کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5425200 | 1395850 | 2007 | 9 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Reaction of acetonitrile with the silicon(0 0 1) surface: A combined XPS and FTIR study Reaction of acetonitrile with the silicon(0 0 1) surface: A combined XPS and FTIR study](/preview/png/5425200.png)
The adsorption of acetonitrile on the Si(0Â 0Â 1) surface has been investigated using X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR). XPS and FTIR spectra indicate that adsorbed acetonitrile forms two correlated binding configurations, a CN species with a strong FTIR absorption at 1540Â cmâ1 and a CCN (ketenimine) species that has a very strong FTIR absorption at 1952Â cmâ1. The CCN FTIR peak at 1952Â cmâ1 shows a striking polarization dependence, with the infrared transition dipole almost entirely in the plane of the sample and parallel to the SiSi dimer axis. Our data suggests that the primary CCN structure results from cleavage of two C-H bonds, forming a structure in which the N and terminal C atom are both linked to the surface. Temperature-dependent experiments help to elucidate the complicated reaction mechanism for acetonitrile adsorbing onto the Si(0Â 0Â 1) surface. Dosing at higher temperature increases the amount of CCN relative to CN species while heating leads to direct transformation of the CN to the CCN species. Our results indicate that previous studies, which considered only products formed by cleavage of a single C-H bond, have misidentified the primary ketenimine product. A reinterpretation of the earlier results, combined with data presented here, sheds new light onto the products and mechanism of interaction of acetonitrile with Si(0Â 0Â 1).
Journal: Surface Science - Volume 601, Issue 4, 15 February 2007, Pages 945-953