SUBSTITUTION ON METALLABORANES AT BORON - SYNTHESES OF -1-X-[2,3,4-(ETA(5)-C(5)ME(5))(3)(MU-H)(2)CO3B2H], X=CL AND OH, AND 5-CL-2-[2,3,4-(ETA(5)-C(5)ME(5))(3)(MU-H)(2)CO3B2] FROM LOSO-[2,3,4-(ETA(5)-C(5)ME(5))(3)(MU-H)(2)CO3B2H2]

The reaction of oso-[2,3,4-(eta(5)-C(5)Me(5))(3)(mu-H)(2)Co3B2H2], 1, With metal chlorides results in the formation of either 1-Cl-[2,3,4-(e ta(5)-C(5)Me(5))(3)(mu-H)(2)Co3B2H], 2, or -Cl-2-[2,3,4-(eta(5)-C(5)Me (5))(3)(mu-H)(2)Co3B2], 3, depending on chlorination reagent. Hydrolys is of 1, yields 1-OH-[2,3,4-(eta(5)-C(5)Me(5))(3)(mu-H)(2)Co3B2H], 4. Isolated yields of 2 and 4 are modest to good, and all compounds have been characterized spectroscopically as simple substitution derivative s of 1. The substituent effects have been probed by B-11 NMR measureme nts and compared with those for other substituted borane and metallabo rane clusters. The observation of an enhanced antipodal effect shows t hat 1 possesses a characteristic property of a five-atom close cage su ggesting delocalized cluster bonding that includes both the boron and metal centers.