Adsorption of acetonitrile and acrylonitrile on Si()-2×1 at room temperature studied by synchrotron radiation photoemission and NEXAFS spectroscopies

Reaction of acetonitrile with the silicon(001) surface: A combined XPS and FTIR study

“…Previous studies of acetonitrile interacting with Si(0 0 1) have identified the four-member ring shown in Fig. 5a as one product of acetonitrile adsorption [15,18,21]. While this structure is formally identical to the product of a [2 + 2] cycloaddition reaction of the Si@Si dimer with the C"N bond, theoretical studies have reported that it likely forms through a dative-bonded intermediate [23,36], in agreement with studies of analogous reactions in the organic chemistry literature [37].…”

“…Several studies indicate that nitriles react with Si(0 0 1) [13][14][15][16][17][18][19][20][21][22], yet mechanistic details for the simplest nitrile systems remain unclear due to the complication of several products being formed [13][14][15][16][19][20][21]23]. In particular, it has been shown that acetonitrile forms several products at room temperature although this is the functionally simplest nitrile system in terms of available reactive groups [15,[19][20][21]23]. In this paper, we have investigated the chemistry of acetonitrile on the Si(0 0 1) surface to gain a more complete understanding of the products that are formed and to better sort out mechanistic details of this complicated reaction.…”

A theoretical study of acrylonitrile adsorption on Si(001)

“…Acrylonitrile (CH 2 = CH − C ≡ N ) is a molecule with two of the most important building blocks for many organic molecules: the vinyl and cyano groups, and has a rich chemistry (for an extensive discussion see [1] and references therein). The absorption of acrylonitrile on Si(001) has been recently studied both from the experimental [1,2] and theoretical points of view [1]. While Tao et al [1], from a HighResolution Electron Energy Loss (HREEL) study of Si(001) exposed to acrylonitrile at 110 K and first-principles calculations of two possible absorption geometries, concluded that the absence of the C ≡ N peak with the concurrent emergence of the C = N peak is the direct evidence for the participation of the cyano group in the interaction with surface silicon dimers; Bournel et al [2], from a synchroton Photoemission Spectroscopy (PES) study and their Near Edge X-ray Absorption Fine Structure (NEXAFS) N and C Kedges spectra, showed that their results are not in agreement with the above proposed mechanism.…”

“…The absorption of acrylonitrile on Si(001) has been recently studied both from the experimental [1,2] and theoretical points of view [1]. While Tao et al [1], from a HighResolution Electron Energy Loss (HREEL) study of Si(001) exposed to acrylonitrile at 110 K and first-principles calculations of two possible absorption geometries, concluded that the absence of the C ≡ N peak with the concurrent emergence of the C = N peak is the direct evidence for the participation of the cyano group in the interaction with surface silicon dimers; Bournel et al [2], from a synchroton Photoemission Spectroscopy (PES) study and their Near Edge X-ray Absorption Fine Structure (NEXAFS) N and C Kedges spectra, showed that their results are not in agreement with the above proposed mechanism. They observed features corresponding to both fragments of the molecule and to the presence of Si-C and Si-N bonds, and also concluded that a large fraction of this molecule (of C s symmetry in the gas phase) is absorbed with the molecular plane parallel to the substrate plane.…”

“…They observed features corresponding to both fragments of the molecule and to the presence of Si-C and Si-N bonds, and also concluded that a large fraction of this molecule (of C s symmetry in the gas phase) is absorbed with the molecular plane parallel to the substrate plane. They suggested that only a CN axis "tilted" with respect to the silicon surface could explain the unpolarized nature of the observed π * (2) transition [2].…”