Substituted Ring‐Fused Yttrium Derivatives – X‐ray Crystal Structures of [(L′YCl₂·THF)₂LiCl·2THF] and [{L′YCl(OH)}₆·2THF] (L′ = 2‐Phenyl‐4,5,6,7,8‐hexahydroazulenyl)

Abstract

The reaction of lithium salts of ring‐fused ligands (L), where the ring fused to the cyclopentadienyl moiety is a saturated one (six, seven, or eight carbon atoms), with YCl3 in THF in 2:1 and 1:1 molar ratios affords complexes of formula [L2YCl]2 and [(LYCl2·THF)2LiCl·2THF], respectively. Here we report the synthesis, spectroscopic characterization, and X‐ray crystal structure of [(L′YCl2·THF)2LiCl·2THF] (L′ = 2‐phenyl‐4,5,6,7,8‐hexahydroazulenyl), together with the crystal structure of the hexameric species [{L′YCl(OH)}6·2THF], which was quite unexpectedly isolated during the attempted crystallization of the latter complex and is probably formed by partial hydrolysis of that complex. The activity of the new complexes towards ethylene and 1‐hexene polymerization reactions was also tested. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Rare-Earth-Metal Allyl Complexes Supported by the [2-(N,N-Dimethylamino)ethyl]tetramethylcyclopentadienyl Ligand: Structural Characterization, Reactivity, and Isoprene Polymerization

“…Examples include [Nd 6 (2,4-C 7 H 11 ) 6 Cl 12 (thf) 2 ], [Ln 6 (C 5 Me 5 ) 6 Cl 12 (thf) 2 ] (Ln = Nd, Sm), [Ln 6 (C 5 Me 4 n Pr) 6 (BH 4 ) 12– x Cl x (thf) 2 ] (Ln = Sm, Nd; x = 0, 5, 10), and [Sm 6 (C 5 Me 5 ) 6 Cl 10 (OH) 2 (thf) 2 ] . The yttrium complex [Y 6 (L) 6 Cl 6 (OH) 6 (thf) 2 ] (L = 2-phenyl-1,4,5,6,7,8-hexahydroazulenyl) represents a rare example of a [Ln 6 X 12 ] cluster with a smaller rare-earth-metal center . Herein the hydroxo ligands occupy the two μ 3 and one μ 2 position in the trimeric subunit.…”

“…55 The yttrium complex [Y 6 (L) 6 Cl 6 (OH) 6 (thf) 2 ] (L = 2-phenyl-1,4,5,6,7,8-hexahydroazulenyl) represents a rare example of a [Ln 6 X 12 ] cluster with a smaller rare-earth-metal center. 56 Herein the hydroxo ligands occupy the two μ 3 and one μ 2 position in the trimeric subunit. In addition to the η 5 -coordinated cyclopentadienyl ligand, two of the metal centers in each triangle accommodate five anionic ligands X, while the third has only contact to four X.…”

Yttrium half-sandwich complexes bearing the 2-(N,N-dimethylamino)ethyl-tetramethylcyclopentadienyl ligand

“…LiCl(thf) 2 ][17] and displays the same trinuclear core as the yttrium chloro complex [(L)YCl 2 (thf) 2 ] 2 [LiCl(thf) 2 ] (L ¼ 2-phenyl-1,4,5,6,7,8-hexhydroazulenyl)[18], which contains two thf molecules coordinating towards the yttrium metal centre instead of the intramolecular nitrogen function. Two yttrium and one lithiummetal centres are bridged by three m 2 -Cl and two m 3 -Cl anions (Fig.…”