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Title: Electronic structure and fragmentation properties of [Fe 4S 4(SEt) 4-x(SSEt) x] 2-

Abstract

A limited exposure of (n-Bu 4N) 2[Fe 4S 4(SEt) 4] solutions in acetonitrile to air was found to produce a new series of [4Fe–4S] cluster complexes, [Fe 4S 4(SEt) 4-x(SSEt) x] 2- (x = 1–4), with the original –SEt ligands substituted by –SSEt di-sulfide ligands, which were formed due to partial decomposition of the [4Fe–4S] core in parent [Fe 4S 4(SEt) 4] 2-. The products were first observed in the experiments with an ESI-ion Trap-TOF mass spectrometer and were further identified using high resolution Fourier transform ion cyclotron resonance (FTICR) mass spectrometer. Photoelectron spectra of the [Fe 4S 4(SEt) 4-x(SSEt) x] 2-dianions revealed that the –SSEt coordination induced little change in the electronic structure of the [4Fe–4S] cluster, but the electron binding energies of [Fe 4S 4(SEt) 4-x(SSEt) x] 2- increased from 0.52 to 0.73 eV with increase in x from 0 to 4, suggesting a greater electron withdrawing ability of –SSEt than –SEt. In high resolution MS/MS experiments on [Fe 4S 4(SEt) 3(SSEt)] 2-/1-, clusters with both charge states yielded fragment [Fe 4S 4(SEt) 3] -, suggesting that –SSEt could be lost either as a negatively charged ion SSEt- from the doubly charged precursor, or as a radical SSEtmore » from the singly charged species. Furthermore, the biological implication of the interaction between [Fe 4S 4(SEt) 4] 2- and O 2 is discussed in comparison to the air exposure of [4Fe–4S] proteins to the air.« less

Authors:
 [1];  [1];  [1]
  1. Washington State Univ., Richland, WA (United States). Dept. of Physics; Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Publication Date:
Research Org.:
Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org.:
USDOE Office of Science (SC), Biological and Environmental Research (BER)
OSTI Identifier:
1152302
Resource Type:
Journal Article
Resource Relation:
Journal Name: International Journal of Mass Spectrometry; Journal Volume: 263; Journal Issue: 2-3
Country of Publication:
United States
Language:
English
Subject:
FTMS; Electrospray ionization source; Tandem mass spectrometry; Photoelectron spectroctroscopy; Fe–S protein

Citation Formats

Fu, You-Jun, Laskin, Julia, and Wang, Lai-Sheng. Electronic structure and fragmentation properties of [Fe4S4(SEt)4-x(SSEt)x]2-. United States: N. p., 2007. Web. doi:10.1016/j.ijms.2007.03.001.
Fu, You-Jun, Laskin, Julia, & Wang, Lai-Sheng. Electronic structure and fragmentation properties of [Fe4S4(SEt)4-x(SSEt)x]2-. United States. doi:10.1016/j.ijms.2007.03.001.
Fu, You-Jun, Laskin, Julia, and Wang, Lai-Sheng. Fri . "Electronic structure and fragmentation properties of [Fe4S4(SEt)4-x(SSEt)x]2-". United States. doi:10.1016/j.ijms.2007.03.001.
@article{osti_1152302,
title = {Electronic structure and fragmentation properties of [Fe4S4(SEt)4-x(SSEt)x]2-},
author = {Fu, You-Jun and Laskin, Julia and Wang, Lai-Sheng},
abstractNote = {A limited exposure of (n-Bu4N)2[Fe4S4(SEt)4] solutions in acetonitrile to air was found to produce a new series of [4Fe–4S] cluster complexes, [Fe4S4(SEt)4-x(SSEt)x]2- (x = 1–4), with the original –SEt ligands substituted by –SSEt di-sulfide ligands, which were formed due to partial decomposition of the [4Fe–4S] core in parent [Fe4S4(SEt)4]2-. The products were first observed in the experiments with an ESI-ion Trap-TOF mass spectrometer and were further identified using high resolution Fourier transform ion cyclotron resonance (FTICR) mass spectrometer. Photoelectron spectra of the [Fe4S4(SEt)4-x(SSEt)x]2-dianions revealed that the –SSEt coordination induced little change in the electronic structure of the [4Fe–4S] cluster, but the electron binding energies of [Fe4S4(SEt)4-x(SSEt)x]2- increased from 0.52 to 0.73 eV with increase in x from 0 to 4, suggesting a greater electron withdrawing ability of –SSEt than –SEt. In high resolution MS/MS experiments on [Fe4S4(SEt)3(SSEt)]2-/1-, clusters with both charge states yielded fragment [Fe4S4(SEt)3]-, suggesting that –SSEt could be lost either as a negatively charged ion SSEt- from the doubly charged precursor, or as a radical SSEt from the singly charged species. Furthermore, the biological implication of the interaction between [Fe4S4(SEt)4]2- and O2 is discussed in comparison to the air exposure of [4Fe–4S] proteins to the air.},
doi = {10.1016/j.ijms.2007.03.001},
journal = {International Journal of Mass Spectrometry},
number = 2-3,
volume = 263,
place = {United States},
year = {Fri Jun 01 00:00:00 EDT 2007},
month = {Fri Jun 01 00:00:00 EDT 2007}
}