Both 1-amino-3-cyclopentene (ACP) and its protected form $N$-1-tert-butyloxycarbonyl-amino-3-cyclopentene (BACP) were adsorbed at the depassivated Si(100) surface using a hybrid calculation method in a ${\mathrm{Si}}_{197}{\mathrm{H}}_{108}$ cluster. It was found that the ACP molecule can potentially adsorb in at least eight different modes to the surface. The most stable one connects through both its carbon-carbon double-bond and its amine group, forming a bridge-like structure between two dimers, and has an adsorption energy of $-73.9\mathrm{kcal}{\mathrm{mol}}^{-1}$. In what concerns the BACP molecule, it was found that the tert-butyloxycarbonil (tBOC) protecting group does indeed inhibit the reaction of the amine group without affecting energetically the adsorption through the double bond. Its adsorption energy is basically the same as the one for ACP when adsorbed by the same group with both of them having an adsorption energy within $1\mathrm{kcal}{\mathrm{mol}}^{-1}$.

• Received 13 March 2005

DOI:https://doi.org/10.1103/PhysRevB.72.075445