Organolanthanoid Compounds

Abstract

Up to little more than a decade ago organolanthanoid compounds were still a curiosity. Apart from the description of an isolated number of cyclopentadienyl and indenyl derivatives, very few significant contributions had been made to this interesting sector of organometallic chemistry. However, subsequent systematic studies using modern preparative and analytical techniques, together with X-ray single crystal structure determinations, enabled the isolation and characterization of a large number of very interesting homoleptic and heteroleptic compounds in which the lanthanoid is bound to hydrogen, to substituted or unsubstituted cyclopentadienyl groups, to ally1 or alkynyl groups, or even to phosphorus ylides, trimethylsilyl, and carbonylmetal groups. These compounds, which are all extremely sensitive to oxygen and water, open up new possibilities in the field of catalysis and have great potential in organic synthesis-as recent studies with pentamethylcyclopentadienyl derivatives, organolanthanoid(I1) compounds, and hexamethyllanthanoid complexes have already shown.

Scandium, Yttrium & The Lanthanides: Organometallic ChemistryBased in part on the article Scandium, Yttrium & The Lanthanides: Organometallic Chemistry by R. D. Köhn, G. Kociok‐Köhn, & H. Schumann which appeared in theEncyclopedia of Inorganic Chemistry, First Edition.

“…13 The tris(trimethylsilylmethyl)scandium and -yttrium derivatives are thermally unstable. The bulky PhMe 2 SiCH 2 ligand allows the isolation of thermally more robust analogues Ln(CH 2 SiMe 2 Ph) 3 (THF) 2 (M = Sc, Y).…”

“…Yb(CH 2 SiMe 3 ) 3 (THF) 2 and the related neopentyl derivative Yb(CH 2 t Bu) 3 (THF) 2 are formed by the reaction of ytterbium metal with ICH 2 SiMe 3 or neopentyl iodide in THF. 12 X-ray structural analyses of the Sm, Er, Yb, and Lu derivatives show the Sm atom in a fac-octahedral coordination and the heavier lanthanides Er, Yb, and Lu trigonal bipyramidally coordinated with three alkyl ligands in equatorial and two THF molecules in axial positions (equation 2).…”

“…14 Reaction of Ln(CH 2 SiMe 3 ) 3 (THF) 2 (Ln = Y, Lu) with B(C 6 X 5 ) 3 (X = H, F) in the presence of crown ethers yields cationic lanthanide-alkyl complexes, for example, [Ln(CH 2 − (CE = 12-crown-4, n = 1; CE = 15-crown-5 and 18-crown-6, n = 0) (equation 3). 15 The use of four equivalents of LiCH 2 3 have been prepared and structurally characterized recently.…”

“…15 The use of four equivalents of LiCH 2 3 have been prepared and structurally characterized recently.…”

Réduction électrochimique de dérivés carbonylés en milieu non aqueux en présence de EuCl3•6H2O

“…Les complexes de l'europium sont tres utilisks en spectroscopie (17) ou en synthkse organique (18). Dans le cadre du travail que nous avions rCalist avec les sels de chrome et dans un but comparatif, nous avons consacrC cet article 2 l'ttude de la rtduction Clectrochimique de dtrivts carbonylCs en prtsence dleuropium(II) Clectrogtntre.…”