THE INFRARED-SPECTRUM OF CYCLOHEXANE ADSORBED ON PT(111)

The reflection-absorption infrared spectrum of cyclohexane adsorbed on Pt(111) has been recorded using a Fourier Transform spectrometer. The spectrum at 150 K shows the broad, low-frequency CH stretching band previously revealed by electron energy loss spectroscopy and also three sharper bands attributed to vibrational modes involving the relatively unperturbed hydrogens. At 95 K a second adsorbed phase is formed in which the perturbation of the molecule is reduced. Continued exposure leads to multilayer formation. Spectra of adsorbed monolayers of the related compounds n-hexane, cyclopentane and 2,2-dimethylpropane (neopentane) showed much less evidence for perturbation of CH bonds. © 1990.