碘乙月青在Cu(100)表面上的熱化學研究

Temperature-programmed reaction/desorption (TPR/D) and reflection absorption infrared spectroscopy (RAIRS) have been employed to investigate the thermal reactions and intermediates of ICH2CN on Cu(100) in an ultra-high vacuum system. The TPR/D study shows the evolution of reaction products of CH3CN, HCN, H2 and C2N2. After the desorption of the products, atomic C, N and I are left on the surface, examined by Auger electron spectroscopy. The RAIRS investigation shows that -CH2CN is generated from ICH2CN dissociative adsorption on Cu(100) at 180 K. A part of -CH2CN molecules transforms to -CHCN at 240 K. Between 240-300K,-CH2CN and -CHCN is coexist on the surface. Theoretical calculation predicts that -CH2CN is most likely to be adsorbed at atop sites on Cu(100). -CH2CN generated at low coverages has its C-C-N backbone approximately parallel to the surface. At higher coverages, the backbone tilts away from the surfaces.