TY - JOUR
T1 - Reactions of CH 3SH and CH 3SSCH 3 with gas-phase hydrated radical anions (H 2O) n •-, CO 2 •-(H 2O) n, and O 2 •-(H 2O) n
AU - Höckendorf, Robert F.
AU - Hao, Qiang
AU - Sun, Zheng
AU - Fox-Beyer, Brigitte S.
AU - Cao, Yali
AU - Balaj, O. Petru
AU - Bondybey, Vladimir E.
AU - Siu, Chi Kit
AU - Beyer, Martin K.
PY - 2012/4/19
Y1 - 2012/4/19
N2 - The chemistry of (H 2O) n •-, CO 2 •-(H 2O) n, and O 2 •-(H 2O) n with small sulfur-containing molecules was studied in the gas phase by Fourier transform ion cyclotron resonance mass spectrometry. With hydrated electrons and hydrated carbon dioxide radical anions, two reactions with relevance for biological radiation damage were observed, cleavage of the disulfide bond of CH 3SSCH 3 and activation of the thiol group of CH 3SH. No reactions were observed with CH 3SCH 3. The hydrated superoxide radical anion, usually viewed as major source of oxidative stress, did not react with any of the compounds. Nanocalorimetry and quantum chemical calculations give a consistent picture of the reaction mechanism. The results indicate that the conversion of e - and CO 2 •- to O 2 •- deactivates highly reactive species and may actually reduce oxidative stress. For reactions of (H 2O) n •- with CH 3SH as well as CO 2 •-(H 2O) n with CH 3SSCH 3, the reaction products in the gas phase are different from those reported in the literature from pulse radiolysis studies. This observation is rationalized with the reduced cage effect in reactions of gas-phase clusters.
AB - The chemistry of (H 2O) n •-, CO 2 •-(H 2O) n, and O 2 •-(H 2O) n with small sulfur-containing molecules was studied in the gas phase by Fourier transform ion cyclotron resonance mass spectrometry. With hydrated electrons and hydrated carbon dioxide radical anions, two reactions with relevance for biological radiation damage were observed, cleavage of the disulfide bond of CH 3SSCH 3 and activation of the thiol group of CH 3SH. No reactions were observed with CH 3SCH 3. The hydrated superoxide radical anion, usually viewed as major source of oxidative stress, did not react with any of the compounds. Nanocalorimetry and quantum chemical calculations give a consistent picture of the reaction mechanism. The results indicate that the conversion of e - and CO 2 •- to O 2 •- deactivates highly reactive species and may actually reduce oxidative stress. For reactions of (H 2O) n •- with CH 3SH as well as CO 2 •-(H 2O) n with CH 3SSCH 3, the reaction products in the gas phase are different from those reported in the literature from pulse radiolysis studies. This observation is rationalized with the reduced cage effect in reactions of gas-phase clusters.
UR - http://www.scopus.com/inward/record.url?scp=84860196684&partnerID=8YFLogxK
U2 - 10.1021/jp302076f
DO - 10.1021/jp302076f
M3 - Article
C2 - 22435875
AN - SCOPUS:84860196684
SN - 1089-5639
VL - 116
SP - 3824
EP - 3835
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
IS - 15
ER -