Amino-Terminated Organic Monolayers on Hydrogen-Terminated Silicon Surfaces

Abstract

A new approach has been developed to prepare amino-terminated monolayers on hydrogen-terminated silicon surfaces. This two-step procedure is the first method that provides direct control over the surface density of the amino groups. First, a mixed monolayer of a protected ω-amino-1-alkene and a nonfunctional 1-alkene is prepared on a H-terminated Si surface, using either phthalimide or acetamide as NH2-protecting groups. Subsequent removal of the protective groups generates the covalently attached NH2-terminated monolayer, as evidenced from water contact angle measurements, IR spectroscopy, and X-ray photoelectron spectroscopy. Both protecting groups have their own advantages: use of the phthalimide moiety is synthetically very convenient; the relatively small acetamide moiety can be used to prepare monolayers with high densities (>50%) of amine groups. The reactivity of the amine groups has been confirmed by further modification of the monolayers.

Wet chemical routes to the assembly of organic monolayers on silicon surfaces via the formation of Si–C bonds: surface preparation, passivation and functionalization

“…1). [75][76][77][78] Hydrogenated silicon surfaces are attractive to work with because of their ease of preparation, 78 their relative stability in air 79,80 and during brief water ring procedures, 31,76 and their lack of appreciable reactivity toward a range of common solvents (including acetonitrile, 81 diethyl ether, 46 chlorobenzene, 82 hexane, 83 toluene 84 and mesitylene 85,86 preparation of covalent organic layers by wet chemical methods. 87 Notable exceptions to the typically straightforward conditions are [2+2] and [4+2] cycloaddition reactions under 'dry' UHV conditions.…”

Sensing Immobilized Molecules of Streptavidin on a Silicon Surface by Maldi-Tof Mass Spectrometry and Fluorescence Microscopy

“…All glassware for distillations, re-crystallizations, and monolayer preparations was cleaned with distilled solvents. Other details have been described previosly 8,23,24,25 . Si (111), n-type wafers were purchased from SILTRONIX, 5-10 Ohm/cm.…”

Influences of Doping and Crystal Orientation on Surface Roughening upon Alcohol Grafting onto Silicon Hydride

“…To begin with, it is important to consider the issue of steric hindrance for Sieval et al simply stated that a full passivation cannot be attained due to the proximity of the silicon adatoms [11,12]. It was also increasingly clear that even at temperatures above 150 • C, the nominal silicon hydride homolysis may not be the initiating process on silicon surfaces as described by Coletti et al and there might be the contention of surface silicon dimerization, especially in ultra high vacuum conditions [13].…”