0000000000749647
AUTHOR
Alexander T. Trifonov
Di‐ and Trivalent Ytterbium Complexes Containing Linked Amino‐ and Amidocyclopentadienyl Ligands
Reactions of the aminocyclopentadienes (C5Me4H)SiMe2NHR (R = Et, allyl, nPr, tBu) with [YbI2(THF)2] in the presence of two equivalents of potassium 1,2-diphenylethenide in THF at room temperature gave the diamagnetic half-sandwich complexes [Yb(η5-C5Me4SiMe2NHR)Ln(μ-I)]2 (L = THF, n = 2, L = DME, n = 1). The tert-butylamido derivative [Yb(η5-C5Me4SiMe2NHtBu)(THF)2(μ-I)]2 was characterized by X-ray structural analysis as a dinuclear complex containing a nonchelating aminocyclopentadienyl ligand. Deprotonation of the aminocyclopentadiene (C5H4tBu)SiMe2NHtBu with two equivalents of potassium 1,2-diphenylethenide in THF, followed by reaction with [YbI2(THF)2] at 60 °C, gave the trivalent ytterb…
Metalation of aromatic heterocycles by yttrium alkyl complexes that contain a linked amido-cyclopentadienyl ligand: synthesis, structure and Lewis base adduct formation
Abstract The reaction of the half-sandwich alkyl complex [Y(η5:η1-C5Me4SiMe2NCMe3)(CH2SiMe3)(THF)] with furan and thiophene gives metalation products [Y(η5:η1-C5Me4SiMe2NCMe3)(μ-2-C4H3X)]2 (X=O, S) which are sparingly soluble in hydrocarbons due to the dimeric structure. Single crystal X-ray structure analysis of the 2-thienyl complex confirms a six-membered core with bridging sulfur atoms and trans-disposed amido-tetramethylcyclopentadienyl ligands. In contrast to THF and pyridine, 1,2-dimethoxyethane (DME) forms isolable, crystalline adducts [Y(η5:η1-C5Me4SiMe2NCMe3)(2-C4H3X)(DME)]. Single crystal X-ray structure analysis of the 2-furyl derivative shows a four-legged piano stool configura…