Adsorption of protected and unprotected amino-cyclopentene at the Si(100) surface modeled with a hybrid quantum mechanical cluster technique

Abstract

Both 1-amino-3-cyclopentene ͑ACP͒ and its protected form N-1-tert-butyloxycarbonylamino-3-cyclopentene ͑BACP͒ were adsorbed at the depassivated Si͑100͒ surface using a hybrid calculation method in a Si 197 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 kcal mol −1. In what concerns the BACP molecule, it was found that the tert-butyloxycarbonil ͑tBOC͒ 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 kcal mol −1 .

A theoretical study of ethylene, cyclopentene and 1-amino-3-cyclopentene adsorption on the silicon surface

“…Previous findings, obtained using GOs as well as PWs, slab or cluster models, are summarized in tables 5 and 6 for C 2 H 4 and C 5 H 8 respectively; some of these results had also been collected in [29]. Reference [33] also reports an adsorption energy for C 5 H 7 NH 2 of −36.1 kcal mol −1 (−1.57 eV) calculated within a cluster model using GOs and a hybrid DFT-semiempirical method. In table 5 an experimental measurement of the adsorption energy is reported as well.…”

Amino Acid Adsorption on the Si(100) Surface: The Case of Glycine

“…Given the overriding importance of the Si(100) surface, it is not surprising that there has been a marked increase in the number of experimental studies investigating the reactions of organics with this surface. − Despite this interest, only recently have detailed theoretical investigations of the organics on Si(100) started to emerge. − For example, several groups have investigated the [2 + 2] or [4 + 2] cycloaddition reactions between CO, CC, or NC in organic molecules and Si dimers to form four- or six-member rings. − ,,, For instance, investigations show that when benzaldehyde is attached to the Si(100) surface the CO group has a stronger binding with the Si dimer than with the CC group, leaving its phenyl ring skeleton intact, which retains its conjugated π-bonding after adsorption. Similar results are obtained with acetophenone adsorption .…”