Andrea L. Wayda

Reactivity of lanthanide carbon σ bonds: Alkyllanthanide complexes as synthetic precursors to lanthanide alkynides

Abstract A general, halide-free synthesis of σ-bonded organolanthanides is demonstrated by the reaction of terminal alkynes with LiLn(t-C 4 H 9 ) 4 (THF) 4 to form a new series of homoleptic lanthanide alkynide complexes, LiLn(CCR) 4 (THF), and by the synthesis of [(C 5 H 5 ) 2 LnCCR] 2 from [(C 5 H 5 ) 2 LnCH 3 ] 2 .

Organometallic Chemistry of the Lanthanides under Reductive Conditions

Although the lanthanide metals comprise nearly 20% of the stable metallic elements in the periodic system, relatively little use has been made of these elements in catalytic reactions (1). Homogeneous catalyses involving the lanthanide metals are particularly rare (2). This situation does not arise because the lanthanides are rare elements, for lanthanum, cerium, praseodymium, and neodymium, are as common as lead, and even the rarest lanthanide, thulium, is more common than mercury (3). It is more likely that the limited use of the lanthanide metals in catalytic sequences is a reflection of the limited chemistry which has been developed for these elements. Indeed, the chemistry of this series of metals is sufficiently narrow that it can be summarized in a single paragraph.

Organolanthanoid activation of carbon monoxide: single and multiple insertion of CO into t-butyl lanthanoid bonds; X-ray crystallographic identification of a new bonding mode for a bridging enedione diolate ligand formed by formal coupling of four CO molecules

Carbon monoxide (1 equiv.) reacts with (C5H5)2– Lu(CMe3)(OC4H8) at room temperature to form the isolable dihaptoacyl complex (C5H5)2LU(η2-COCMe3), which reacts with additional CO to form the crystallographically characterized bimetallic complex (C5H5)2LuO4C12H18Lu-(C5H5)2 in which the two metals are bridged by the enedionediolate ligand 4,5-dihydroxy-2,2,7,7-tetramethyl-oct-4-ene-3,6-dionato (2–), which forms 6-membered metallocyclic rings with each metal atom.

Homogeneous catalytic activation of molecular hydrogen by lanthanoid metal complexes

Co-condensation of lanthanoid metal atoms with internal alkynes generates the first lanthanoid complexes which are capable of homogeneous catalytic activation of molecular hydrogen.

Heteroleptic t-butyl lanthanoid complexes: synthesis and X-ray crystal structure of monomeric bis(cyclopentadienyl)(t-butyl)lutetium tetrahydrofuranate

(C5H5)Lu(But), synthesized from [(C5H5)2Lu-Cl]2 and ButLi in pentane–tetrahydrofuran at –78°C, crystallizes from toluene as a monomeric tetrahydrofuran solvate which contains a 2·37 A Lu–C σ bond and a short (2·31 A) Lu–O distance; the analogous erbium complex is prepared similarly but, in the ytterbium case, the reaction generates (C5H5)2 Yb.