کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5418971 | 1506986 | 2006 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
The reaction of electrophiles with models of iron-iron hydrogenase: A switch in regioselectivity
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Simple dithiolate-bridged dinuclear iron clusters of the form (μ-S(CH2)xS)[Fe(CO)2(PR3)]2 act as models of the active site of the enzyme iron-iron hydrogenase ([FeFe]H2ase). These complexes have been shown react with the electrophilic species, H+ and Et+(Et+=CH3CH2+) with differing regioselectivity; H+ reacts to form a 3c-2eâ Fe-H-Fe bond, while Et+ reacts to form a new C-S bond. We have used density functional theory (DFT) calculations to examine the reaction of these two electrophilic species using the computational model (μ-SCH2CH2S)[Fe(CO)2(PH3)]2. In agreement with the experimental results, protonation of the Fe-Fe bond density is found to yield a much more stable complex than protonation of a bridging sulfur atom, while alkylation of a sulfur atom of the bridging thiolate is found to yield a much more stable complex than alkylation of the iron centers. Additional computations show that a mononuclear iron(II) complex with an Fe-E bond (E=H or Et) is significantly more stable than its constitutional isomer with iron(0) and an S-E bond. The instability of a bridging ethyl complex is attributed to the inability of the ethyl group, in contrast to a hydride, to form a stable 3c-2eâ bond with the two iron centers.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Structure: THEOCHEM - Volume 771, Issues 1â3, 12 October 2006, Pages 123-128
Journal: Journal of Molecular Structure: THEOCHEM - Volume 771, Issues 1â3, 12 October 2006, Pages 123-128
نویسندگان
Jesse W. Tye, Marcetta Y. Darensbourg, Michael B. Hall,