Rearrangements of metastable micelles to different molecular bilayers on planar graphite, mica, silicon, and hydrocarbon surfaces

Bis(2,2'-bipyridyl)(dihexadecyl-2-[2,2'-dipyridylmethylene] malonate) ruthe nium(II) dihexafluorophosphate, 1, formed multilayered micelles (denoted Cl s-micelles) upon sonication of aqueous suspensions. The Cls-micelles collap sed upon transfer to gold, mica, and silicon surfaces and rearranged to pla nar bilayers. These bilayers appeared in different arrangements under the a tomic force microscope. On graphite, the ruthenium headgroups and the alkyl chains lay flat and were both in direct contact with the substrate. On mic a and silicon wafers, upright-standing interdigitated bilayers were found e xclusively. Self-assembly of a dodecylsilane layer containing cracks on the silicon surface induced the formation of irregular double and triple layer s of 1. Bulk polyethylene or octadecylthiol layers on gold with smooth surf aces did not disrupt the micelles. C-18- and C-22-micelles made of the corr esponding homologues of 1 were much more stable on most surfaces, C-14-mice lles were destroyed on all surfaces. The variability of micelle -substrate interactions is discussed qualitatively.