Lanthanide indenyl complexes

Lanthanide indenyl complexes of Ln(III) are known. Ce(IV), Sm(II) also form indenyl complexes. Mixed cyclopentadienyl-indenyl complexes of lanthanides have been prepared by reacting CpLnCl with NaC9H7. Typical preparation involves the reaction [221]... 

In recent years, a series of divalent lanthanide heteroatom-functionalized indenyl complexes have been synthesized by the reaction of [(Me3Si)2N]3Ln(p.-Cl)Li(THF)3 or [(Me3Si)2N]3Ln (Ln = Yb, Eu) with heteroatom-functionalized indene via so-called heteroatom coordination promoted homolysis of the Ln-N bond as shown in Figure 8.30 [99,100]. 

The synthesis and characterization of the first bis- and tris[ 1 -(tu-alken-l-yl)indenyl] lanthanide complexes (Ln = Gd, Er, Y, Lu) have been reported. l-Allyl-2,4,7-trimethyl-lFI-indene and l-(3-buten-l-yl)-4,7-dimethyl-lH-indene were prepared from (2,4,7-trimethylindenyl)lithium and allyl chloride or from (4,7-dimethylindenyl)lithium and 4-bromo-l -butene.677 The reactions of the trichlorides of gadolinium, erbium, yttrium, lutetium, and ytterbium in molar ratios in TFIF produce the bis(l-allyl-2,4,7-trimethylindenyl)lanthanide chloride complexes L2LnCl(THF) (Ln = Gd, Er), bis( 1 -buten-1-yM,7-dimcthyIindcnyI)lanthanide complexes (Ln = Y, Lu) or the heterometallic complexes bis(l-buten-l-yl-4,7-dimethylindenyl)Yb(/r-Cl)2Li(THF)2 (Scheme 180).677... 

Bis(indenyl)lanthanide thiolate complexes of the type (C9pl7)2LnSR(THF) are formed in the reaction of tris(in-denyl) lanthanide with equimolar amounts of thiols (Scheme 182). The complexes were characterized by elemental... 

The base-free tris(indenyl) lanthanide(m) complexes (C9H7)3Ln (Ln = Nd, Pr, La) were prepared from the corresponding tetrahydrofuran adducts (C9H7)3Ln(THF). The strictly THF-free complexes are obtained when the... 

Fig. 11 Fluorenyl- and indenyl-functionalized carbene lanthanide dialkyl complexes...

Lanthanide and Actinide Elements.- The chemistry of organo-lanthan-Ide compounds, including Cp and indenyl complexes, has been re-... 

After rinzinger s initiator discussed above, a variety of metallocene- and non-met-allocene-based classes of ethylene polymerization initiators also including lanthanide metallocene complexes have been developed In the metallocene series, particularly noteworthy are ordan s MAO-free 1 -electron catalyst p r 1 h and Waymouth s bis 3 phenyl indenyl zirconium dichloride, the latter providing isotactic-atactic block polypropylene... 

Both lanthanides and actinides give complexes with the indenyl ligand (C9H7) (Ind) which is formally analogous to C5H5", but makes a considerably greater steric demand. With the exception of cerium which forms both Ce" and Ce derivatives, and Sm, which forms both Sm" and Sm " derivatives, all lanthanides form Ln" indenyl complexes. 

There has also been some interest in NHC-lanthanide complexes as polymerisation catalysts. Indenyl and fluorenyl functionalised NHC complexes of structures 14 and 15 (Fig. 4.5) were evaluated for isoprene polymerisation following activation... 

Many other lanthanide-based initiators have been shown to polymerize MMA, including lanthanocene amides,464 168 alkoxides,469 substituted indenyl and fluorenyl bivalent ytterbocenes,470,471 hexamethylphosphoric triamide thiolates,472 and allyl, azaallyl, and diazapentadienyl complexes.473... 

Patents have been reported for a series of bimetallic metallocene catalysts based on lanthanide and group IV metals. The bridging ligand is a substituted ethyl-linked fluorenyl indenyl bearing a substituent of varying length [26]. The complexes are reported to act as good olefin polymerization catalysts in the presence of MAO.52,53... 

Tris(indenyl)lanthanide complexes of all rare earth metals can be prepared analogously from the lanthanide trichlorides with alkali or magnesium indenyl salts. All five-membered rings are -bonded to the metal. They form base adducts with... 

Bis(indenyl)lanthanide complexes are also described. According to X-ray crystallographic investigations (C4H7-OCH2C9H6)2LnCl (Ln = Nd, Sm, Dy, Ho, Er, Yb) (Figure 39) are unsolvated nine-coordinate monomeric complexes with a... 

Tris(indenyl)lanthanide complexes are isolated as the monotetrahydrofuranates and freed of solvent by heating to 70°C in vacuo. The recent synthesis of tris(heptamethy-lindenyOlanthanide complexes is of note since attempts to prepare the closely related M(Cp -> )3 complexes have been unsuccessful . 

Following the synthesis of tris(cyclopentadienyl) lanthanide complexes, the first examples of organolanthanide derivatives, a vast number of organolanthanide it-complexes with cyclopen-tadienyl (Cp), indenyl (Ind), cyclooctatetraenyl (COT), and related substituted derivatives have been prepared and extensively reviewed [3]. Here we will briefly discuss cyclopentadienyl and allyl derivatives as representatives of organolanthanide K-complexes. 

For the lanthanide metals, Sm, Eu, and Yb, which have a readily accessible ( + 2) oxidation state, oxidative addition reactions of M(1I) complexes with halogens and organic halides are dominated by the atom transfer or free radical mechanism (cf. 5.S.2.9.1.) in which two metal ions are each oxidized to the -I- 3 state. Numerous examples illustrate the ability of cyclopentadienyl or indenyl Ln(II) complexes (Ln = Sm, Eu, Yb) to abstract halogen atoms from molecular halogens ", halogenated solvents sueh as CH2CI2 and and alkyl halides . An archetypieal example is ... 

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