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Understanding hydrogen sulfide storage: probing conditions for sulfide release from hydrodisulfides.

Bailey TS, Zakharov LN, Pluth MD - J. Am. Chem. Soc. (2014)

Bottom Line: Once generated, H2S can be oxidized to generate reductant-labile sulfane sulfur pools, which include hydrodisulfides/persulfides.We report here the synthesis, isolation, and characterization (NMR, IR, Raman, HRMS, X-ray) of a small-molecule hydrodisulfide and highlight its reactivity with reductants, nucleophiles, electrophiles, acids, and bases.Our experimental results establish that hydrodisulfides release H2S upon reduction and that deprotonation results in disproportionation to the parent thiol and S(0), thus providing a mechanism for transsulfuration in the sulfane sulfur pool.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and Biochemistry, Institute of Molecular Biology, Material Science Institute, 1253 University of Oregon , Eugene, Oregon 97403, United States.

ABSTRACT
Hydrogen sulfide (H2S) is an important biological signaling agent that exerts action on numerous (patho)physiological processes. Once generated, H2S can be oxidized to generate reductant-labile sulfane sulfur pools, which include hydrodisulfides/persulfides. Despite the importance of hydrodisulfides in H2S storage and signaling, little is known about the physical properties or chemical reactivity of these compounds. We report here the synthesis, isolation, and characterization (NMR, IR, Raman, HRMS, X-ray) of a small-molecule hydrodisulfide and highlight its reactivity with reductants, nucleophiles, electrophiles, acids, and bases. Our experimental results establish that hydrodisulfides release H2S upon reduction and that deprotonation results in disproportionation to the parent thiol and S(0), thus providing a mechanism for transsulfuration in the sulfane sulfur pool.

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(a) X-ray crystal structure of TrtSSH. Thermal ellipsoids are drawnat the 50% probability level. Hydrogen atoms on the phenyl rings areomitted for clarity. Full crystallographic details are available inthe Supporting Information. (b) Infrared(black) and Raman (blue) spectra of TrtSH (top) and TrtSSH (bottom).The Raman spectrum of S8 (red) is shown for comparison.
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fig1: (a) X-ray crystal structure of TrtSSH. Thermal ellipsoids are drawnat the 50% probability level. Hydrogen atoms on the phenyl rings areomitted for clarity. Full crystallographic details are available inthe Supporting Information. (b) Infrared(black) and Raman (blue) spectra of TrtSH (top) and TrtSSH (bottom).The Raman spectrum of S8 (red) is shown for comparison.

Mentions: With TrtSSH in hand, we fully characterizedthe compound and comparedits chemical properties to those of TrtSH. Both the 1Hand 13C{1H} NMR spectra of TrtSSH are similarto those of TrtSH, but the 1H NMR resonance of the sulfhydrylSSH is shifted upfield to 2.7 ppm, by comparison to 3.1 ppm in TrtSH(Figures S4, S5). Much of the infraredand Raman spectra of TrtSSH and TrtSH are also similar due to theirrelated structures; however, the S–H stretch shifts to a lowerwavenumber by 65 cm–1 for TrtSSH when compared toTrtSH (Figure 1b). Comparison of the Ramanspectrum of TrtSSH with that of S8 showed similaritiesin the 200–500 cm–1 region correspondingsulfur–sulfur bond formation. HRMS analysis of TrtSSH confirmedits atomic composition, affording an m/z value of 307.0631 amu, which agrees well with the calculated valueof 307.0621 amu for TrtSS–. To further confirm themolecular structure of TrtSSH, single crystals suitable for X-raydiffraction were grown from toluene/Et2O. TrtSSH crystallizesin P212121 withan S–S bond length of 2.0396(12) Å and a CSSH dihedralangle of 82.2°, both of which are within the ranges common fordisulfides (Figure 1a). The terminal −SSHhydrogen was located from the residual density map, and inspectionof the packing diagram shows that it does not form hydrogen bondswith other atoms in the solid state (Figure S28).


Understanding hydrogen sulfide storage: probing conditions for sulfide release from hydrodisulfides.

Bailey TS, Zakharov LN, Pluth MD - J. Am. Chem. Soc. (2014)

(a) X-ray crystal structure of TrtSSH. Thermal ellipsoids are drawnat the 50% probability level. Hydrogen atoms on the phenyl rings areomitted for clarity. Full crystallographic details are available inthe Supporting Information. (b) Infrared(black) and Raman (blue) spectra of TrtSH (top) and TrtSSH (bottom).The Raman spectrum of S8 (red) is shown for comparison.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4120993&req=5

fig1: (a) X-ray crystal structure of TrtSSH. Thermal ellipsoids are drawnat the 50% probability level. Hydrogen atoms on the phenyl rings areomitted for clarity. Full crystallographic details are available inthe Supporting Information. (b) Infrared(black) and Raman (blue) spectra of TrtSH (top) and TrtSSH (bottom).The Raman spectrum of S8 (red) is shown for comparison.
Mentions: With TrtSSH in hand, we fully characterizedthe compound and comparedits chemical properties to those of TrtSH. Both the 1Hand 13C{1H} NMR spectra of TrtSSH are similarto those of TrtSH, but the 1H NMR resonance of the sulfhydrylSSH is shifted upfield to 2.7 ppm, by comparison to 3.1 ppm in TrtSH(Figures S4, S5). Much of the infraredand Raman spectra of TrtSSH and TrtSH are also similar due to theirrelated structures; however, the S–H stretch shifts to a lowerwavenumber by 65 cm–1 for TrtSSH when compared toTrtSH (Figure 1b). Comparison of the Ramanspectrum of TrtSSH with that of S8 showed similaritiesin the 200–500 cm–1 region correspondingsulfur–sulfur bond formation. HRMS analysis of TrtSSH confirmedits atomic composition, affording an m/z value of 307.0631 amu, which agrees well with the calculated valueof 307.0621 amu for TrtSS–. To further confirm themolecular structure of TrtSSH, single crystals suitable for X-raydiffraction were grown from toluene/Et2O. TrtSSH crystallizesin P212121 withan S–S bond length of 2.0396(12) Å and a CSSH dihedralangle of 82.2°, both of which are within the ranges common fordisulfides (Figure 1a). The terminal −SSHhydrogen was located from the residual density map, and inspectionof the packing diagram shows that it does not form hydrogen bondswith other atoms in the solid state (Figure S28).

Bottom Line: Once generated, H2S can be oxidized to generate reductant-labile sulfane sulfur pools, which include hydrodisulfides/persulfides.We report here the synthesis, isolation, and characterization (NMR, IR, Raman, HRMS, X-ray) of a small-molecule hydrodisulfide and highlight its reactivity with reductants, nucleophiles, electrophiles, acids, and bases.Our experimental results establish that hydrodisulfides release H2S upon reduction and that deprotonation results in disproportionation to the parent thiol and S(0), thus providing a mechanism for transsulfuration in the sulfane sulfur pool.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and Biochemistry, Institute of Molecular Biology, Material Science Institute, 1253 University of Oregon , Eugene, Oregon 97403, United States.

ABSTRACT
Hydrogen sulfide (H2S) is an important biological signaling agent that exerts action on numerous (patho)physiological processes. Once generated, H2S can be oxidized to generate reductant-labile sulfane sulfur pools, which include hydrodisulfides/persulfides. Despite the importance of hydrodisulfides in H2S storage and signaling, little is known about the physical properties or chemical reactivity of these compounds. We report here the synthesis, isolation, and characterization (NMR, IR, Raman, HRMS, X-ray) of a small-molecule hydrodisulfide and highlight its reactivity with reductants, nucleophiles, electrophiles, acids, and bases. Our experimental results establish that hydrodisulfides release H2S upon reduction and that deprotonation results in disproportionation to the parent thiol and S(0), thus providing a mechanism for transsulfuration in the sulfane sulfur pool.

Show MeSH