CHEMISTRY OF CYCLIC OLEFINS AND POLYENES ON NICKEL AND PLATINUM SURFACES

Results of ultrahigh vacuum studies of C/sub 4/-C/sub 8/ cyclic olefins and polyene chemisorption on Ni and Pt surfaces are presented. A mechanism is proposed for the novel surface mediated conversions of cycloheptatriene and norbornadiene to benzene. Studies of adsorption and thermal desorption of norbornadiene-7-d/sub 1/ on Pt(111) and Pt(100) indicated that there is no deuterium in the benzene produced on Pt(111), but that produced on Pt(100) contained approx. 15 to 20% C/sub 6/H/sub 5/D. An exchange process between C/sub 6/H/sub 6/ and D atoms on Pt(100) has been established but not for Pt(111). (BLM)