Metallocene derivatives of early transition elements. Part 3. Synthesis, characterisation, conformation, and rotational barriers [for the Zr-C(sp3) bond] of the zirconium(IV) complexes [Zr(η-C5H4R)2{CH-(SiMe3) 2}Cl] and the crystal and ...

Michael F. Lappert; Paul I. Riley; Paul I.W. Yarrow; Jerry L. Atwood; William E. Hunter; Michael J. Zaworotko

doi:10.1039/DT9810000814

Metallocene derivatives of early transition elements. Part 3. Synthesis, characterisation, conformation, and rotational barriers [for the Zr-C(sp³) bond] of the zirconium(IV) complexes [Zr(η-C₅H₄R)₂{CH-(SiMe₃) ₂}Cl] and the crystal and ...

Michael F. Lappert
, Paul I. Riley
, Paul I.W. Yarrow
, Jerry L. Atwood
, William E. Hunter
, Michael J. Zaworotko

Research output: Contribution to journal › Article › peer-review

Abstract

full title: Metallocene derivatives of early transition elements. Part 3. Synthesis, characterisation, conformation, and rotational barriers [for the Zr-C(sp³) bond] of the zirconium(IV) complexes [Zr(η-C₅H₄R)₂{CH-(SiMe₃) ₂}Cl] and the crystal and molecular structures of the t-butyl and trimethylsilyl complexes (R = CMe₃ or SiMe₃) The complexes [Zr(η-C₅H₄R)₂{CH(SiMe₃) ₂}Cl] have been prepared from the appropriate metallocene dichloride (R = Me, Et, Prⁱ, Bu^t, or SiMe₃) and an equimolar portion of Li[CH(SiMe₃)₂] in diethyl ether. [The same method failed to yield the hafnium analogues (for R = H or SiMe₃).] Except for R = Et, these are white or pale yellow sharp-melting crystalline solids which have been characterised by elemental analysis and i.r., ¹H, and ¹³C n.m.r. spectra. Variable-temperature ¹H n.m.r. spectra show that (i) at low temperature (coalescence temperature, T_c, -4 to 18 °C) the preferred conformation has diastereotopic pairs of SiMe₃ [of CH(SiMe₃)₂] and η-C₅H₄R groups, and (ii) ΔG^‡ for rotation about the Zr-C(sp³) bond is in the range 59.8 to 65.6 kJ mol^-1 (R = SiMe₃ > Et > Bu^t > Prⁱ ≈ Me > H). The ring cyclopentadienyl ¹³C n.m.r. signals are each split into a doublet at -30 °C but are observed as three distinct sharp singlets at 60 °C. The compounds [Zr(η-C₅H₄R)₂{CH(SiMe₃) ₂}Cl] (R = Bu^t or SiMe₃) are isostructural, crystallising in the space group P2₁/n, with cell constants, for Z = 4, being a = 10.496(6), b = 15.250(8), c = 18.272(9) Å, β = 100.48(5)° for R = Bu^t, and a = 10.525(5), b = 15.320(7), c = 19.064(8) Å, β = 98.73(4)° for R = SiMe₃. There is considerable strain within the substitued cyclopentadienyl ligands, as exemplified by the distinct spread in the range of Zr-C(π) distances and the significant deviation from the cyclopentadienyl plane of the-XMe₃ moiety. The remainder of the molecule, however, does not seem to be influenced by any steric constraints with the Zr-Cl bonds, of 2.452(2) and 2.447(1) Å (for X = C and Si respectively), and the Zr-C(σ) bonds, of 2.324(8) and 2.327(3) Å, being within previously observed limits. The conformation in the crystal corresponds to that found by low-temperature n.m.r. spectroscopy.

Original language	English
Pages (from-to)	814-821
Number of pages	8
Journal	Journal of the Chemical Society, Dalton Transactions
Issue number	3
DOIs	https://doi.org/10.1039/DT9810000814
Publication status	Published - 1981
Externally published	Yes

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Lappert, M. F., Riley, P. I., Yarrow, P. I. W., Atwood, J. L., Hunter, W. E., & Zaworotko, M. J. (1981). Metallocene derivatives of early transition elements. Part 3. Synthesis, characterisation, conformation, and rotational barriers [for the Zr-C(sp³) bond] of the zirconium(IV) complexes [Zr(η-C₅H₄R)₂{CH-(SiMe₃) ₂}Cl] and the crystal and ... Journal of the Chemical Society, Dalton Transactions, (3), 814-821. https://doi.org/10.1039/DT9810000814

Lappert, Michael F. ; Riley, Paul I. ; Yarrow, Paul I.W. et al. / Metallocene derivatives of early transition elements. Part 3. Synthesis, characterisation, conformation, and rotational barriers [for the Zr-C(sp³) bond] of the zirconium(IV) complexes [Zr(η-C₅H₄R)₂{CH-(SiMe₃) ₂}Cl] and the crystal and ... In: Journal of the Chemical Society, Dalton Transactions. 1981 ; No. 3. pp. 814-821.

@article{87bb6f44af9d45b59c1da02e54875e9a,

title = "Metallocene derivatives of early transition elements. Part 3. Synthesis, characterisation, conformation, and rotational barriers [for the Zr-C(sp3) bond] of the zirconium(IV) complexes [Zr(η-C5H4R)2\{CH-(SiMe3) 2\}Cl] and the crystal and ...",

abstract = "full title: Metallocene derivatives of early transition elements. Part 3. Synthesis, characterisation, conformation, and rotational barriers [for the Zr-C(sp3) bond] of the zirconium(IV) complexes [Zr(η-C5H4R)2\{CH-(SiMe3) 2\}Cl] and the crystal and molecular structures of the t-butyl and trimethylsilyl complexes (R = CMe3 or SiMe3) The complexes [Zr(η-C5H4R)2\{CH(SiMe3) 2\}Cl] have been prepared from the appropriate metallocene dichloride (R = Me, Et, Pri, But, or SiMe3) and an equimolar portion of Li[CH(SiMe3)2] in diethyl ether. [The same method failed to yield the hafnium analogues (for R = H or SiMe3).] Except for R = Et, these are white or pale yellow sharp-melting crystalline solids which have been characterised by elemental analysis and i.r., 1H, and 13C n.m.r. spectra. Variable-temperature 1H n.m.r. spectra show that (i) at low temperature (coalescence temperature, Tc, -4 to 18 °C) the preferred conformation has diastereotopic pairs of SiMe3 [of CH(SiMe3)2] and η-C5H4R groups, and (ii) ΔG‡ for rotation about the Zr-C(sp3) bond is in the range 59.8 to 65.6 kJ mol-1 (R = SiMe3 > Et > But > Pri ≈ Me > H). The ring cyclopentadienyl 13C n.m.r. signals are each split into a doublet at -30 °C but are observed as three distinct sharp singlets at 60 °C. The compounds [Zr(η-C5H4R)2\{CH(SiMe3) 2\}Cl] (R = But or SiMe3) are isostructural, crystallising in the space group P21/n, with cell constants, for Z = 4, being a = 10.496(6), b = 15.250(8), c = 18.272(9) {\AA}, β = 100.48(5)° for R = But, and a = 10.525(5), b = 15.320(7), c = 19.064(8) {\AA}, β = 98.73(4)° for R = SiMe3. There is considerable strain within the substitued cyclopentadienyl ligands, as exemplified by the distinct spread in the range of Zr-C(π) distances and the significant deviation from the cyclopentadienyl plane of the-XMe3 moiety. The remainder of the molecule, however, does not seem to be influenced by any steric constraints with the Zr-Cl bonds, of 2.452(2) and 2.447(1) {\AA} (for X = C and Si respectively), and the Zr-C(σ) bonds, of 2.324(8) and 2.327(3) {\AA}, being within previously observed limits. The conformation in the crystal corresponds to that found by low-temperature n.m.r. spectroscopy.",

author = "Lappert, \{Michael F.\} and Riley, \{Paul I.\} and Yarrow, \{Paul I.W.\} and Atwood, \{Jerry L.\} and Hunter, \{William E.\} and Zaworotko, \{Michael J.\}",

year = "1981",

doi = "10.1039/DT9810000814",

language = "English",

pages = "814--821",

journal = "Journal of the Chemical Society, Dalton Transactions",

issn = "1472-7773",

number = "3",

}

Lappert, MF, Riley, PI, Yarrow, PIW, Atwood, JL, Hunter, WE & Zaworotko, MJ 1981, 'Metallocene derivatives of early transition elements. Part 3. Synthesis, characterisation, conformation, and rotational barriers [for the Zr-C(sp³) bond] of the zirconium(IV) complexes [Zr(η-C₅H₄R)₂{CH-(SiMe₃) ₂}Cl] and the crystal and ...', Journal of the Chemical Society, Dalton Transactions, no. 3, pp. 814-821. https://doi.org/10.1039/DT9810000814

Metallocene derivatives of early transition elements. Part 3. Synthesis, characterisation, conformation, and rotational barriers [for the Zr-C(sp³) bond] of the zirconium(IV) complexes [Zr(η-C₅H₄R)₂{CH-(SiMe₃) ₂}Cl] and the crystal and ... / Lappert, Michael F.; Riley, Paul I.; Yarrow, Paul I.W. et al.
In: Journal of the Chemical Society, Dalton Transactions, No. 3, 1981, p. 814-821.

Research output: Contribution to journal › Article › peer-review

TY - JOUR

T1 - Metallocene derivatives of early transition elements. Part 3. Synthesis, characterisation, conformation, and rotational barriers [for the Zr-C(sp3) bond] of the zirconium(IV) complexes [Zr(η-C5H4R)2{CH-(SiMe3) 2}Cl] and the crystal and ...

AU - Lappert, Michael F.

AU - Riley, Paul I.

AU - Yarrow, Paul I.W.

AU - Atwood, Jerry L.

AU - Hunter, William E.

AU - Zaworotko, Michael J.

PY - 1981

Y1 - 1981

N2 - full title: Metallocene derivatives of early transition elements. Part 3. Synthesis, characterisation, conformation, and rotational barriers [for the Zr-C(sp3) bond] of the zirconium(IV) complexes [Zr(η-C5H4R)2{CH-(SiMe3) 2}Cl] and the crystal and molecular structures of the t-butyl and trimethylsilyl complexes (R = CMe3 or SiMe3) The complexes [Zr(η-C5H4R)2{CH(SiMe3) 2}Cl] have been prepared from the appropriate metallocene dichloride (R = Me, Et, Pri, But, or SiMe3) and an equimolar portion of Li[CH(SiMe3)2] in diethyl ether. [The same method failed to yield the hafnium analogues (for R = H or SiMe3).] Except for R = Et, these are white or pale yellow sharp-melting crystalline solids which have been characterised by elemental analysis and i.r., 1H, and 13C n.m.r. spectra. Variable-temperature 1H n.m.r. spectra show that (i) at low temperature (coalescence temperature, Tc, -4 to 18 °C) the preferred conformation has diastereotopic pairs of SiMe3 [of CH(SiMe3)2] and η-C5H4R groups, and (ii) ΔG‡ for rotation about the Zr-C(sp3) bond is in the range 59.8 to 65.6 kJ mol-1 (R = SiMe3 > Et > But > Pri ≈ Me > H). The ring cyclopentadienyl 13C n.m.r. signals are each split into a doublet at -30 °C but are observed as three distinct sharp singlets at 60 °C. The compounds [Zr(η-C5H4R)2{CH(SiMe3) 2}Cl] (R = But or SiMe3) are isostructural, crystallising in the space group P21/n, with cell constants, for Z = 4, being a = 10.496(6), b = 15.250(8), c = 18.272(9) Å, β = 100.48(5)° for R = But, and a = 10.525(5), b = 15.320(7), c = 19.064(8) Å, β = 98.73(4)° for R = SiMe3. There is considerable strain within the substitued cyclopentadienyl ligands, as exemplified by the distinct spread in the range of Zr-C(π) distances and the significant deviation from the cyclopentadienyl plane of the-XMe3 moiety. The remainder of the molecule, however, does not seem to be influenced by any steric constraints with the Zr-Cl bonds, of 2.452(2) and 2.447(1) Å (for X = C and Si respectively), and the Zr-C(σ) bonds, of 2.324(8) and 2.327(3) Å, being within previously observed limits. The conformation in the crystal corresponds to that found by low-temperature n.m.r. spectroscopy.

AB - full title: Metallocene derivatives of early transition elements. Part 3. Synthesis, characterisation, conformation, and rotational barriers [for the Zr-C(sp3) bond] of the zirconium(IV) complexes [Zr(η-C5H4R)2{CH-(SiMe3) 2}Cl] and the crystal and molecular structures of the t-butyl and trimethylsilyl complexes (R = CMe3 or SiMe3) The complexes [Zr(η-C5H4R)2{CH(SiMe3) 2}Cl] have been prepared from the appropriate metallocene dichloride (R = Me, Et, Pri, But, or SiMe3) and an equimolar portion of Li[CH(SiMe3)2] in diethyl ether. [The same method failed to yield the hafnium analogues (for R = H or SiMe3).] Except for R = Et, these are white or pale yellow sharp-melting crystalline solids which have been characterised by elemental analysis and i.r., 1H, and 13C n.m.r. spectra. Variable-temperature 1H n.m.r. spectra show that (i) at low temperature (coalescence temperature, Tc, -4 to 18 °C) the preferred conformation has diastereotopic pairs of SiMe3 [of CH(SiMe3)2] and η-C5H4R groups, and (ii) ΔG‡ for rotation about the Zr-C(sp3) bond is in the range 59.8 to 65.6 kJ mol-1 (R = SiMe3 > Et > But > Pri ≈ Me > H). The ring cyclopentadienyl 13C n.m.r. signals are each split into a doublet at -30 °C but are observed as three distinct sharp singlets at 60 °C. The compounds [Zr(η-C5H4R)2{CH(SiMe3) 2}Cl] (R = But or SiMe3) are isostructural, crystallising in the space group P21/n, with cell constants, for Z = 4, being a = 10.496(6), b = 15.250(8), c = 18.272(9) Å, β = 100.48(5)° for R = But, and a = 10.525(5), b = 15.320(7), c = 19.064(8) Å, β = 98.73(4)° for R = SiMe3. There is considerable strain within the substitued cyclopentadienyl ligands, as exemplified by the distinct spread in the range of Zr-C(π) distances and the significant deviation from the cyclopentadienyl plane of the-XMe3 moiety. The remainder of the molecule, however, does not seem to be influenced by any steric constraints with the Zr-Cl bonds, of 2.452(2) and 2.447(1) Å (for X = C and Si respectively), and the Zr-C(σ) bonds, of 2.324(8) and 2.327(3) Å, being within previously observed limits. The conformation in the crystal corresponds to that found by low-temperature n.m.r. spectroscopy.

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U2 - 10.1039/DT9810000814

DO - 10.1039/DT9810000814

M3 - Article

AN - SCOPUS:51149221987

SN - 1472-7773

SP - 814

EP - 821

JO - Journal of the Chemical Society, Dalton Transactions

JF - Journal of the Chemical Society, Dalton Transactions

IS - 3

ER -