Synthesis, Characterization, and Reactivity of Dicationic Dihydrogen Complexes of Osmium
- 1 January 1996
- journal article
- Published by American Chemical Society (ACS) in Inorganic Chemistry
- Vol. 35 (15) , 4396-4399
- https://doi.org/10.1021/ic951427n
Abstract
The dicationic Os(II) complex [Os(bpy)(PPh(3))(2)(CO)(H(2))](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 H(2) ligand be in the slow rotation regime. The dicationic complex is a strong acid, indicating that the bound H(2) is substantially activated toward heterolytic cleavage. The H(2) ligand is tightly bound to the metal center, and does not undergo exchange with D(2) over the course of several weeks at room temperature. A related dicationic Os(II) complex, [Os(bpy)(2)(CO)(H(2))](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 H(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.Keywords
This publication has 16 references indexed in Scilit:
- Determination of the Structure of [Os(.eta.2-H2)en2CH3CO2]PF6 by X-ray and Neutron DiffractionJournal of the American Chemical Society, 1994
- Neutron structure and inelastic-neutron-scattering and theoretical studies of molybdenum complex Mo(CO)(H2)[(C6D5)2PC2H4P(C6D5)2]2.cntdot.4.5C6D6, a complex with an extremely low barrier to hydrogen rotation. Implications on the reaction coordinate for H-H cleavage to dihydrideJournal of the American Chemical Society, 1993
- The structures of quartromicins A1, A2, and A3: novel macrocyclic antiviral antibiotics possessing four tetronic acid moietiesJournal of the American Chemical Society, 1991
- Assessment of the "T1 criterion" for distinguishing between classical and nonclassical transition-metal hydrides: hydride relaxation rates in tris(triarylphosphine)osmium tetrahydrides and related polyhydridesJournal of the American Chemical Society, 1991
- Single-crystal x-ray and neutron diffraction studies of an .eta.2-dihydrogen transition-metal complex: trans-[Fe(.eta.2-H2)(H)(PPh2CH2CH2PPh2)2]BPh4Journal of the American Chemical Society, 1989
- Highly reactive dihydrogen complexes of ruthenium and rhenium: facile heterolysis of coordinated dihydrogenOrganometallics, 1989
- Synthetic routes to new polypyridyl complexes of osmium(II)Inorganic Chemistry, 1988
- Vibrational circular dichroism of optically active allenes. Experimental resultsJournal of the American Chemical Society, 1988
- Protonation of hydrido-osmium(II) complexes by trifluoromethanesulfonic acid. Examples of seven-coordination in osmium polypyridyl chemistryInorganic Chemistry, 1987
- Hydrido carbonyl complexes of osmium(II) and ruthenium(II) containing polypyridyl ligandsOrganometallics, 1984