Jump to main content
Jump to site search
PLANNED MAINTENANCE Close the message box

Scheduled maintenance upgrade on Thursday 4th of May 2017 from 8.00am to 9.00am (BST).

During this time our websites will be offline temporarily. If you have any questions please use the feedback button on this page. We apologise for any inconvenience this might cause and thank you for your patience.


Issue 42, 2016
Previous Article Next Article

Dehalogenation of chloroalkanes by nickel(I) porphyrin derivatives, a computational study

Author affiliations

Abstract

The nickel(I) octaethylisobacteriochlorin anion ([OEiBCh-Ni(I)]) is commonly used as a synthetic model of cofactor F430 from Methyl-Coenzyme M Reductase. In this regard, experimental studies show that [OEiBCh-Ni(I)] can catalyze dehalogenation of aliphatic halides in DMF solution by a highly efficient SN2 reaction. To better understand this process, we constructed theoretical models of the dehalogenation of chloromethane by a simple nickel(I) isobacteriochlorin anion and compared its reactivity with that of similar Ni(I) complexes with other porphyrin-derived ligands: porphyrin, chlorin, bactreriochlorin, hexahydroporphyrin and octahydroporphyrin. Our calculations predict that all of the porphyrin derivative's model reactions proceed through low-spin complexes. Relative to the energy of the separate reactants the theoretical activation energies (free-energy barriers with solvation corrections) for the dehalogenation of chloromethane are similar for all of the porphyrin derivatives and range for the different functionals from 10–15 kcal mol−1 for B3LYP to 5–10 kcal mol−1 for M06-L and to 13–18 kcal mol−1 for ωB97X-D. The relative free energies of the products of the dehalogenation step, L-Ni–Me adducts, have a range from −5 to −40 kcal mol−1 for all functionals; generally becoming more negative with increasing saturation of the porphyrin ligand. Moreover, no significant differences in the theoretical chlorine kinetic isotope effect were discernable with change of porphyrin ligand.

Graphical abstract: Dehalogenation of chloroalkanes by nickel(i) porphyrin derivatives, a computational study

Back to tab navigation
Please wait while Download options loads

Supplementary files

Publication details

The article was received on 01 Jul 2016, accepted on 19 Sep 2016 and first published on 20 Sep 2016


Article type: Paper
DOI: 10.1039/C6DT02632J
Citation: Dalton Trans., 2016,45, 16869-16877
  • Open access: Creative Commons BY license
  •   Request permissions

    Dehalogenation of chloroalkanes by nickel(I) porphyrin derivatives, a computational study

    L. Szatkowski and M. B. Hall, Dalton Trans., 2016, 45, 16869
    DOI: 10.1039/C6DT02632J

    This article is licensed under a Creative Commons Attribution 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.

    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