| Chapter 1. An overview of how self-assembly can be utilized in the molecular electronics and quantum computing fields.; Chapter 2. SAMs of the nitro-substituted oligo(phenylene-ethynylene) (OPE), 4,4'-(diethynylphenyl)-2'-nitro-1-benzenethiolate, on Au{lcub}111{rcub} were prepared. Assembly of the nitro-OPE SAM, either via acidic hydrolysis of the thioacetate derivative or from the thiol in neat solvent, produces a well-ordered SAM with a (√3 x √3) superlattice structure and an average molecular tilt of 32--39° from the surface normal. In contrast, when the nitro-OPE SAM is assembled by hydrolysis of the thioacetate derivative under basic conditions, extensive redox reactions arise in which oxidation of the S atoms occurs with accompanying reduction of -NO2 to -NH2, to form mixed composition SAMs. Further, the nitro-OPE SAM, regardless of the preparation method, shows significant chemical instability under storage in air and/or light exposure.; Chapter 3. SAMs of the isocyano derivative of 4,4 '-di(phenylene-ethynylene)benzene, a member of the "OPE" family of "molecular wires", have been prepared on Au{lcub}111{rcub} and Pd{lcub}111{rcub} surfaces. For assembly in oxygen-free environments with freshly deposited metal surfaces, infrared reflection spectroscopy (IRS) indicates the molecules assume a tilted structure with average tilt angles of 18--24° from the surface normal. Both IRS and x-ray photoelectron spectroscopy support a single sigma-type bond of the -NC group to the Au surface and a two-fold type of bonding to the Pd surface. Both SAMs show significant chemical instability with respect to exposure to typical ambient conditions.; Chapter 4. We demonstrate that it is possible to mimic the surface chemical properties of standard (∼150.0 nm thick) aluminum films using ultrathin Al2O3 films. Formed via the resistive evaporation of ∼0.7 nm Al metal and oxidized upon exposure to the laboratory ambient these films form equivalently on SiO2/Si, sapphire, quartz, and fused silica substrates. High quality stearic acid SAMs are formed on all 0.7 nm thick Al films.; Chapter 5. The chemical and structural properties of two o-nitroxide long-chain alkanoic acids self-assembled onto natively oxidized silver and aluminum surfaces are studied using infrared spectroscopy, single wavelength ellipsometry, contact angles and electron spin resonance. |
