The use of single molecules as ultra small electronic devices has been suggested as a means of surpassing present size limitations inherent to semiconductor microelectronics. The orientation of single, organic, thiol-functionalized, pi-electron conjugated oligomers ("molecular wires") on metal surfaces is important to testing their electronic properties. Oligomer orientation on flat gold surfaces was determined here by infrared reflection spectroscopy (IRS). IRS showed that oligomers of the length necessary for electrode-oligomer-electrode contact (;Selenols are investigated as an alternative method for attaching molecular wires to gold surfaces. Acetyl protecting groups are shown to produce alkyl SAMs that are more conformationally ordered than those using carbonate or carbamate groups. SAMs of alkaneselenols on gold are shown to have nearly identical orientation (tilt ;In a preliminary study, alkali metal doping was shown to be possible for nitro-terminated molecular wire SAMs. However, neither the IRS experiments nor DFT calculations on simple radical anions were able to determine the exact nature of species in the doped SAM.;A system of rules for self-assembling nanometer-scale structures employing fully conjugated organic oligomers is developed and presented.
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