Gregory W. Nyce

The Trivalent Neodymium Complex [(C5Me5)3Nd] Is a One-Electron Reductant!

A Se22- complex, Ph3 P, and (C5 Me5 )2 are formed in the reduction of Se=PPh3 by the NdIII complex [(C5 Me5 )3 Nd] [Eq. (a)]. The latter is thus reminiscent of [(C5 Me5 )3 Sm], which, however, appears to be a stronger reductant than [(C5 Me5 )3 Nd]. This suggests that the reductive reactivity of [(C5 Me5 )3 Ln] complexes can be tuned by varying the size of the metal atom.

Structural studies of lanthanide and yttrium metallocene oxides

Abstract Examination of the chemistry of sterically crowded (C5Me4R)3Ln complexes has provided access to a series of [(C5Me4R)2Ln]2(μ-O) complexes: [(C5Me5)2La]2(μ-O), [(C5Me5)2Nd(NC5H4NC4H8)]2(μ-O), [(C5Me4iPr)2Sm]2(μ-O), [(C5Me4Et)2Gd]2(μ-O), and [(C5Me5)2Sm(NC5H5)]2(μ-O). X-ray crystallographic data on these complexes provide information on the effect of metal and cyclopentadienyl ring size on LnO bond distances and LnOLn angles, which vary between 173 and 180° in these complexes.

Structural studies of mono(pentamethylcyclopentadienyl)lanthanide complexes

The mono(pentamethylcyclopentadienyl) lanthanide complexes [(C5Me5)Yb(μ-I)(μ-η 5 : η 5-C5Me5)Yb(C5Me5)]n (1), {[(C5Me5)Sm]3(μ-Cl)4(μ 3-Cl)(μ 3-OH)(THF)}2 (2), {[(C5Me5)Sm]2 (μ-OH)(μ-Cl)4(μ 3-Cl)Mg(THF)2}2 (3), [(C5Me5)2Sm](μ-Cl)6(μ 3-Cl)2(μ 4-Cl)[(C5Me5)Sm]4 (4), {[(C5Me5)Nd]3(μ 3-Cl)4(μ 4-Cl)2(μ 3-O2CPh)2K2(η 6-C7H8)}2 (5), [(C5Me5)Nd(C8H8)]2(μ-dioxane) (6), [(C5Me5)Yb(MeOtBu)]2(μ-η 8 : η 8-C8H8) (7), [(C5Me5)Dy(μ-I)2]3 (8), and [(C5Me5) Tm(MeCN)6]I2 (9), have been identified by X-ray crystallography. 1 is unusual in that it has a μ-η 5 : η 5-C5Me5 ring that generates a local bent metallocene environment around ytterbium. Complexes 2–5 demonstrate the versatility of bridging chlorides in generating a variety of structures for mono(pentamethylcyclopentadienyl) lanthanide halides. Complex 6 shows how dioxane can generate a crystallographically-analyzable complex by bridging two mixed-ligand metallocene units that do not readily crystallize with THF. The structure of 7 shows how methyl tert-butyl ether (MTBE) ligates a lanthanide. Complex 8 is a trimeric cyclopentadienyl lanthanide halide unusual in that it has six bridging halides that roughly define a trigonal prism. Complex 9 constitutes an organometallic example of a lanthanide in which acetonitrile completely displaces iodide counterions.