Dedicated to Professor John R. Shapley on the occasion of his 60th birthday Considerable research effort has been devoted to preparing a variety of [60]fullerene-based (C 60 ) derivatives because of their potential application in the optical, magnetic, electronic, catalytic, and biological areas of materials science. [1] In particular, exohedral metallofullerene chemistry has been intensively studied to investigate new chemical and physical properties of metal-C 60 coordination. Of special importance are studies on the reactivity and electrochemical properties of these complexes that can lead ultimately to new electronic nanomaterials and nanodevices. [2] Various bonding interactions between metals and C 60 have been reported, such as h 2 , [3] m-h 2 :h 2 , [4] and h 5 types [5] and, particularly, m 3 -h 2 :h 2 :h 2 , m 3h 1 :h 2 :h 1 , m 3 -h 1 :h 1 :h 2 , and m 4 -h 1 :h 1 :h 2 :h 2 modes for metal clusters. [2a, 6] The C 60 surface can accommodate up to six separate single metal centers through h 2 interactions, [3b] but only 1:1 adducts of C 60 and metal clusters have been reported to date. [2a, 7] However, 2:1 adducts (C 60 sandwich complexes) are known for {Ir 4 } and {Rh 6 } clusters. [6, 8] Herein we report the synthesis, characterization, and theoretical studies of three structural isomers of the title complex, [Os 3 (CO) 6 (PMe 3 ) 3 ](m 3h 2 :h 2 :h 2 -C 60 )[Re 3 (m-H) 3 (CO) 9 ]-unprecedented 1:2 adducts in which C 60 is bound to multiple cluster moieties.