Research Article

Investigation of structure and dynamics in the sodium metallocenes CpNa and CpNa·THF via solid-state NMR, X-ray diffraction and computational modelling

  1. Cory M. Widdifield,
  2. Joel A. Tang,
  3. Charles L. B. Macdonald,
  4. Robert W. Schurko*

Article first published online: 3 JAN 2008

DOI: 10.1002/mrc.2124

Issue

Magnetic Resonance in Chemistry

Magnetic Resonance in Chemistry

Special Issue: New techniques in solid-state NMR

Volume 45, Issue S1, pages S116–S128, December 2007

Additional Information

How to Cite

Widdifield, C. M., Tang, J. A., Macdonald, C. L. B. and Schurko, R. W. (2007), Investigation of structure and dynamics in the sodium metallocenes CpNa and CpNa·THF via solid-state NMR, X-ray diffraction and computational modelling. Magn. Reson. Chem., 45: S116–S128. doi: 10.1002/mrc.2124

Author Information

  1. Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada N9B 3P4

*Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada N9B 3P4.

Publication History

  1. Issue published online: 3 JAN 2008
  2. Article first published online: 3 JAN 2008
  3. Manuscript Accepted: 24 SEP 2007
  4. Manuscript Revised: 18 SEP 2007
  5. Manuscript Received: 16 JUL 2007

Funded by

  • Imperial Oil
  • Natural Sciences and Engineering Research Council (NSERC)
  • Canadian Foundation for Innovation (CFI)
  • Ontario Innovation Trust (OIT)
  • University of Windsor
  • Centre for Catalysis and Materials Research (CCMR)

SEARCH

SEARCH BY CITATION

ARTICLE TOOLS

Get PDF (563K)

Keywords:

  • solid-state NMR;
  • 13C NMR;
  • 23Na NMR;
  • metallocenes;
  • ab initio;
  • chemical shielding;
  • CSA;
  • EFG;
  • XRD;
  • CP/MAS

Abstract

Solid-state 23Na NMR spectra of two organometallic complexes, cyclopentadienylsodium (CpNa) and the tetrahydrofuran (THF) solvate of CpNa (CpNa·THF), are presented. Analytical simulations of experimental spectra and calculated 23Na electric-field gradient (EFG) tensors confirm that both complexes are present in microcrystalline samples of CpNa recrystallized from THF. For the solvate, 23Na NMR experiments at 9.4 T and 11.7 T elucidate sodium chemical shielding (CS) tensor parameters, and establish that the EFG and CS tensor frames are non-coincident. Single-crystal X-ray diffraction (XRD) experiments are used to determine the crystal structure of CpNa·THF: Cmca (a = 9.3242(15) Å, b = 20.611(3) Å, c = 9.8236(14) Å, α = β = γ = 90° , V = 1887.9(5)Å3, Z = 8). For CpNa, 23Na NMR data acquired at multiple field strengths establish sodium CS tensor parameters more precisely than in previous reports. Variable-temperature (VT) powder XRD (pXRD) experiments determine the temperature dependence of the CpNa unit cell parameters. The combination of 23Na quadrupolar NMR parameters, pXRD data and calculations of 23Na EFG tensors is used to examine various models of dynamic motion in the solid state. It is proposed that the sodium atom in CpNa undergoes an anisotropic, temperature-dependent, low frequency motion within the ab crystallographic plane, in contrast with previous models. Copyright © 2007 John Wiley & Sons, Ltd.

Get PDF (563K)