Selectivity of Rh⋅⋅⋅H−C Binding in a σ-Alkane Complex Controlled by the Secondary Microenvironment in the Solid State

Samantha K. Furfari, Bengt E. Tegner, Arron L. Burnage, Laurence R. Doyle, Alexander J. Bukvic, Stuart A. Macgregor, Andrew S. Weller*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

By using single-crystal to single-crystal solid-state molecular organometallic (SMOM) techniques, the σ -alkane complex [Rh( t Bu 2 PCH 2 CH 2 CH 2 P t Bu 2 )( η 2 , η 2 -C 7 H 12 )][BAr F 4 ] (Ar F = 3,5-(CF 3 ) 2 C 6 H 3 ) is synthesized and structurally characterized, in which the alkane (norbornane) binds through two exo -C-H···Rh interactions. In contrast, the bis-cyclohexyl phosphine analogue shows endo -alkane binding. Comparison of the two systems, supported by periodic DFT calculations, NCI plots and Hirshfeld surface analyses, trace this different regioselectivity to subtle changes in the local microenvironment surrounding the alkane ligand. A tertiary periodic structure supporting a secondary microenvironment that controls binding at the metal site has parallels with enzymes. The new σ -alkane complex is also a catalyst for solid/gas 1-butene isomerization, and catalyst resting states are identified for this.

Original languageEnglish
Pages (from-to)3177-3183
Number of pages7
JournalChemistry : A European Journal
Volume27
Issue number9
Early online date12 Jan 2021
DOIs
Publication statusE-pub ahead of print - 12 Jan 2021

Bibliographical note

Funding Information:
We are grateful to SCG Chemicals, the EPSRC (M024210) and the Leverhulme Trust (RPG‐2015‐447) for funding; Professor Neil Champness (University of Nottingham, UK) for useful discussions and alerting us to the use of CrystalExplorer to explore weak interactions in the solid state; and Dr José Manuel Menéndez (Heriot‐Watt) for excellent IT support.

Publisher Copyright:
© 2020 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH

Keywords

  • density functional calculations
  • isomerization
  • periodic DFT
  • rhodium
  • selectivity
  • SMOM

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