English  |  正體中文  |  简体中文  |  全文筆數/總筆數 : 51281/86342 (59%)
造訪人次 : 8151335      線上人數 : 88
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library & TKU Library IR team.
搜尋範圍 查詢小技巧:
  • 您可在西文檢索詞彙前後加上"雙引號",以獲取較精準的檢索結果
  • 若欲以作者姓名搜尋,建議至進階搜尋限定作者欄位,可獲得較完整資料
  • 進階搜尋
    請使用永久網址來引用或連結此文件: http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/98605

    題名: Hammett correlations as test of mechanism of CO-induced disulfide elimination from dinitrosyl iron complexes
    作者: Randara Pulukkody;Samuel J. Kyran;Michael J. Drummond;Hsieh, Chung-Hung;Donald J. Darensbourg;Marcetta Y. Darensbourg
    貢獻者: 淡江大學化學學系
    日期: 2014-10
    上傳時間: 2014-08-27 09:20:30 (UTC+8)
    出版者: Cambridge: R S C Publications
    摘要: The displacement of RS˙ from [(NHC)(SPh)Fe(NO)2] (NHC = N-heterocyclic carbene) by carbon monoxide follows associative kinetics, rate = k [CO]1 [(NHC)(SPh)Fe(NO)2]1, resulting in reduction of the oxidized form of the dinitrosyliron unit, {Fe(NO)2}9 (Enemark–Feltham notation) to {Fe(NO)2}10. Thermodynamically driven by the release of PhS–SPh concomitant with formation of [(NHC)(CO)Fe(NO)2], computational studies suggested the reactant dinitrosyliron unit serves as a nucleophile in the initial slanted interaction of the π* orbital of CO, shifting into normal linear Fe–CO with weakening of the Fe–SPh bond. The current study seeks to experimentally test this proposal. A series of analogous {Fe(NO)2}9 [(NHC)(p-S–C6H4X)Fe(NO)2] complexes, with systematic variation of the para-substituents X from electron donor to electron withdrawing groups was used to monitor variation in electron density at the Fe(NO)2 unit via Hammett analyses. Despite the presence of non-innocent NO ligands, data from ν(NO) IR spectroscopy and cyclic voltammetry showed consistent tracking of the electron density at the {Fe(NO)2} unit in response to the aryl substituent. The electronic modifications resulted in systematic changes in reaction rates when each derivative was exposed to CO. A plot of the rate constants and the Hammett parameter σp is linear with a negative slope and a ρ value of −0.831; such correlation is indicative of rate retardation by electron-withdrawing substituents, and provides experimental support for the unique role of the delocalized frontier molecular orbitals of the Fe(NO)2 unit.
    關聯: Chemical Science 5(10), pp.3795-3802
    DOI: 10.1039/C4SC01523A
    顯示於類別:[化學學系暨研究所] 期刊論文


    檔案 描述 大小格式瀏覽次數
    2041-6520_5(10)p3795-3802.pdf1244KbAdobe PDF195檢視/開啟



    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library & TKU Library IR teams. Copyright ©   - 回饋