Details

Autor(en) / Beteiligte

• Heinekey, D. Michael
• Luther, Thomas A

Titel

Synthesis, Characterization, and Reactivity of Dicationic Dihydrogen Complexes of Osmium

Ist Teil von

• Inorganic chemistry, 1996-07, Vol.35 (15), p.4396-4399

Ort / Verlag

United States: American Chemical Society

Erscheinungsjahr

1996

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The dicationic Os(II) complex [Os(bpy)(PPh3)2(CO)(H2)]2+ has been prepared as the triflate salt. The presence of a bound dihydrogen ligand is indicated by a short T 1 minimum value consistent with an H−H distance of 1.05 Å. In the partially deuterated derivative J HD = 25.5 Hz was observed. By comparison to other structurally characterized complexes, the observed H−D coupling is most consistent with a H−H distance greater than 1 Å, which requires that the bound H2 ligand be in the slow rotation regime. The dicationic complex is a strong acid, indicating that the bound H2 is substantially activated toward heterolytic cleavage. The H2 ligand is tightly bound to the metal center, and does not undergo exchange with D2 over the course of several weeks at room temperature. A related dicationic Os(II) complex, [Os(bpy)2(CO)(H2)]2+, has also been prepared. A short T 1 minimum value and a J HD value of 29.0 Hz in the partially deuterated derivative is most consistent with a H−H distance of 0.99 Å. The bound H2 ligand of this complex is significantly less activated toward heterolytic cleavage and is stable in solution for less than a day at room temperature.