Organo-scandium and -yttrium complexes supported by a salicylaldiminato ligand

Synthesis and Reactivity of Rare Earth Metal Alkyl Complexes Stabilized by Anilido Phosphinimine and Amino Phosphine Ligands

“…Figure 3 Synthesis of rare earth bis-alkyl complexes 4 a-d: The emergence of cationic alkyl complexes of Group 3 metals as key intermediates in homogeneous olefin polymerization [1d, 2h] has promoted interest in synthesis of rare earth metal bisalkyl precursors. Such precursors bearing non-cyclopentadienyl ligands appeared in the literature only recently, [8,9,15] and those supported by "soft" electronic donors such as phosphorus-containing ligands have not been reported, although the related diphosphanylamido ligands have been used by Roesky et al to synthesize rare earth amido and chlorido complexes. [16] We found that amido phosphine ligands HL 2-R , derivatives of the reduction product of imino phosphines, are electronically and sterically appropriate to stabilize rare earth bis-alkyl species.…”

“…[4] Recently, heteroatom compounds such as bidentate amidinates, [5] guanidinates, [6] b-diketiminates, [7] and salicylaldiminates, [8] have been extensively explored as spectator ligands by virtue of their strong metal-ligand bonds and exceptional and tunable steric and electronic features required for compensating coordinative unsaturation of metal centers and for catalytic activity towards polymerization. However, rare earth metal monoalkyl and especially bis-alkyl complexes supported by such heteroatom compounds usually undergo salt addition, dimerization, or ligand redistribution [3c] due to the highly active character of the metal-carbon bonds and relatively less crowded steric environment of the molecules.…”

Yttrium‐Amidopyridinate Complexes: Synthesis and Characterization of Yttrium‐Alkyl and Yttrium‐Hydrido Derivatives

“…[1i, 6,26] Notably, the Y-C(aryl) and Y-C(Bn) (Bn = benzyl) bonds do not react with PhSiH 3 even in the presence of a twofold excess amount of the reagent for prolonged reaction times. Indeed, all of the binuclear hydrido complexes can been recovered after stirring of the reagents for 24 h at room temperature in the presence of an excess amount of PhSiH 3 , with no appreciable decomposition.…”

“…All structures consist of a central pyridine unit substituted at its 6-position by an aryl (Figure 2, ligands 6 and 7) or a heteroaryl (Figure 2, ligands 8-10) group and at its 2-position by the same amine-containing C(Me) 2 NH(2,6-iPr 2 C 6 H 3 ) fragment. The aryl or heteroaryl moieties are almost coplanar with respect (6), N 2 H Xyl (7), N 2 H Th (8), N 2 H EtTh (9) and N 2 H BFu (10). Thermal ellipsoids are drawn at the 30 % probability level.…”

“…[2] Only recently, systems such as bidentate amidinate, [3] guanidinate, [4] β-diketiminate [5] and salicylaldiminates [6] have emerged as valuable ancillary ligands for lanthanide ions by virtue of their ability to form strong metal-ligand bonds and to allow for an easy tuning of the steric and electronic properties of the ligand. Nevertheless, lanthanide-alkyl or -hydrido complexes stabilized by these type of ligands are still fairly rare species, largely because of their troublesome preparation.…”