In situ attenuated total reflection FTIR investigations of H2O,HSiCl3, and Co-2(CO)(8) on ZnSe in the range 600-4000 cm(-1)

A new attenuated total reflection (ATR)-IR set-up attached to an external port of a BOMEM DA3 FTIR instrument is used for in situ spectroscopy on ZnSe surfaces in the range 600-4000 cm(-1). ATR-IR studies on silylating reactions had been restricted to the 1400-4000 cm(-1) range because of the strong absorption bands corresponding to nu(as)(Si-O-Si) and other limiting factors. Noteworthy spectra of growing very thin water films are observed. HSiCl3 is used to form polysiloxane films bearing Si-H units at the surface. Si-H bending at 802 and 820 cm(-1), nu(SiCl3) at 596 cm(-1), Si-O-Si modes at 1150 and 1067 cm(-1), and bands at 910 and 880 cm(-1) are shown to be useful to investigate the reaction. The Si-H groups at the surface are reacted with Co-2(CO)(8) to form (-O)(3)Si-Co(CO)(4) complexes; this results in a decrease of the delta(Si-H) mode at 820 cm(-1). The final spectrum compares well with that of [Co(CO)(4)(H7Si8O12)] in the range of the carbonyl vibrations.