Covalent attachment of acetonitrile on Si(100) through Si–C and Si–N linkages

Abstract

The covalent binding and adsorption states of acetonitrile on Si(100) have been investigated using temperature programmed desorption (TPD), x-ray photoelectron spectroscopy (XPS), high-resolution electron energy loss spectroscopy (HREELS), and density function theory (DFT) calculation. XPS and HREELS results show that acetonitrile chemisorbs on Si(100) in a side-on di-σ binding configuration, forming Si–C and Si–N σ bonds. TPD measurements reveal the presence of two desorption states, β1 and β2 with desorption energies of 29.8 and 24.6 kcal mol−1, respectively. Based on DFT calculations, the β1 state is possibly assigned to di-σ bonded acetonitrile on top of a dimer and/or in an in-row bridging chemisorption, while the β2 state is related to acetonitrile bonded in a cross-row bridging configuration.