Benzylverbindungen elektronenarmer Übergangsmetalle. Molekülstrukturen von Cp2Ti(CH2Ph)2 und CpZr(CH2Ph)3

Scholz, Joachim; Rehbaum, F.; Thiele, K.‐H.; Goddard, Richard; Betz, P.; Krüger, Carl

doi:10.1016/0022-328x(93)80014-3

Cited by 49 publications

(26 citation statements)

References 45 publications

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“…This situation is ascribed to r/2-coordination of the benzylic fragment. Comparable angle values have been found in the sterically crowded aryl oxide [Zr(OC6H~Bu2)(CH2Ph)3] (84 °) [28]] and in the electronically deficient cationic derivatives [Zr(CH2Ph)3{B(CH2Ph)(C6Fs)3}] + (82.7 °) [35] and [Zr(CsHs)2(CH2Ph)(CH3CN)] + (84.9 °) [36], although the angle is smaller than those reported in the cyclopentadienyl ring free complex [Zr(CH2Ph)4(dmpe)] (94.2(4) °) [37] and the related monocyclopentadienyl compound [Zr(CsHs)(CH2Ph)3] (94.5(5) °) [38]. The second benzyl ligand bonded to the metal through C41 has a Zr-C-Ph angle of 122.4(11) °, consistent with a normal r/l-bonding mode.…”

Section: Description Of the Crystal Structure Of [Zr(~l 5-c 5 H4(simementioning

confidence: 52%

“…The third benzyl ligand has a Zr-C-Ph angle of 102.0(13) ° suggesting an intermediate interaction between the aromatic fragment and the metal centre. Several transition metal complexes showing different modes of ligation of the benzyl ligands have been structurally characterized [28,[38][39][40]. The three C o~ atoms are bonded to Zr at the same distance, 2.27 A (average value) and define a plane almost parallel to the Cp ring plane.…”

Section: Description Of the Crystal Structure Of [Zr(~l 5-c 5 H4(simementioning

confidence: 99%

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Synthesis and reactivity of new silyl substituted monocyclopentadienyl zirconium complexes. X-ray molecular structure of [Zrη5-C5H4 (SiMe2CH2Ph)(CH2Ph)3]

Ciruelo¹,

Cuenca²,

Gómez³

et al. 1997

Journal of Organometallic Chemistry

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New silyl substituted monocyclopentadienyl complexes of Zr(IV) were synthesized from the precursor [Zr{@-CsH4(SiMe2C1)}CI 3] (1). The reaction of 1 with the lithium benzamidinate salt Li[C(Ph){N(SiMe3)} 2] leads to the complex [Zr{r/5-CsHa(SiM%C1)}{C(Ph)[N(SiMe3)]2}C12 ] (2), which decomposes slowly in solution with elimination of SiMe3C1. Complex 1 reacts with alkyl, amido and alkoxo transfer reagents (4 equiv.) to afford complexes [Zr{@-CsH4(SiMe2X)}X 3] (X = NMe 2 (3), OSiMe 3 (4), CH2CMe2Ph (5), C6H 5 (6), C6F 5 (7) and CH2SiMe 3 (8)) in good yields. Compounds 6 and 7 retain diethyl ether used as solvent but decompose as soon as they are desolvated under high vacuum conditions. Reaction of 1 with Mg(CH2Ph) 2 • 2THF (4 equiv.) yields the tetrabenzyl complex [Zr{@-CsHa(SiMe2CH2Ph)}(CH2Ph) 3] (9). The lH and 13C NMR data of the latter compound are discussed in terms of the non-classical coordination mode of the CH 2 Ph ligand, The molecular structure of [Zr{~75-C 5H4(SiMe2CH 2 Ph)}(CH2 Ph)3] 9 has been determined by X-ray diffraction methods. The coordination geometry around the zirconium atom shows a substituted @-cyclopentadienyl ring and three different benzyl ligands: a distorted ~2-benzyl group; a normal r/l-benzyl group; and a benzyl ligand with an intermediate coordination mode. The benzyl fragment bonded to silicon points away from the metal center. 9 crystallized in monoclinic space group P21/c with a = 11.268(3) A, b = 10.846(3) A, c = 27.734(6) A, /3 = 100.29(1) °, V = 3334.9(15) ~3 for Z = 4. The tetraalkylated compounds 6, 7 and 9 are excellent precursors for the preparation of the chloro derivatives. Reactions of these complexes with 3 equiv, of HC1 gave the corresponding trichloro [Zr{@-CsH4(SiMezR)}C13] (R = C6H 5 (10), C6F' 5 (11), CHePh (12)). The monochloro [Zr{@-CsH4(SiM%CH2Ph)}(CH2Ph)2C1] (13) and the dichloro derivative [Zr{@-CsH4(SiMezCHzPh)}(CHzPh)C12] (14) are observed, at 60°C and 90°C, respectively, by NMR experiments in deuterated chloroform. Complexes 10 and 11 also retain coordinated solvent, decomposing slowly when it is removed. 1 and 12 in the presence of MAO as cocatalyst, at 25°C and 1 atm of monomer pressure, cause the polymerization of ethylene with moderate activities, while under similar conditions, polymerization of propylene and styrene proceeds giving only traces of atactic materials. © 1997 Elsevier Science S.A.

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Section: Description Of the Crystal Structure Of [Zr(~l 5-c 5 H4(simementioning

confidence: 52%

Section: Description Of the Crystal Structure Of [Zr(~l 5-c 5 H4(simementioning

confidence: 99%

Synthesis and reactivity of new silyl substituted monocyclopentadienyl zirconium complexes. X-ray molecular structure of [Zrη5-C5H4 (SiMe2CH2Ph)(CH2Ph)3]

Ciruelo¹,

Cuenca²,

Gómez³

et al. 1997

Journal of Organometallic Chemistry

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“…Metallocene dichlorides (Fluka), B(C 6 F 5 ) 3 (Strem), and [PhNMe 2 H] + [B(C 6 F 5 ) 4 ] − (Strem) were used as received. [Cp 2 ZrMe 2 ],17 [${{\rm Cp}{{\ast \hfill \atop 2\hfill}}}$ ZrMe 2 ],18 [Cp 2 Ti(CH 2 Ph) 2 ],19 and [Cp 2 ZrMe] + [MeB(C 6 F 5 ) 3 ] − ( 1 a ),9 were synthesized as described in the literature. The substrates were dried by distillation from CaH 2 and stored over molecular sieves.…”

Section: Methodsmentioning

confidence: 99%

Hydroamination/Cyclization of Aminoalkenes Using Cationic Zirconocene and Titanocene Catalysts

2004

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We have become aware of a report by Bergman and co-workers that the abstraction of a methyl group from [Cp 2 ZrMe 2 ] with B(C 6 F 5) 3 leads to an acceleration of the intra-molecular hydroamination reaction of an aminoallene substrate relative to the reaction in which only [Cp 2 ZrMe 2 ] is used (L. Ackermann, R. G. Bergman, R. N. Loy, J. Am. Chem. Soc. 2003, 125, 11 956). We therefore correct our statement on p. 5543 that "alkyl metallocene cations have been used in organic synthesis, but to the best of our knowledge not in hydroamination reactions", with reference to the above-mentioned publication.

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“…Compounds TiCpCl 3 [50,51], TiCp 0 Cl 3 [52], TiCp*Cl 3 [53], TiCp*Me 3 [54], ZrCpCl 3 $DME [55] and ZrCpBz 3 [56] were prepared by a known procedure. All reactants Scheme 5.…”

Section: General Considerationsmentioning

confidence: 99%

Titanium and zirconium compounds stabilized by coordination of heteroscorpionate [N,N,O]-donor ligands. Synthesis, characterization and polymerization activity

Alesso

Tabernero

Cuenca

2012

Journal of Organometallic Chemistry

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Benzylverbindungen elektronenarmer Übergangsmetalle. Molekülstrukturen von Cp2Ti(CH2Ph)2 und CpZr(CH2Ph)3

Cited by 49 publications

References 45 publications

Synthesis and reactivity of new silyl substituted monocyclopentadienyl zirconium complexes. X-ray molecular structure of [Zrη5-C5H4 (SiMe2CH2Ph)(CH2Ph)3]

Synthesis and reactivity of new silyl substituted monocyclopentadienyl zirconium complexes. X-ray molecular structure of [Zrη5-C5H4 (SiMe2CH2Ph)(CH2Ph)3]

Hydroamination/Cyclization of Aminoalkenes Using Cationic Zirconocene and Titanocene Catalysts

Titanium and zirconium compounds stabilized by coordination of heteroscorpionate [N,N,O]-donor ligands. Synthesis, characterization and polymerization activity

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