Reaction of the bis(dihydrogen) ruthenium complex RuH 2 (H 2 ) 2 (PCy 3 ) 2 (1) with an excess of 9-borabicyclononane yields Ru[(μ-H) 2 BC 8 H 1 4 ] 2 (PCy 3 ) (6) and the phosphine adduct PCy 3 .HBC 8 H 1 4 . The new complex is characterized by NMR spectroscopy and X-ray diffraction. New X-ray data on 9-BBN dimer, from a measurement at 180 K, are also reported. DFT calculations (B3LYP) on Ru[(μ-H) 2 BC 8 H 1 4 ] 2 (PMe 3 ) (7), the PMe 3 analogue of 6, confirm the ruthenium (II) formulation with two dihydroborate ligands. The data obtained using PH 3 or PMe 3 as models for PCy 3 in PR 3 .HBC 8 H 1 4 are also discussed.