Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 26, 2019
Previous Article Next Article

Use of 15N NMR spectroscopy to probe covalency in a thorium nitride

Author affiliations

Abstract

Reaction of the thorium metallacycle, [Th{N(R)(SiMe2)CH2}(NR2)2] (R = SiMe3) with 1 equiv. of NaNH2 in THF, in the presence of 18-crown-6, results in formation of the bridged thorium nitride complex, [Na(18-crown-6)(Et2O)][(R2N)3Th(μ-N)(Th(NR2)3] ([Na][1]), which can be isolated in 66% yield after work-up. Complex [Na][1] is the first isolable molecular thorium nitride complex. Mechanistic studies suggest that the first step of the reaction is deprotonation of [Th{N(R)(SiMe2)CH2}(NR2)2] by NaNH2, which results in formation of the thorium bis(metallacycle) complex, [Na(THF)x][Th{N(R)(SiMe2CH2)}2(NR2)], and NH3. NH3 then reacts with unreacted [Th{N(R)(SiMe2)CH2}(NR2)2], forming [Th(NR2)3(NH2)] (2), which protonates [Na(THF)x][Th{N(R)(SiMe2CH2)}2(NR2)] to give [Na][1]. Consistent with hypothesis, addition of excess NH3 to a THF solution of [Th{N(R)(SiMe2)CH2}(NR2)2] results in formation of [Th(NR2)3(NH2)] (2), which can be isolated in 51% yield after work-up. Furthermore, reaction of [K(DME)][Th{N(R)(SiMe2CH2)}2(NR2)] with 2, in THF-d8, results in clean formation of [K][1], according to 1H NMR spectroscopy. The electronic structures of [1] and 2 were investigated by 15N NMR spectroscopy and DFT calculations. This analysis reveals that the Th–Nnitride bond in [1] features more covalency and a greater degree of bond multiplicity than the Th–NH2 bond in 2. Similarly, our analysis indicates a greater degree of covalency in [1]vs. comparable thorium imido and oxo complexes.

Graphical abstract: Use of 15N NMR spectroscopy to probe covalency in a thorium nitride

Back to tab navigation

Supplementary files

Article information


Submitted
19 Apr 2019
Accepted
02 Jun 2019
First published
04 Jun 2019

This article is Open Access
All publication charges for this article have been paid for by the Royal Society of Chemistry

Chem. Sci., 2019,10, 6431-6436
Article type
Edge Article

Use of 15N NMR spectroscopy to probe covalency in a thorium nitride

S. L. Staun, D. Sergentu, G. Wu, J. Autschbach and T. W. Hayton, Chem. Sci., 2019, 10, 6431
DOI: 10.1039/C9SC01960J

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.


Social activity

Search articles by author

Spotlight

Advertisements