Silicon surfaces as electron acceptors: Dative bonding of amines with Si(001) and Si(111) surfaces

TitleSilicon surfaces as electron acceptors: Dative bonding of amines with Si(001) and Si(111) surfaces
Publication TypeJournal Article
Year of Publication2001
AuthorsCao, XP, Hamers, RJ
JournalJournal of the American Chemical Society
Volume123
Pagination10988-10996
Date PublishedNov
Type of ArticleArticle
ISBN Number0002-7863
Accession NumberISI:000172049200025
Keywordsspectroscopy
Abstract

The bonding of them trimethylamine (TMA) and dimethylamine (DMA) with crystalline silicon surfaces has been investigated using X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy, and density-functional computational methods. XPS spectra show that TMA forms stable dative-bonded adducts on both Si(001) and Si(111) surfaces that are characterized by very high N(1s) binding energies of 402.2 eV on Si(001) and 402.4 eV on Si(111). The highly ionic nature of these adducts is further evidenced by comparison with other charge-transfer complexes and through computational chemistry studies. The ability to form these highly ionic charge-transfer complexes between TMA and silicon surfaces stems from the ability to delocalize the donated electron density between different types of chemically distinct atoms within the surface unit cells. Corresponding studies of DMA on Si(001) show only dissociative adsorption via cleavage of the N-H bond. These results show that the unique geometric structures present on silicon surfaces permit silicon atoms to act as excellent electron acceptors.

URL<Go to ISI>://000172049200025