Thermal and photoinduced covalent attachment of 3-Chloro-1-propanol on Si(100)-2× 1

Abstract

3-Chloro-1-propanol (HO-CH2-CH2-CH2-Cl) covalently binds onto Si(100)-2× 1 through the thermal dissociation of the OH group to form Si-O-CH2-CH2-CH2-Cl surface intermediates, evidenced by the appearance of the Si-H stretching mode (2110 cm-1) and the retention of C-Cl stretching mode (654 cm-1) in the high-resolution electron energy loss spectroscopy (HREELS) spectrum of chemisorbed 3-chloro-1-propanol molecules and the chemical downshift of O1s binding energy (BE) in the X-ray photoelectron spectroscopy (XPS) study. The C-Cl bonds in the chemisorbed 3-chloro-1-propanol can be cleaved upon 193 nm irradiation, resulting in Si-O-CH2CH2CH 2-CH2CH2CH2-O-Si through lateral diradical coupling. Upon covering the chemisorbed 3-chloro-1-propanol with physisorbed molecules, photoinduced diradical coupling between physisorbed and chemisorbed molecules was also evidenced, achieving the secondary attachment of 3-chloro-1-propanol on the Si surface and forming Si-O-CH2CH 2CH2-CH2CH2CH2-OH. © 2010 American Chemical Society.