Jump to main content
Jump to site search

Issue 16, 2017
Previous Article Next Article

Large, weakly basic bis(carboranyl)phosphines: an experimental and computational study

Author affiliations

Abstract

The bis(carboranyl)phosphines [μ-2,2′-PPh-{1-(1′-1′,2′-closo-C2B10H10)-1,2-closo-C2B10H10}] (I) and [μ-2,2′-PEt-{1-(1′-1′,2′-closo-C2B10H10)-1,2-closo-C2B10H10}] (1) have been prepared and spectroscopically and structurally characterised. Crystallographic and DFT computational studies of 1 suggest that the orientation of the ethyl group, relative to the bis(carborane), is the result of intramolecular dihydrogen bonding. This orientation is such that the magnitudes of the 2JPH coupling constants are approximately equal but of opposite sign, and fast exchange between the methylene protons in solution leads to an observed 2JPH close to zero. The steric properties of I, 1 and their derivatives [μ-2,2′-P(Ph)AuCl-{1-(1′-1′,2′-closo-C2B10H10)-1,2-closo-C2B10H10}] (2) and [μ-2,2′-P(Et)AuCl-{1-(1′-1′,2′-closo-C2B10H10)-1,2-closo-C2B10H10}] (3) have been assessed by Tolman cone angle and percent buried volume calculations, from which it is concluded that the bis(carboranyl)phosphines I and 1 are comparable to PCy3 in their steric demands. The selenides [μ-2,2′-P(Ph)Se-{1-(1′-1′,2′-closo-C2B10H10)-1,2-closo-C2B10H10}] (4) and [μ-2,2′-P(Et)Se-{1-(1′-1′,2′-closo-C2B10H10)-1,2-closo-C2B10H10}] (5) have also been prepared and characterised. The 1JPSe coupling constants for 4 and 5 are the largest reported so far for carboranylphosphine selenides and indicate that I and 1 are very weakly basic.

Graphical abstract: Large, weakly basic bis(carboranyl)phosphines: an experimental and computational study

Back to tab navigation
Please wait while Download options loads

Supplementary files

Publication details

The article was received on 08 Feb 2017, accepted on 06 Mar 2017 and first published on 07 Mar 2017


Article type: Paper
DOI: 10.1039/C7DT00485K
Citation: Dalton Trans., 2017,46, 5218-5228
  •   Request permissions

    Large, weakly basic bis(carboranyl)phosphines: an experimental and computational study

    L. E. Riley, T. Krämer, C. L. McMullin, D. Ellis, G. M. Rosair, I. B. Sivaev and A. J. Welch, Dalton Trans., 2017, 46, 5218
    DOI: 10.1039/C7DT00485K

Search articles by author