Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2013 Jul 13:58:179-189.
doi: 10.1016/j.poly.2013.01.043.

Sulfide Oxidation by O2: Synthesis, Structure and Reactivity of Novel Sulfide-Incorporated Fe(II) Bis(imino)pyridine Complexes

Leland R Widger  1 , Maxime A Siegler, David P Goldberg
Affiliations

Sulfide Oxidation by O2: Synthesis, Structure and Reactivity of Novel Sulfide-Incorporated Fe(II) Bis(imino)pyridine Complexes

Leland R Widger et al. Polyhedron. .

Abstract

The unsymmetrical iron(II) bis(imino)pyridine complexes [FeII(LN3SMe)(H2O)3](OTf)2 (1), and [FeII(LN3SMe)Cl2] (2) were synthesized and their reactivity with O2 was examined. Complexes 1 and 2 were characterized by single crystal X-ray crystallography, LDI-MS, 1H-NMR and elemental analysis. The LN3SMe ligand was designed to incorporate a single sulfide donor and relies on the bis(imino)pyridine scaffold. This scaffold was selected for its ease of synthesis and its well-precedented ability to stabilize Fe(II) ions. Complexes 1 and 2 ware prepared via a metal-assisted template reaction from the unsymmetrical pyridyl ketone precursor 2-(O=CMe)-6-(2,6-(iPr2-C6H3N=CMe)-C5H3N. Reaction of 1 with O2 was shown to afford the S-oxygenated sulfoxide complex [Fe(LN3S(O)Me)(OTf)]2+(3), whereas compound 2, under the same reaction conditions, afforded the corresponding sulfone complex [Fe(LN3S(O2)Me)Cl]2+ (4).

Keywords: bis(imino)pyridine; dioxygen; iron(II); sulfide; sulfone; sulfoxide.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Oxidation of cysteine to cysteine sulfinic acid by CDO.
Fig. 2
Fig. 2
Examples of sulfoxides in synthetic chemistry and detoxification processes.
Fig. 3
Fig. 3
Proposed catalytic mechanism of aerobic sulfoxidation by NOx species [61].
Fig. 4
Fig. 4
Displacement ellipsoid plot (50% probability level) of the cation of 1. H-atoms are removed for clarity.
Fig. 5
Fig. 5
Displacement ellipsoid plot (50% probability level) of 2. H-atoms are removed for clarity.
Fig. 6
Fig. 6
Hydrogen bonding network in the crystal lattice of 1. Disorder and H-atoms were removed for clarity.
Fig. 7
Fig. 7
Reaction of 1 with excess O2 in CH2Cl2 at 60 °C as monitored by LDI-MS. The peak at m/z 648.1 is assigned to [1 − 3H2O − OTf]+, and the peak at m/z 664.4 is assigned to [Fe(LN3S(O)Me)(OTf)]+.
Fig. 8
Fig. 8
Reaction of 2 with excess O2 in CH2Cl2 at 60 °C as monitored by LDI-MS. The peak at m/z 534.4 is assigned to [2 – Cl]+, and the peak at m/z 566.4 is assigned to doubly-oxygenated [Fe(LN3S(O2)Me)Cl]+. The small peak at m/z 550.4 is assigned to singly-oxygenated [Fe(LN3S(O)Me)Cl]+.
Fig. 9
Fig. 9
1H-NMR spectrum of 2-(methylsulfinyl)aniline recovered following demetalation of 3.
Fig. 10
Fig. 10
1H-NMR spectrum of the crude mixture following demetalation of 4. The 2-(methylsulfonyl)aniline is identified at 3.06 ppm, with minor peaks arising from the intermediate sulfoxide (2.92 ppm) and starting sulfide (2.36 ppm).
Scheme 1
Scheme 1
Synthesis of complex 1.
Scheme 2
Scheme 2
Synthesis of complex 2.
Scheme 3
Scheme 3
Reaction of 1 with O2 to form sulfoxide complex 3.
Scheme 4
Scheme 4
Reaction of 2 with O2 to form the sulfone complex 4.
Scheme 5
Scheme 5
Hydrolysis of bis(imino)pyridine complexes.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Bollinger JM, Jr, Krebs C. J Inorg Biochem. 2006;100:586. - PubMed
    1. Solomon EI, Brunold TC, Davis MI, Kemsley JN, Lee SK, Lehnert N, Neese F, Skulan AJ, Yang YS. J Zhou, Chem Rev. 2000;100:235. - PubMed
    1. Costas M, Mehn MP, Jensen MP, Que L., Jr Chem Rev. 2004;104:939. - PubMed
    1. Koehntop KD, Emerson JP, Que L., Jr J Biol Inorg Chem. 2005;10:87. - PubMed
    1. Neidig ML, Solomon EI. Chem Commun. 2005:5843. - PubMed

LinkOut - more resources