Tetrabenzylzirconium

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Tetrabenzylzirconium
ZrBn4.svg
Identifiers
3D model (JSmol)
ChemSpider
  • InChI=1S/4C7H7.Zr/c4*1-7-5-3-2-4-6-7;/h4*2-6H,1H2;/q4*-1;+4
    Key: QSLMQGXOMLSFAW-UHFFFAOYSA-N
  • [CH2-]C1=CC=CC=C1.[CH2-]C1=CC=CC=C1.[CH2-]C1=CC=CC=C1.[CH2-]C1=CC=CC=C1.[Zr+4]
Properties
C28H28Zr
Molar mass 455.756 g·mol−1
Appearance orange solid
Density 1.34-1.39 g/cm3[1]
Melting point 133–134 °C (271–273 °F; 406–407 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Tetrabenzylzirconium is an organozirconium compound with the formula Zr(CH2C6H5)4. The molecule features diamagnetic Zr(IV) bonded to four benzyl ligands. It is an orange air- and photo-sensitive solid, which is soluble in hydrocarbon solvents. The compound is a precursor to catalysts for the polymerization of olefins.[2] [3]

Structure, synthesis, reactions[edit]

Structure of tetrabenzylzirconium as determined by X-ray crystallography, with H atoms omitted for clarity.[1]

X-ray crystallography demonstrates that the benzyl ligands are highly flexible: one polymorph features four η2-ligands, whereas another has two η1- and two η2-benzyl ligands.[1]

The compound is prepared by combining benzylmagnesium chloride and zirconium tetrachloride in diethyl ether.[4]

Tetrabenzylzirconium readily undergoes protonolysis, e.g. with hydrogen chloride:

Zr(CH2C6H5)4 + HCl → Zr(CH2C6H5)3Cl + CH3C6H5

See also[edit]

  • Tetrabenzyltitanium (RN = 17520-19-3)[5]

References[edit]

  1. ^ a b c Rong, Yi; Al-Harbi, Ahmed; Parkin, Gerard (2012). "Highly Variable Zr–CH2–Ph Bond Angles in Tetrabenzylzirconium: Analysis of Benzyl Ligand Coordination Modes". Organometallics. 31 (23): 8208–8217. doi:10.1021/om300820b.
  2. ^ Tshuva, Edit Y.; Goldberg, Israel; Kol, Moshe (2000). "Isospecific Living Polymerization of 1-Hexene by a Readily Available Nonmetallocene C2-Symmetrical Zirconium Catalyst". Journal of the American Chemical Society. 122 (43): 10706–10707. doi:10.1021/ja001219g.
  3. ^ Zucchini, U.; Albizzati, E.; Giannini, U. (1971). "Synthesis and Properties of Some Titanium and Zirconium Benzyl Derivatives". Journal of Organometallic Chemistry. 26: 357–372. doi:10.1016/S0022-328X(00)82618-2.
  4. ^ Mashima, Kazushi; Tsurugi, Hatato (2013). "Tetrabenzylzirconium". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rn01555. ISBN 978-0471936237.
  5. ^ Davies, Gwyneth R.; Jarvis, J. A. J.; Kilbourn, B. T. (1971). "The Crystal and Molecular Structures (At –40 °C) of the Tetrabenzyls of Titanium, Hafnium, and Tin". J. Chem. Soc. D (23): 1511–1512. doi:10.1039/C29710001511.