Synthesis, characterization, and reactivity of dicationic dihydrogen complexes of osmium
- Univ. of Washington, Seattle, WA (United States)
The dicationic Os(II) complex [Os(bpy)(PPh{sub 3}){sub 2}(CO)(H{sub 2})]{sup 2+} has been prepared as the triflate salt. The presence of a bound dihydrogen ligand is indicated by a short T{sub 1} minimum value consistent with an H-H distance of 1.05 {angstrom}. In the partially deuterated derivative J{sub 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 {angstrom}, which requires that the bound H{sub 2} ligand be in the slow rotation regime. The dicationic complex is a strong acid, indicating that the bound H{sub 2} is substantially activated toward heterolytic cleavage. The H{sub 2} ligand is tightly bound to the metal center, and does not undergo exchange with D{sub 2} over the course of several weeks at room temperature. A related dicationic Os(II) complex, [Os(bpy){sub 2}(CO)(H{sub 2})]{sup 2+}, has also been prepared. A short T{sub 1} minimum value and a J{sub HD} value of 29.0 Hz in the partially deuterated derivative is most consistent with a H-H distance of 0.99 {angstrom}. The bound H{sub 2} ligand of this complex is significantly less activated toward heterolytic cleavage and is stable in solution for less than a day at room temperature.
- OSTI ID:
- 476845
- Journal Information:
- Inorganic Chemistry, Journal Name: Inorganic Chemistry Journal Issue: 15 Vol. 35; ISSN 0020-1669; ISSN INOCAJ
- Country of Publication:
- United States
- Language:
- English
Similar Records
Determination of the structure of [Os([eta][sup 2]-H[sub 2])en[sub 2]CH[sub 3]CO[sub 2]]PF[sub 6] by X-ray and neutron diffraction
Studies of the protonation and oxidation of sulfido ligands in dinuclear molybdenum complexes