In the Bonnell group, we utilize several self-assembly techniques to create novel functional surfaces to;
- Elucidate fundamental chemical and physical adsorbate-substrate interactions
- Isolate individual molecules/biomolecules for photo-induced charge transport measurements
Figure from Shreiber, F. Prog. Surf. Sci. 65 (2000), 151-256.
Other key references: Ulman, A., Chem. Rev. 96 (1996), 1533-1554. Smith et al. , Prog. Surf. Sci. 75 (2004), 1-68.
Image from www.nanoterra.comAlkanethiolate self-assembled monolayers
Alkanethiolate self-assembled monolayers
Ralph Nuzzo1 and Dave Allara1 demonstrated that alkanethiolate molecules on a gold (Au) surface, formed a ordered monolayer.
1 Nuzzo, R.G., Allara, D.L., J. Am. Chem. Soc. 105 (1983), 4481.
These SAMs have become a ‘model organic surface’ for exploring the chemistries of organic surfaces. The alkanethiolate SAMs assemble into its lowest energy configuration on Au
General formula: T(CH2)n H : Head – substrate specificity: T – surface property : n – chain length
Conductance measurements of multi-chromophoric molecular assemblies
Efforts to scale down electronics to the nanometer regime requires a comprehensive understanding of charge transport through individual molecules.
To achieve this goal, scanning tunneling microscopy can be used to image directly and measure charge transport through individual surface-bound molecules.
Here we utilize alkathiolate SAMs to isolate individual molecules for measurements.
Scanning tunneling microscopy images of (1,2) an octanethiolate SAM; (3) individual porphyrin complexes isolated within the SAM matrix. These images were recorded under high vacuum conditions and at room temperature.
Nanayakkara and Bonnell