The reaction of [Os₃Rh(μ-H)₃(CO)₁₂] with an excess amount of 4-vinylphenol (as hydride acceptor) in refluxing m-xylene, chlorobenzene or benzene yielded the three new clusters [Os₅Rh₂(μ-CO){η⁶-C₆H₄(CH₃)₂}(CO)₁₆] 1, [Os₅Rh₂(μ-CO)(η⁶-C₆H₅Cl)(CO)₁₆] 2 and [Os₅Rh₂(μ-CO)(η⁶-C₆H₆)(CO)₁₆] 3. The treatment of [Os₃Rh(μ-H)₃(CO)₁₂] in refluxing toluene with an excess amount of 4-vinylphenol afforded a new complex, [Os₄Rh(μ-H)(η⁶-C₆H₅CH₃)(CO)₁₂] 4, which was isolated as a brown complex in 20% yield together with two known compounds, [Os₅Rh₂(η⁶-C₆H₅CH₃)(μ-CO)(CO)₁₆] in 10% yield and [Os₃Rh₄(μ₃-η¹:η¹:η¹-C₆H₅CH₃) (CO)₁₃] in 5% yield. Complexes 1–4 were fully characterized by IR, ¹H NMR spectroscopy, mass spectroscopy, elemental analysis and X-ray crystallography. The molecular structures of compounds 1–3 are isomorphous, and only differ in the arene-derivatives that attach to the same metal core. Their metal cores can be viewed as a monocapped octahedral, in which an osmium atom caps one of the Os–Os–Os triangular faces of the Os₄Rh₂ metal framework. Complex 4 has a trigonal-bipyramidal metal core with a C₆H₅Me ligand that is terminally bound to the Rh atom that lies in the trigonal plane of the metal core. The hydrogenation of [Os₅Rh₂(η⁶-C₆H₅CH₃)(μ-CO)(CO)₁₆] with [Os₃(μ-H)₂(CO)₁₀] in chloroform under reflux resulted in two hydrogen-rich compounds: [Os₇Rh₃(μ-H)₁₁(CO)₂₃] 5 and [Os₅Rh₃Cl(μ-H)₈(CO)₁₈] 6, both in moderate yields. The reaction of [Os₅Rh₂(η⁶-C₆H₅CH₃)(μ-CO)(CO)₁₆] with hydrogen in refluxing chloroform yielded a new cluster compound, [Os₅Rh(μ-H)₅(CO)₁₈] 7, in 20% yield, together with a known osmium–rhodium cluster, [Os₆Rh(μ-H)₇(μ-CO)(CO)₁₈], as a major compound. Clusters 5, 6 and 7 have been fully characterized by both spectroscopic and crystallographic methods. Additionally, a deuterium-exchange experiment was performed on [Os₇Rh₃(μ-H)₁₁(CO)₂₃] 5 and [Os₅Rh₃Cl(μ-H)₈ (CO)₁₈] 6. Both the compounds proved to be able to exchange the H atom with D in the presence of D₂SO₄, and the absence of the hydride signal in the ¹H NMR spectrum is consistent with this. Therefore, clusters 5 and 6 may serve as appropriate new hydrogen storage models.