It is shown that the SidSi dimers of the reconstructed Si(001) surface can react with the π bonds of unsaturated organic molecules to produce well-defined organic films with novel physical properties. Scanning tunneling microscopy (STM) studies show that the resulting layers are ordered both translationally and rotationally, with the SidSi dimers acting as a template for extending the translational and rotational order from the silicon substrate to the organic film. STM images and infrared spectroscopy experiments show that by using vicinal Si(001) surface having primarily double-height steps, the rotational order of the molecules can be preserved over macroscopic length scales, leading to measurable anisotropy in optical properties. It is proposed that this chemistry may provide a general method for formation of controlled organic films on Si(001) surfaces.

Two methods for patterning surfaces with supported lipid bilayers and immobilized protein are described. First, proteins are used to fabricate corrals for supported lipid bilayers. Poly(dimethylsiloxane) stamps are used to deposit arbitrarily shaped patterns of thin layers of immobilized protein onto glass surfaces. This is followed by vesicle fusion into the regions that are not coated with proteins. Second, supported bilayer membranes are blotted to remove patterned regions of the membrane, 1 and the blotted regions are filled in or caulked with protein from solution. In both cases, the lipid bilayer regions exhibit lateral fluidity, but each region is confined or corralled by the protein. These two methods can be combined and used iteratively to create arrays with increasing lateral complexity in both the fixed protein and mobilesupported membrane regions for biophysical studies or cell-based assays.

Supported lipid bilayers are widely used as model systems due to their robustness. Due to the solid support, the properties of supported lipid bilayers are different from those of freestanding bilayers. In this article, we examine whether different surface treatments affect the properties of supported lipid bilayers. It will be shown that depending on the treatment method, the diffusion of the lipids can be adjusted approximately threefold without altering the composition. Additionally, as the bilayer-support interaction decreases, it becomes easier to form coexisting liquid-ordered and liquid-disordered domains. The physical/chemical alterations that result from the different treatment methods will be discussed.

The reactions of 1,3-dienes with the Si(001) surface have been investigated using scanning tunneling microscopy (STM) and Fourier transform infrared spectroscopy (FTIR), and the relative efficiencies of [2 + 2] and [4 + 2] reactions have been determined. STM and FTIR studies show that the 2,3-dimethyl-1,3-butadiene molecule has two bonding configurations; 80% of the molecules bond via a [4 + 2] reaction involving both alkene groups with the remaining 20% bonding via a [2 + 2] reaction involving only one alkene group. The molecule 1,3-cyclohaxadiene shows three separate bonding configurations in the STM, and the FTIR shows at least four separate peaks in the alkene stretching region. The [4 + 2] product is found to comprise 55% of the surface species, the [2 + 2] product 35%, and an unknown product 10%. The surface temperature is found to have little affect on the product distribution. The formation of multiple products and the lack of temperature effects indicate that the product distribution is controlled primarily by the kinetics of the adsorption process, not by the thermodynamics. Thus, although [4 + 2] reactions are predicted to be more stable, [2 + 2] reactions occur nearly as frequently.

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