ADDITIONS OF CYCLO-(AR2SI)(4) AND (AR2GE)(4) TO C-60

The photochemical reaction of cyclotetrasilane 1a with C-60 afforded s table 1:1 adducts 2a and 3a; the latter was obtained from a rearrangem ent of the cyclotetrasilane unit. Similarly, cyclotetragermane 1c gave 2c and the rearranged product 3c. In the case of cyclotetrasilane 1b, only the rearranged product 3b was obtained in high yield. The struct ures of all compounds were determined by spectroscopic methods, includ ing Si-29-H-1 HMBC hetero nuclear shift correlation experiments.