Jump to main content
Jump to site search


Rapid reversible borane to boryl hydride exchange by metal shuttling on the carborane cluster surface

Author affiliations

Abstract

In this work, we introduce a novel concept of a borane group vicinal to a metal boryl bond acting as a supporting hemilabile ligand in exohedrally metalated three-dimensional carborane clusters. The (POBOP)Ru(Cl)(PPh3) pincer complex (POBOP = 1,7-OP(i-Pr)2-m-2-carboranyl) features extreme distortion of the two-center-two-electron Ru–B bond due to the presence of a strong three-center-two-electron B–H⋯Ru vicinal interaction. Replacement of the chloride ligand with a hydride afforded the (POBOP)Ru(H)(PPh3) pincer complex, which possesses B–Ru, B–H⋯Ru, and Ru–H bonds. This complex was found to exhibit a rapid exchange between hydrogen atoms of the borane and the terminal hydride through metal center shuttling between two boron atoms of the carborane cage. This exchange process, which involves sequential cleavage and formation of strong covalent metal–boron and metal–hydrogen bonds, is unexpectedly facile at temperatures above −50 °C corresponding to an activation barrier of 12.2 kcal mol−1. Theoretical calculations suggested two equally probable pathways for the exchange process through formally Ru(0) or Ru(IV) intermediates, respectively. The presence of this hemilabile vicinal B–H⋯Ru interaction in (POBOP)Ru(H)(PPh3) was found to stabilize a latent coordination site at the metal center promoting efficient catalytic transfer dehydrogenation of cyclooctane under nitrogen and air at 170 °C.

Graphical abstract: Rapid reversible borane to boryl hydride exchange by metal shuttling on the carborane cluster surface

Back to tab navigation

Supplementary files

Publication details

The article was received on 26 Apr 2017, accepted on 24 May 2017 and first published on 25 May 2017


Article type: Edge Article
DOI: 10.1039/C7SC01846K
Citation: Chem. Sci., 2017, Advance Article
  • Open access: Creative Commons BY-NC license
  •   Request permissions

    Rapid reversible borane to boryl hydride exchange by metal shuttling on the carborane cluster surface

    B. J. Eleazer, M. D. Smith, A. A. Popov and D. V. Peryshkov, Chem. Sci., 2017, Advance Article , DOI: 10.1039/C7SC01846K

    This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material and it is not used for commercial purposes.

    Reproduced material should be attributed as follows:

    • For reproduction of material from NJC:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
    • For reproduction of material from PCCP:
      [Original citation] - Published by the PCCP Owner Societies.
    • For reproduction of material from PPS:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
    • For reproduction of material from all other RSC journals:
      [Original citation] - Published by The Royal Society of Chemistry.

    Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.

Search articles by author

Spotlight

Advertisements