Three monoalkoxy-substituted nido-platinaboranes: [(PPh₃)₂PtB₁₀H₁₁-8-(OCH₃)], [(PPh₃)₂PtB₁₀H₁₁-8-{OCH(CH₃)₂}] and [(PPh₃)₂PtB₁₀H₁₀-9-{OCH(CH₃)₂}]

Each of the title compounds, 8-methoxy-7,7-bis­(tri­phenyl­phosphine-P)-8,9:10,11-di-μH-7-platina-nido-undecaborane di­chloro­methane hemisolvate, [Pt(CH₁₄B₁₀O)(C₁₈H₁₅P)₂]·0.5CH₂Cl₂, (I), 8-isopropoxy-7,7-bis­(tri­phenyl­phosphine-P)-8,9:10,11-di-μH-7-platina-nido-undecaborane di­chloro­methane solvate, [Pt(C₃H₁₈B₁₀O)(C₁₈H₁₅P)₂]·CH₂Cl₂, (II), and 9-isopropoxy-7,7-bis­(tri­phenyl­phosphine-P)-8,9:10,11-di-μH-7-platina-nido-undecaborane di­chloro­methane solvate, [Pt(C₃H₁₈B₁₀O)(C₁₈H₁₅P)₂]·CH₂Cl₂, (III), has an 11-vertex nido polyhedral skeleton, with the 7-platinum centre ligating to two exo-polyhedral PPh₃ groups and an alkoxy-substituted polyhedral borane ligand. Compounds (II) and (III) are isomers. The Pt—B distances are in the range 2.214 (7)–2.303 (7) Å for (I), 2.178 (16)–2.326 (16) Å for (II) and 2.205 (6)–2.327 (6) Å for (III).