INOR 290 |
| Recent developments in lanthanide reduction chemistry have shown how the chemistry traditionally available only to the divalent lanthanide ions can be extended to all the metals in the series. This can be accomplished via sterically induced reduction involving (C5Me5)3Ln complexes and by the LnZ3/K and LnZ2Z'/K reduction systems in which Z = (C5Me5)1-, (C5Me4H)1-, and [N(SiMe3)2]1- and Z' = [BPh4]1-. We report here a new option that is complementary to these methods and allows facile entry into reductive chemistry with analogous complexes of both the largest and the smallest lanthanides, La and Lu, respectively. With this pair of metals, size optimization of the reductive chemistry can be evaluated with the extremes in the series and with diamagnetic products. The trivalent lanthanide dinitrogen complexes, [(C5Me4R)2Ln(THF)]2(μ-η2:η2-N2) (R = H, Me), can mimic the Sm2+ reduction chemistry of (C5Me5)2Sm in reactions with substrates such as phenazine, anthracene, CO2, and CO. These substrates undergo two-electron reduction chemistry by the bimetallic trivalent lanthanide complexes without requiring an alkali metal, steric crowding, or an isolable divalent state. Variations in the phenazine reduction products as a function of size will be discussed as well as the unusual nature of the reductive homologation of CO to the ketene carboxylate, (O2CCCO)2-, in which one CO bond has been completely cleaved. |
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Lanthanides and Actinides
7:00 PM-10:00 PM, Sunday, 10 September 2006 Moscone Center -- Hall D, Poster
Division of Inorganic Chemistry |