Addition of H 2 to CH 2 Cl 2 solutions of [(diene)Rh(L) 2 ][closo-CB 1 1 H 1 2 ] (diene=norbornadiene, cyclooctadiene, L=PCy 3 , P(OMe) 3 , 1/2dppe) results in the formation of the exo-closo complexes [(PR 3 ) 2 Rh(closo-CB 1 1 H 1 2 )]. These have been characterised in solution by 1 H- and 1 1 B-NMR spectroscopy, and for L=PCy 3 by a single crystal X-ray diffraction study. This suggests that the metal fragment is bound with the cage through the 7,8- and not the 7,12-{BH} vertices. DFT calculations on a model system where L=PMe 3 show that there is only a negligible energy difference between these two isomers (1 kcal mol - 1 ), suggesting that both represent stable structures. The salient spectroscopic markers that indicate an interaction of [closo-CB 1 1 H 1 2 ] - with a metal fragment are discussed and compared across a range of metal complexes. Large upfield shifts in the 1 1 B-NMR spectrum and a small downfield shift of the CH vertex in the 1 H-NMR spectrum are shown to the most reliable indicators of borane interaction in solution.