REDUCTION OF CLAY SURFACE-SORBED ORGANOMETALLICS DURING MEASUREMENT OF X-RAY PHOTOELECTRON-SPECTRA (XPS)

Some organometallic compounds, e.g. Ph3SnCl, react on the surface of t he smectite clay, laponite. Other compounds, e.g. Br3TeC6H4CH= NCH2CH2 N=CHC6H4TeBr3, are sorbed onto the organophilic surface of cetylpyridi nium-ion-exchanged Wyoming bentonite. X-ray photoelectron spectroscopy (XPS) is an appropriate technique with which to examine the nature of the surface-sorbed species; however, it is demonstrated that decompos ition of the organometallic can occur when the clay surface is exposed over a period of time to energetic X-rays. Thus, care must be taken w ith the interpretation of data of which some features may be the resul t of the XPS experiment.