Ethylidyne vibrational spectra

Figure 6. a) SFG spectrum of the Pt(lll) surface during ethylene hydrogenation with 100 Torr Hj, 35 Torr 615 Torr He at 295 K b) The vibrational spectrum of the same system after the evacuation of the reaction cell c) SFG spectrum under the same conditions as a), but on a surface which was pre-covered in UHV with 0.52 monolayers of ethylidyne. 

Fig. 22. High-resolution electron energy loss vibrational spectrum of ethylidyne (CCHj) and ethylidyne-rfj on Rh(lll) the stable, room temperature, chemisorbed structure for ethylene...

When either the di-a-bonded or the r-coordinated species is warmed to room temperature, ethylidyne (=C - CH3) is generated this surface compound is rather stable since the anchored carbon is bonded to three different metal atoms. The HREEL spectrum of chemisorbed ethylidyne is characterized by vibrational modes of Csv symmetry the C-H stretch is at 2900cm (360meV), the CH3 wag and C-C stretch within the 1400 (174meV) to 1800cm (223 meV) interval, and the M-C stretch near 425cm ... 

---