STM investigations of physisorbed monolayers of dialkoxy-substituted aromatics

The molecular adhesion layers studied in this work are comprised of symmetr ical dialkoxy-substituted aromatics of the anthracene and biphenyl type, se lected for their chemical and structural properties, ie. 2,6-bis(octyloxy) anthracene, 2,6-bis(dodecyloxy) anthracene, 4,4'-bis(decyloxy) biphenyl and 4,4'-bis(hexadecyloxy) biphenyl. The characterization of these physisorbed monolayers is presented, and we propose plane-filling packing structure mo dels for the 2D crystals. The models are based on sub Angstrom calibrated i mages of the reproducibly scanned adhesion layers. The molecular 2D crystal s formed yield domains of varying sizes.