interdigitated alkyl parts are clearly visible. Distinctly di fferent packing symmetries were also observed and could be attributed to th e intermolecular and adsorbate-substrate interactions. Appreciable contrast variations were also recorded with changing bias voltages. This approach c ould be adapted to the studies of other molecules to observe submolecular f eatures and could be helpful in obtaining two-dimensional assemblies of mon odispersed molecules, especially planar molecules.