Synthesis of the mixed ligand complexes (C5Me 5)(C5Me4H)2Ln (Ln = Lu, Y) for comparison with (C5Me5)2(C5Me 4H)Ln to evaluate details of steric effects on reductive reactivity has revealed that (C5Me5)3-x(C 5Me4H)xLn complexes can reduce dinitrogen to (NN)2-. (C5Me5)(C5Me 4H)2Lu reacts with N2 to form [(C 5Me5)(C5Me4H)Lu]2(μ- η2:η2-N2), (C5Me 5)2(C5Me4H)Y reduces N2 to [(C5Me5)2Y]2(μ- η2:η2-N2), and (C5Me 4H)3Sc converts N2 to [(C5Me 4H)2Sc]2(μ-η2: η2-N2). Exclusive (C5Me4H) 1- loss occurs in each case with formation of (C5Me 4H)2 as the byproduct. (C5Me5) 2, the signature byproduct of sterically induced reduction reactions, is not observed. Since these complexes do not exhibit unusual steric parameters and since the more crowded (C5Me5)2(C 5Me4H)Lu and (C5Me5)3Y do not display analogous reactivity, these reactions do not appear to be sterically induced reductions and suggest a new type of ligand-based reduction pathway involving (C5Me4H)1-.
|Original language||English (US)|
|Number of pages||5|
|State||Published - Oct 1 2011|