ESR Studies on Ziegler-Natta Catalyst Systems
نویسندگان
چکیده
منابع مشابه
Quadrupolar nutation NMR to discriminate central and satellite transitions: Spectral assignments for a Ziegler-Natta catalyst.
In this contribution we used solid state 35Cl (I=3/2) quadrupolar NMR to study a MgCl2/2,2-dimethyl-1,3-dimethoxypropane (DMDOMe) adduct that serves as a model system for Ziegler-Natta catalysis. Employing large Radio-Frequency (RF) field strengths we observe three spectral features with strongly varying line widths. The assignment of the spectra is complicated because of the large difference i...
متن کاملPrecise Active Site Analysis for TiCl3/MgCl2 Ziegler-Natta Model Catalyst Based on Fractionation and Statistical Methods
In heterogeneous Ziegler-Natta catalysts for olefin polymerization, isolation of a single type of active sites is a kind of ambition, which would solve long-standing questions on the relationship between active site and polymer structures. In this paper, polypropylene produced by TiCl3/MgCl2 model catalysts with minimum Ti heterogeneity was analyzed by combined solvent fractionation and the two...
متن کاملZiegler-Natta Catalysis: Structural Variations and Tacticity Control
Models for the likely active catalysts in homogeneous Ziegler-Natta systems have been studied using ab initio quantum chemical methods. We investigated the geometries of the isoelectronic model complexes, X2M-R where X = C1 or Cp = (q5-CsHs); where M = Sc and Ti+ (and also Ti); and where R = H, CH3, or SiH3. The general trend is that the M = Sc compounds strongly prefer a planar configuration, ...
متن کاملChromium(III) Based Ziegler-Natta Catalysts for Olefin Polymerization
Four chromium based oxo-trinuclear carboxylate complexes were prepared by reacting chromium(III) nitrate nonahydrate with acetic acid and substituted carboxylic acids. They were characterized using infrared spectroscopy (FT-IR). Chromium content of the complexes was determined by titrimetry method. The chromium(III) monochloroacetate complex, [Cr3O(ClCH2COO)6.3H2O]NO3.3H2O in combination with d...
متن کاملThe coordinative state of aluminium alkyls in Ziegler-Natta catalysts.
The most commonly used cocatalyst species in Ziegler-Natta catalysts are aluminium alkyls. In this study we aim to find the interaction between aluminium centres of these activators and other components in the ZNC system. Initially we look at binary systems of Al-alkyl/MgCl2 and ternary systems of Al-alkyl/MgCl2/TiCl4, followed by donor containing systems. The aluminium alkyls prove to be very ...
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ژورنال
عنوان ژورنال: The Journal of the Society of Chemical Industry, Japan
سال: 1970
ISSN: 0023-2734,2185-0860
DOI: 10.1246/nikkashi1898.73.2_276