کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1325975 977412 2010 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Chelate ring closing and opening behavior in cyclopentadienyl cobalt(III) complexes with pendant nitrogen functional group
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی معدنی
پیش نمایش صفحه اول مقاله
Chelate ring closing and opening behavior in cyclopentadienyl cobalt(III) complexes with pendant nitrogen functional group
چکیده انگلیسی

Kinetic studies were performed for the chelate ring closing and opening process of cyclopentadienyl cobalt(III) complexes having a pendant N-functional group with an amine, piperidine or pyridine moiety in the side chain. The metal–nitrogen bond energy was measured. The rate of chelation by such pendant N-functionalized side chains in diiodomonocarbonyl cobalt(III) reaction intermediates is determined by the electronic density on the donor atom and the strength of the forming chelated bond. The steric factor around the donor atom plays a secondary role. On the basis of the enthalpies and entropies obtained from the kinetic studies, the process of chelate ring closing in diiodomonocarbonyl cobalt(III) reaction intermediates is via an associative pathway involving loss of CO, while the chelate ring opening process in the resulted chelators is via a metal–nitrogen bond cleavage, solvation then metal–phosphorus bond formation pathway during substitution of PPh3. The chelator with the most rigid arm of picolyl shows a smallest steric hindrance for incoming PPh3 compared to the other two analogues.

Chelate ring closing and opening process of diiodomonocarbonyl cyclopentadienyl cobalt(III) complexes bearing pendant N-functional group is studied. The rate of chelation is determined by electronic density on the donor atom and the strength of forming chelated bond via associative pathway while chelate ring opening is via dissociative pathway.Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Organometallic Chemistry - Volume 695, Issue 4, 15 February 2010, Pages 588–594
نویسندگان
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