RAIRS methyl groups

We turn next to the information provided by the band position data. Table III shows that the surface methyl group can be characterized by bands in six regions three of them are always observed in on-specular VEELS (and in principle in RAIRS) and three virtually always in off-specular and sometimes also on-specular VEELS, as discussed earlier. Their values exhibit a metal dependence, as shown in Table IV, where average values are quoted, except that in the case of pCH3 s on Pt(lll), we have made use of a particularly accurate and consistent RAIR value. 

RAIRS studies of propyne on Ni(l 11) and on Cu(l 10) showed that addition of the methyl group made little difference to the interaction of the triple bond to the surface, the adsorbed states being well described by structure 15 in Table 4.2. 

A VEEL spectrum of the species formed by the decomposition of tert-butyl (2-methyl-2-propyl) chloride and bromide on Cu(100) at 185 and 120 K, respectively (193), shows intensity anomalies similar to those discussed for 2-propyl groups when interpreted in terms of surface terf-butyl groups. Further RAIRS and VEELS work is required. 

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