Double Deprotonation of a Cyclopentadienyl Alkene to Form a Polydentate Trianionic Cyclopentadienyl Allyl Ligand System

Abstract

An important part of the evolution of metallocene chemistry and metallocene-based polymerization chemistry has been the development of cyclopentadienyl ligands to which other donor functionalities have been attached. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] Ligand systems have been designed which involve monoanionic cyclopentadienides attached to neutral ether, amine, and hydrocarbon groups as well as dianionic ansa ligands in which the cyclopentadienide is attached to another anionic donor such as a cyclopentadienide or amide.

Synthesis and Structures of the C5Me4SiMe3‐Supported Polyhydride Complexes over the Full Size Range of the Rare Earth Series

“…(Cp* = C 5 Me 5 ), [8] [(Cp*)LuA C H T U N G T R E N N U N G (CH 2 SiMe 3 ){CHA C H T U N G T R E N N U N G (SiMe 3 ) 2 }A C H T U N G T R E N N U N G (thf)], [8] [(Cp*)Gd-A C H T U N G T R E N N U N G (CH 2 Ph) 2 A C H T U N G T R E N N U N G (thf)], [9] [(C 5 Me 4 SiMe 2 X)YA C H T U N G T R E N N U N G (CH 2 SiMe 3 ) 2 A C H T U N G T R E N N U N G (thf)] (X = Me, Ph, C 6 F 5 ), [10] [(C 5 Me 4 SiMe 2 CH 2 CHCH 2 )YA C H T U N G T R E N N U N G (CH 2 SiMe 3 ) 2 -A C H T U N G T R E N N U N G (thf) 2 ], [11] [(Cp')LnA C H T U N G T R E N N U N G (CH 2 SiMe 3 ) 2 A C H T U N G T R E N N U N G (thf)] (Ln = Sc, Gd, Dy, Lu), [3k] [{1,3-(Me 3 Si) 2 …”

Recent Advances in the Design and Coordination Chemistry of Heteroscorpionate Ligands Bearing Stereogenic Centres

“…As mentioned above, deprotonation of the cyclopentadiene moiety is a well-known procedure that normally proceeds by either acid-base or protonolysis processes. [24] Thus, the reaction of bpztcpH with [M(CH 2 SiMe 3 ) 3 (THF) 3 ] [28] (M = Sc, Y) yielded the THF-free scandium and yttrium alkyl complexes [M(CH 2 SiMe 3 ) 2 (bpztcp)] bearing a hybrid scorpionate/cyclopentadienyl ligand with a stereogenic centre (Scheme 25). This process gave complexes in yields of up to 70 %.…”

Mono(cyclopentadienyl) Complexes of the Rare-Earth Metals

“…NMR spectroscopic studies did not indicate an interaction of the allyl function with the metal center. 133 The yellow dibenzyl gadolinium complex [Gd(η 5 -C 5 Me 5 )(CH 2 Ph) 2 (THF)] was obtained by salt metathesis of GdBr 3 with K(C 5 Me 5 ) and benzyl potassium in THF and characterized by X-ray crystallography as type I. The ipso-carbon atoms of the benzyl ligands interact with the gadolinium center, with rather small angles at the R-carbon atoms (92.1(4)°and 96.4(4)°).…”