Arene complexes of rare-earth metals

Bochkarev, M. N.

doi:10.1070/rc2000v069n09abeh000601

Cited by 16 publications

(11 citation statements)

References 78 publications

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“…197 A most recent addition to the diverse derivative chemistry of (C 10 H 8 )Ln(THF) n complexes is the reaction of (C 10 H 8 )Yb(THF) 2 with cyclopentadienyl-subYbI 2 + 2Li(C 10 H 8 ) 98 THF (C 10 H 8 )Ln(THF) n + 2LiI (52) stituted alcohols and amines, which leads to novel half-sandwich complexes of divalent ytterbium. 199,200 The longest known organolanthanide complexes involving η 6 -arene coordination are bimetallic complexes of the type (η 6 -arene)Ln(AlCl 4 ) 3 .…”

Section: π-Arene Complexesmentioning

confidence: 99%

“…Among the non-cyclopentadienyl organolanthanides the π-arene complexes form a particularly important class of compounds, especially due to their very interesting derivative chemistry. Bis(arene)lanthanide(0) sandwich complexes have been reviewed elsewhere and thus will not be considered here. , …”

Section: π-Arene Complexesmentioning

confidence: 99%

“…In a series of studies Bochkarev et al have also demonstrated that these complexes exhibit high reactivities toward a large variety of reagents and may thus serve as highly useful starting materials for the preparation of various organolanthanides , …”

Section: π-Arene Complexesmentioning

confidence: 99%

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Synthesis and Structural Chemistry of Non-Cyclopentadienyl Organolanthanide Complexes

2002

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Over the years one major challenge has remained in organolanthanide chemistry: the synthesis of homoleptic alkyl and aryl complexes. The simplest organometallic compounds of the rare earths are the species LnR 2 or LnR 3 with the rare earth metals in their common oxidation states Ln 2+ and Ln 3+ which imply the coordination of only two or three ligands to the metal center. This is usually insufficient to meet the lanthanides' demands of steric saturation through high coordination numbers.Hence for a long time, only indirect evidence could be found for the existence of simple homoleptic organolanthanide compounds; the isolation and characterization of compounds belonging to this class were first achieved recently using pentafluorophenyl for Ln 2+ derivatives 12 and very bulky alkyl ligands for Ln 3+ species. [13][14][15] Especially for alkyls, very little structural data are available for compounds without any trimethylsilyl-substituted ligands which generally ensure higher stability. But nevertheless, due to the difficulties of their synthesis and their high reactivity alkyls and aryls still represent an interesting class of compounds. 16 Homoleptic σ-Alkyl ComplexesShortly after the synthesis of the first divalent solvent-free Ln alkyl, [(Me 3 Si) 3 C] 2 Yb, 17 the Eu analogue was prepared similarly by the reaction of EuI 2 and KC(SiMe 3 ) 3 in benzene. 18 It also features the bent structure displayed by the Yb complex but with a slightly smaller C-Eu-C angle (C-Eu-C ) 136°, C-Yb-C ) 137°) and longer Eu-C bonds (Eu-C ) 261 pm, Yb-C ) 249/250 pm). Salt metathesis was then again applied successfully to synthesize the first divalent Sm alkyl, Sm[C(SiMe 3 ) 2 (SiMe 2 OMe)] 2 (THF) Frank T. Edelmann was born in Hamburg, Germany, in 1954. He studied chemistry from 1974 to 1979 at the University of Hamburg, where he obtained his Diplom in 1979 and doctoral degree in 1983. His Ph.D. thesis entitled "The chemistry of the tricarbonyl(fulvene) chromium complexes" was carried out under the supervision of Prof. Ulrich Behrens. This was followed by two years (1983−1985) of postdoctoral research as a Feodor Lynen Fellow of the Alexander-von-Humboldt Foundation in the groups of Professors Josef Takats (

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Section: π-Arene Complexesmentioning

confidence: 99%

Section: π-Arene Complexesmentioning

confidence: 99%

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Synthesis and Structural Chemistry of Non-Cyclopentadienyl Organolanthanide Complexes

2002

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“…35 In [(η 6 -C 6 H 4 -(CHMe 2 )-4-Me-1)Ru(η 6 -DMI)][BPh 4 ], DMI is coordinated in an η 6 mode to cationic Ru via the arene ring. 34 Since the electrophilic lanthanides can also interact with arene rings of anionic ligands, [36][37][38] this provides an additional bonding option. We report here on the complexation chemistry of DMI with potassium, yttrium, and samarium.…”

Section: Introductionmentioning

confidence: 99%

Flexibility in the Coordination Chemistry of the 2,3-Dimethylindolide Ligand with Potassium, Yttrium, and Samarium

Evans

Brady

2002

Inorg. Chem.

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The coordination chemistry of the 2,3-dimethylindolide anion (DMI), (Me(2)C(8)H(4)N)(-), with potassium, yttrium, and samarium ions is described. In the potassium salt [K(DMI)(THF)](n), 1, prepared from Me(2)C(8)H(4)NH and KH in THF, the dimethylindole anion binds and bridges potassium ions in three different binding modes, namely eta(1), eta(3), and eta(5), to form a two-dimensional extended structure. In the dimethoxyethane (DME) adduct [K(DMI)(DME)(2)](2), 2, prepared by crystallizing a sample of 1 from DME, DMI exists as a mu-eta(1):eta(1) ligand. Compound 1 reacts with SmI(2)(THF)(4) in THF to form the distorted octahedral complex trans-(DMI)(2)Sm(THF)(4), 3, in which the dimethyindolide anions are bound in the eta(1) mode to samarium. Reaction of 2,3-dimethylindole with Y(CH(2)SiMe(3))(3)(THF)(2) afforded the amide complex (DMI)(3)Y(THF)(2), 4, in which the dimethylindolide anions are also bound in the eta(1) mode to yttrium. Compound 1 also reacts with (C(5)Me(5))(2)LnCl(2)K(THF)(2) (Ln = Sm, Y) to form unsolvated amide complexes (C(5)Me(5))(2)Ln(DMI) (Ln = Sm, 5; Y, 6), in which DMI attaches primarily through nitrogen, although the edge of the arene ring is oriented toward the metals at long distances.

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“…While additional toluene ligands do not displace the HB(C 6 F 5 ) 3 to generate solvent-separated ion pairs, one HB(C 6 F 5 ) 3 coordinates in the bidentate mode noted above. A few classes of trivalent rare earth arene compounds have been reported, , including tetrachloroaluminates first prepared by Cotton , and later expanded to include a range of lanthanide and arene combinations, such as (η 6 -C 6 H 6 )Nd(AlCl 4 ) 3 (Nd–C ave = 2.90 Å) . Arene compounds containing alkyltrichloroaluminates, such as (η 6 -C 6 H 6 )Nd(AlMeCl 3 ) 3 (Nd–C ave = 2.96 Å), are also effective precatalysts for butadiene polymerization (upon activation with diisobutylaluminum hydride or dibutylmagnesium) that give comparable activities to the neodymium carboxylates .…”

Section: Resultsmentioning

confidence: 99%

Zwitterionic Trivalent (Alkyl)lanthanide Complexes in Ziegler-Type Butadiene Polymerization

et al. 2018

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The organolanthanide complexes Ln{C(SiHMe 2) 3 } 3 (Ln = La, 1a; Ce, 1b; Pr, 1c; Nd, 1d) react with one or two equiv. of B(C 6 F 5) 3 to yield the well-defined zwitterionic species Ln{C(SiHMe 2) 3 } 2 HB(C 6 F 5) 3 (Ln = La, 2a; Ce, 2b; Pr, 2c; Nd, 2d) or LnC(SiHMe 2) 3 {HB(C 6 F 5) 3 } 2 (Ln = La, 3a; Ce, 3b; Pr, 3c; Nd, 3d), respectively. These complexes are shown to contain labile, bridging Si-H⇀Ln and oF ->Ln interactions based upon the observation of low one-bond silicon-hydrogen coupling constants (1 J SiH) in 1 H NMR spectra of 2a and 3a, the presence of one set of C 6 F 5 signals in the 19 F NMR spectra of 2a and 3a, the detection of only m-F and p-F resonances in 19 F NMR spectra of 2b-d and 3b-d, two ν SiH bands in IR spectra of 2a-d, and X-ray crystallography analyses of 2b and 3d. In addition, a hexametertoluene molecule is coordinated to neodymium in 3d. Reactions of 1a and (AlMe 3) 2 yield labile adducts with an approximate stoichiometry of 1a•3AlMe 3. Exchange between free and bound AlMe 3 groups was observed in EXSY NMR experiments with greater than 3 equiv. of AlMe 3. Compounds 2a-d and 3a-d, in the presence of AliBu 3 , are precatalysts for polymerization of butadiene. The neodymium alkyl 3d has the highest activity of the series, and its performance is consistent with chain transfer reactions with AliBu 3 .

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Arene complexes of rare-earth metals

Cited by 16 publications

References 78 publications

Synthesis and Structural Chemistry of Non-Cyclopentadienyl Organolanthanide Complexes

Synthesis and Structural Chemistry of Non-Cyclopentadienyl Organolanthanide Complexes

Flexibility in the Coordination Chemistry of the 2,3-Dimethylindolide Ligand with Potassium, Yttrium, and Samarium

Zwitterionic Trivalent (Alkyl)lanthanide Complexes in Ziegler-Type Butadiene Polymerization

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