Our group is interested in exploring how functional molecules (e.g. those composed of organic functional groups that do not necessarily lend themselves to an ordered 2D packing arrangement) can form well-ordered adlayers with functional properties. To this end. we have studied the formation of self assembled structures of 5-(N,N-didecyl-amino)-2.4- pentadienal (DAPDA, Figure 1) deposited on a highly ordered pyrolytic graphite (HOPG) surface. This molecule has two distinctive features that should dramatically affect its ordering on a surface. Neither of these have been systematically explored in ordered adlayers. First, the extended conjugation of the molecule gives it a large in-plane dipole moment as well as a high polarizability. Second, it contains two hydrocarbon tails, only one of which can lie coplanar with the conjugated moiety. Both molecularly resolved monolayer and bilayer structures were found using a combination of scanning tunneling microscopy and tapping mode atomic force microscopies.