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 exter nal port of a BOMEM DA3 FTIR instrument is used for in situ spectrosco py on ZnSe surfaces in the range 600-4000 cm(-1). ATR-IR studies on si lylating reactions had been restricted to the 1400-4000 cm(-1) range b ecause of the strong absorption bands corresponding to nu(as)(Si-O-Si) and other limiting factors. Noteworthy spectra of growing very thin w ater films are observed. HSiCl3 is used to form polysiloxane films bea ring 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 band s at 910 and 880 cm(-1) are shown to be useful to investigate the reac tion. The Si-H groups at the surface are reacted with Co-2(CO)(8) to f orm (-O)(3)Si-Co(CO)(4) complexes; this results in a decrease of the d elta(Si-H) mode at 820 cm(-1). The final spectrum compares well with t hat of [Co(CO)(4)(H7Si8O12)] in the range of the carbonyl vibrations.