On Pt(111) at 110 K, 1-iodopropane, C3H7I, adsorbs molecularly, but for dos
es below 1.7 x 10(14) molecules cm(-2), only H-2 and I appear in thermal de
sorption. C-I bond cleavage occurs between 160 and 220 K, forming adsorbed
n-propyl, C(a)H2CH2CH3, and atomic iodine, based on temperature-programmed
desorption (TPD), high-resolution electron energy loss spectroscopy (HREELS
), and X-ray photoelectron spectroscopy (XPS). n-Propyl undergoes beta-hydr
ide elimination forming propylene, with desorption peaks at 185 and 240 K.
At 240 K, hydrogenation to propane also occurs. Some di-sigma bonded propyl
ene, C(a)H2C(a)HCH3, remains at 240 K and it rearranges to propylidyne near
300 K. Atomic H, bond to Pt, recombines and desorbs at ca. 260 K. Further
desorption of H-2 is limited by C-H bond breaking and occurs over a broad t
emperature range with local maxima at ca. 280, 320, and 420 K, typical of p
ropylidyne fragments on Pt. Atomic iodine desorbs in a broad feature at 825
K.