Organometallic compounds of the lanthanides XCVII. Synthesis and crystal structures of monomeric bis(ethyltetramethylcyclopentadienyl) amide and alkyl derivatives of the lanthanides

Schumann, Herbert; Rosenthal, Esther C. E.; Kociok‐Köhn, Gabriele; Molander, Gary A.; Winterfeld, Jörn

doi:10.1016/0022-328x(95)05496-c

Cited by 37 publications

(29 citation statements)

References 33 publications

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“…The conformation of the amido ligands is remarkable. The angle N-Si-C(14) (105.82(13)°) is clearly smaller than the angles N-Si-C(15) (114.08(13)°) and N-Si-C(16) (114.82(14)°), which is in accordance with the situation in (C 5 Me 4 Et) 2 YN-(SiMe 3 ) 2 (107.4/115.1°) 29 and in (C 5 Me 5 ) 2 SmN(SiMe 3 ) 2 (106.3/114.6°). 30 These distortions are the consequence of γ-agostic interactions between the methyl groups of the bis(trimethylsilyl)amido ligand and the unsaturated samarium center, as was discussed also in the cases of (C 5 Me 4 Et) 2 YN(SiMe 3 ) 2 29 and (C 5 Me 5 ) 2 SmN(SiMe 3 ) 2 .…”

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confidence: 87%

“…The largest deviation of the ideal 120°angle is, with respect to the large butenyl substituent on the cyclopentadienyl ligands, slightly smaller for Cp-Sm-Cp (130.49(4)°) than in (C 5 Me 4 Et) 2 YN(SiMe 3 ) 2 (Cp-Y-Cp ) 132.59°) 29 and in (C 5 Me 5 ) 2 SmN(SiMe 3 ) 2 (Cp-Sm-Cp ) 132.8°). 30 There is no coordination of the olefinic double bond of the CH 2 dCHCH 2 CH 2 C 5 Me 4 ligand to the samarium center.…”

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confidence: 94%

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Organometallic Compounds of the Lanthanides. 156.¹ ω-Alkenyl-Functionalized Cyclopentadienyl Complexes of Yttrium, Samarium, Ytterbium, and Lutetium

et al. 2002

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react with the lithium, sodium, and potassium salts of 1-(but-3-enyl)-2,3,4,5-tetramethylcyclopentadiene, yielding [(CH 2 dCHCH 2 CH 2 C 5 Me 4 ) 2 LnCl] 2 (Ln ) Y (3a), Sm (3b), Lu (3c)) and (CH 2 dCHCH 2 CH 2 C 5 Me 4 ) 2 Yb (6), respectively. The monomeric THF adducts (CH 2 dCHCH 2 CH 2 C 5 Me 4 ) 2 LnCl(THF) (Ln ) Y (2a), Sm (2b)) crystallize from hexane. Li[C 5 Me 4 CH 2 CH 2 CH 2 CHdCH 2 ] reacts with SmCl 3 , yielding (CH 2 dCHCH 2 CH 2 CH 2 C 5 -Me 4 ) 2 SmCl(THF) (5b). The reaction of YCl 3 , SmCl 3 , and LuCl 3 with 1 equiv of M[C 5 Me 4 -CH 2 CH 2 CHdCH 2 ] followed by M[C 5 Me 5 ] (M ) Na, K) gives [(CH 2 dCHCH 2 CH 2 C 5 Me 4 )(C 5 - (9c)). The NaCl adduct (CH 2 dCHCH 2 CH 2 C 5 Me 4 )(C 5 Me 5 )-Y(µ-Cl) 2 Na(Et 2 O) 2 (8a) crystallizes from Et 2 O. The cyclopentadienyllanthanide halides 3a,b and 9b react with LiMe, LiCH(SiMe 3 ) 2 , and LiN(SiMe 3 ) 2 , forming the corresponding unstable alkyl derivatives (CH 2 dCHCH 2 CH 2 C 5 Me 4 ) 2 LnR (Ln ) Y, R ) Me (10a), CH(SiMe 3 ) 2 (11a); Ln ) Sm, R ) CH(SiMe 3 ) 2 (11b)), and (CH 2 dCHCH 2 CH 2 C 5 Me 4 )(C 5 Me 5 )YCH(SiMe 3 ) 2 (12a), as well as (CH 2 dCHCH 2 CH 2 C 5 Me 4 ) 2 SmN(SiMe 3 ) 2 (13b). 10a, 11a,b, and 12a have been characterized by mass spectrometry, whereas all data of 13b have been obtained. The trichlorides of Y, Sm, and Lu react with 2 equiv of the sodium and potassium salts of 1-(4-methylpent-3-enyl)-2,3,4,5-tetramethylcyclopentadiene, yielding [(Me 2 CdCHCH 2 CH 2 C 5 Me 4 ) 2 -LnCl] 2 (Ln ) Y (15a), Sm (15b), Lu (15c)) or with 1 equiv of M[C 5 Me 4 CH 2 CH 2 CHdCMe 2 ] followed by M[C 5 Me 5 ] (M ) Na, K), yielding [(Me 2 CdCHCH 2 CH 2 C 5 Me 4 )(C 5 Me 5 )LnCl] 2 (Ln ) Y (17a), Sm (17b), Lu (17c)). The monomeric NaCl adduct (Me 2 CdCHCH 2 CH 2 C 5 Me 4 )(C 5 -Me 5 )Lu(µ-Cl) 2 Na(OEt 2 ) 2 (16c) crystallizes from Et 2 O. The structures of 2a,b, 8a, 13b, and 16c were determined by single-crystal X-ray diffraction.

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confidence: 87%

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confidence: 94%

Organometallic Compounds of the Lanthanides. 156.¹ ω-Alkenyl-Functionalized Cyclopentadienyl Complexes of Yttrium, Samarium, Ytterbium, and Lutetium

et al. 2002

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“…125 Hz in sp 3 C–H bonds. ,,, The low coordinate tris-bis(trimethylsilyl)methyl lanthanide complexes, Ln[CH(SiMe 3 ) 3 ] 3 , with Ln = Y, La, Ce, and Sm, contain unusually short distances between the metal and one −SiMe 3 group of the pendant alkyl in their X-ray crystal structures. The distortion of a CH(SiMe 3 ) 2 group is also a general pattern observed in the crystal structures of Cp* 3– x Ln[CH(SiMe 3 ) 2 ] x , where x = 1 or 2. − Regardless of the reasons, these secondary interactions are a signature of the electrophilicity of the lanthanide in these compounds.…”

Section: Introductionmentioning

confidence: 82%

The Nature of Secondary Interactions at Electrophilic Metal Sites of Molecular and Silica-Supported Organolutetium Complexes from Solid-State NMR Spectroscopy

et al. 2016

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Lu[CH(SiMe3)2]3 reacts with [SiO2-700] to give [(≡SiO)Lu[CH(SiMe3)2]2] and CH2(SiMe3)2. [(≡SiO)Lu[CH(SiMe3)2]2] is characterized by solid-state NMR and EXAFS spectroscopy, which show that secondary Lu···C and Lu···O interactions, involving a γ-CH3 and a siloxane bridge, are present. From X-ray crystallographic analysis, the molecular analogues Lu[CH(SiMe3)2]3-x[O-2,6-tBu-C6H3]x (x = 0-2) also have secondary Lu···C interactions. The (1)H NMR spectrum of Lu[CH(SiMe3)2]3 shows that the -SiMe3 groups are equivalent to -125 °C and inequivalent below that temperature, ΔG(⧧)(Tc = 148 K) = 7.1 kcal mol(-1). Both -SiMe3 groups in Lu[CH(SiMe3)2]3 have (1)JCH = 117 ± 1 Hz at -140 °C. The solid-state (13)C CPMAS NMR spectrum at 20 °C shows three chemically inequivalent resonances in the area ratio of 4:1:1 (12:3:3); the J-resolved spectra for each resonance give (1)JCH = 117 ± 2 Hz. The (29)Si CPMAS NMR spectrum shows two chemically inequivalent resonances with different values of chemical shift anisotropy. Similar observations are obtained for Lu[CH(SiMe3)2]3-x[O-2,6-tBu-C6H3]x (x = 1 and 2). The spectroscopic data point to short Lu···Cγ contacts corresponding to 3c-2e Lu···Cγ-Siβ interactions, which are supported by DFT calculations. Calculated natural bond orbital (NBO) charges show that Cγ carries a negative charge, while Lu, Hγ, and Siβ carry positive charges; as the number of O-based ligands increases so does the positive charge at Lu, which in turns shortens the Lu···Cγ distance. The change in NBO charges and the resulting changes in the spectroscopic and crystallographic properties show how ligands and surface-support sites rearrange to accommodate these changes, consistent with Pauling's electroneutrality concept.

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“…The Y-N(1) and Y-N(2) bond lengths are 0.084 and 0.079 Å respectively, shorter than the Y-N(3) bonds, but essentially the same as those in 7, due to this competition for lone-pair donation between silicon and yttrium that occurs at N(3) but not at the more basic, non-silylamide centres N(1) and N(2). The Y-N(SiMe 3 ) 2 bond length of 2.272(3) Å is essentially the same as those in the homoleptic complex [Y{N(SiMe 3 ) 2 } 3 ] 33 (2.224(6) Å) and in the heteroleptic complexes [YCp* 2 {N(SiMe 3 ) 2 }] 20 (two independent molecules in the unit cell; Y(1)-N(1) 2.274(5) Å, Y(2)-N(2) 2.253(5) Å) and [Y(C 5 Me 4 Et) 2 -{NSiMe 3 ) 2 }] 34 (2.276(3) Å). As for 6, the relatively low yttrium coordination number and the proximal silylmethyl groups lead to the possibility of agostic interactions between these functionalities in the solid state.…”

Section: Synthesis Of Yttrium Complexes Supported By {Arn(ch 2 ) 3 Na...mentioning

confidence: 99%

Yttrium complexes incorporating the chelating diamides {ArN(CH₂)_xNAr}²⁻(Ar = C₆H₃-2,6-ⁱPr₂, x = 2, 3) and their unusual reaction with phenylsilane

et al. 2004

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Novel yttrium chelating diamide complexes [(Y[ArN(CH(2))(x)NAr](Z)(THF)(n))(y)] (Z = I, CH(SiMe(3))(2), CH(2)Ph, H, N(SiMe(3))(2), OC(6)H(3)-2,6-(t)Bu(2)-4-Me; x = 2, 3; n = 1 or 2; y = 1 or 2) were made via salt metathesis of the potassium diamides (x = 3 (3), x = 2 (4)) and yttrium triiodide in THF (5,10), followed by salt metathesis with the appropriate potassium salt (6-9, 11-13, 15) and further reaction with molecular hydrogen (14). 6 and 11(Z = CH(SiMe(3))(2), x = 2, 3) underwent unprecedented exchange of yttrium for silicon on reaction with phenylsilane to yield (Si[ArN(CH(2))(x)NAr]PhH) (x = 2 (16), 3) and (Si[CH(SiMe(3))(2)]PhH(2)).

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Organometallic compounds of the lanthanides XCVII. Synthesis and crystal structures of monomeric bis(ethyltetramethylcyclopentadienyl) amide and alkyl derivatives of the lanthanides

Cited by 37 publications

References 33 publications

Organometallic Compounds of the Lanthanides. 156.¹ ω-Alkenyl-Functionalized Cyclopentadienyl Complexes of Yttrium, Samarium, Ytterbium, and Lutetium

Organometallic Compounds of the Lanthanides. 156.¹ ω-Alkenyl-Functionalized Cyclopentadienyl Complexes of Yttrium, Samarium, Ytterbium, and Lutetium

The Nature of Secondary Interactions at Electrophilic Metal Sites of Molecular and Silica-Supported Organolutetium Complexes from Solid-State NMR Spectroscopy

Yttrium complexes incorporating the chelating diamides {ArN(CH₂)_xNAr}²⁻(Ar = C₆H₃-2,6-ⁱPr₂, x = 2, 3) and their unusual reaction with phenylsilane

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Organometallic compounds of the lanthanides XCVII. Synthesis and crystal structures of monomeric bis(ethyltetramethylcyclopentadienyl) amide and alkyl derivatives of the lanthanides

Cited by 37 publications

References 33 publications

Organometallic Compounds of the Lanthanides. 156.1 ω-Alkenyl-Functionalized Cyclopentadienyl Complexes of Yttrium, Samarium, Ytterbium, and Lutetium

Organometallic Compounds of the Lanthanides. 156.1 ω-Alkenyl-Functionalized Cyclopentadienyl Complexes of Yttrium, Samarium, Ytterbium, and Lutetium

The Nature of Secondary Interactions at Electrophilic Metal Sites of Molecular and Silica-Supported Organolutetium Complexes from Solid-State NMR Spectroscopy

Yttrium complexes incorporating the chelating diamides {ArN(CH2)xNAr}2−(Ar = C6H3-2,6-iPr2, x = 2, 3) and their unusual reaction with phenylsilane

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Organometallic Compounds of the Lanthanides. 156.¹ ω-Alkenyl-Functionalized Cyclopentadienyl Complexes of Yttrium, Samarium, Ytterbium, and Lutetium

Organometallic Compounds of the Lanthanides. 156.¹ ω-Alkenyl-Functionalized Cyclopentadienyl Complexes of Yttrium, Samarium, Ytterbium, and Lutetium

Yttrium complexes incorporating the chelating diamides {ArN(CH₂)_xNAr}²⁻(Ar = C₆H₃-2,6-ⁱPr₂, x = 2, 3) and their unusual reaction with phenylsilane