Modification of Methylaluminoxane-Activatedansa-Zirconocene Catalysts with Triisobutylaluminum—Transformations of Reactive Cations Studied by NMR Spectroscopy
نویسندگان
چکیده
منابع مشابه
Modification of methylaluminoxane-activated ansa-zirconocene catalysts with triisobutylaluminum-transformations of reactive cations studied by NMR spectroscopy.
When triisobutylaluminum (AliBu(3)) is added to solutions containing methylaluminoxane (MAO) and rac-[Me(2)Si(ind)(2)ZrCl(2)] (ind: indenyl) in C(6)D(6), NMR spectra show that methyl-bridged mixed-alkylaluminum dimers Al(mu-Me)(2)Me(4-x)iBu(x) predominate. These dimers react with MAO under partial transfer of isobutyl groups and induce a conversion of the initially prevailing cationic trimethyl...
متن کاملMillisecond protein folding studied by NMR spectroscopy.
Proteins are involved in virtually every biological process and in order to function, it is necessary for these polypeptide chains to fold into the unique, native conformation. This folding process can take place rapidly. NMR line shape analyses and transverse relaxation measurements allow protein folding studies on a microsecond-to-millisecond time scale. Together with an overview of current a...
متن کاملProtein complexes studied by NMR spectroscopy.
Recent advances in NMR methods now allow protein complexes to be studied in great detail in a wide range of solution conditions. Isotope-enrichment strategies, resonance-assignment approaches and structural-determination methods have evolved to the point where almost any type of complex involving proteins of reasonable size may be studied in a straightforward way. A variety of isotope editing a...
متن کاملCationic alkylaluminum-complexed zirconocene hydrides: NMR-spectroscopic identification, crystallographic structure determination, and interconversion with other zirconocene cations.
The ansa-zirconocene complex rac-Me(2)Si(1-indenyl)(2)ZrCl(2) ((SBI)ZrCl(2)) reacts with diisobutylaluminum hydride and trityl tetrakis(perfluorophenyl)borate in hydrocarbon solutions to give the cation [(SBI)Zr(μ-H)(3)(Al(i)Bu(2))(2)](+), the identity of which is derived from NMR data and supported by a crystallographic structure determination. Analogous reactions proceed with many other zirco...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Chemistry - A European Journal
سال: 2007
ISSN: 0947-6539,1521-3765
DOI: 10.1002/chem.200601801