Well-defined vanadium complexes as the catalysts for olefin polymerization

2011 ◽  
Vol 255 (19-20) ◽  
pp. 2303-2314 ◽  
Author(s):  
Ji-Qian Wu ◽  
Yue-Sheng Li
Keyword(s):  
Olefin Polymerization ◽  
Vanadium Complexes

Synthesis and catalytic properties for olefin polymerization of new vanadium complexes containing silsesquioxane ligands with different denticity

2017 ◽  
Vol 66 (6) ◽  
pp. 960-967 ◽  
Author(s):  
Marzena Białek ◽  
Monika Pochwała ◽  
Adrian Franczyk ◽  
Krystyna Czaja ◽  
Bogdan Marciniec
Keyword(s):  
Olefin Polymerization ◽  
Catalytic Properties ◽  
Vanadium Complexes

[ONNO]-type amine bis(phenolate)-based vanadium catalysts for ethylene homo- and copolymerization

2009 ◽  
Vol 81 (7) ◽  
pp. 1205-1215 ◽  
Author(s):  
Christian Lorber
Keyword(s):  
Solid State ◽  
Structural Characterization ◽  
Olefin Polymerization ◽  
Oxidation States ◽  
Vanadium Complexes ◽  
Good Activity ◽  
Polymerization Catalysts ◽  
Vanadium Catalysts ◽  
Comonomer Content

The synthesis and solution and solid-state structural characterization of a family of amine bis(phenolate) [ONNO]-vanadium complexes is reviewed. These compounds have oxidation states ranging from vanadium(II) to vanadium(V), and were evaluated as olefin polymerization catalysts. In association with EtAlCl2 cocatalyst, we studied the homopolymerization of ethylene, propene, and 1-hexene, as well as the copolymerization of ethylene with α-olefins (1-hexene, 1-octene) and cycloolefins (norbornene, cyclopentene). Some of these catalysts were shown to produce copolymers with a good activity and comonomer content.

Electroanalytical chemistry of vanadium complexes: Electrochemical oxidation of [V(IV)O(nta)(H2O)]-

1989 ◽  
Vol 54 (1) ◽  
pp. 64-69 ◽  
Author(s):  
Roland Meier ◽  
Gerhard Werner ◽  
Matthias Otto
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Oxidation ◽  
Ph Dependence ◽  
Differential Pulse ◽  
Nitrilotriacetic Acid ◽  
Reduced Form ◽  
Vanadium Complexes ◽  
Differential Pulse Polarography ◽  
Electroanalytical Chemistry ◽  
Ph Range

Electrochemical oxidation of [V(IV)O(nta)(H2O)]- (H3nta nitrilotriacetic acid) was studied in aqueous solution by means of cyclic voltammetry, differential pulse polarography, and current sampled DC polarography on mercury as electrode material. In the pH-range under study (5.5-9.0) the corresponding V(V) complex is produced by one-electron oxidation of the parent V(IV) species. The oxidation product is stable within the time scale of cyclic voltammetry. The evaluation of the pH-dependence of the half-wave potentials leads to a pKa value for [V(IV)O(nta)(H2O)]- which is in a good agreement with previous determinations. The measured value for E1/2 is very close to the formal potential E0 calculated via the Nernst equation on the basis of known literature values for log Kox and log Kred, the complex stability constants for the oxidized and reduced form, respectively.

Electroanalytical chemistry of vanadium complexes. Comparison of the voltammetric features of amavadine with those of the vanadium complexes with iminodiacetic acid and methyliminodiacetic acid

1989 ◽  
Vol 54 (1) ◽  
pp. 53-63 ◽  
Author(s):  
Roland Meier ◽  
Harald Frank ◽  
Reinhard Kirmse ◽  
Reiner Salzer ◽  
Joachim Stach ◽  
...  
Keyword(s):  
Iminodiacetic Acid ◽  
Vanadium Complexes ◽  
Reduction Mechanism ◽  
Reversible Process ◽  
Electroanalytical Chemistry ◽  
Probable Explanation ◽  
Chemical Sense ◽  
Ece Mechanism ◽  
Methyliminodiacetic Acid

The voltammetric behaviour of amavadine (AV) was found to be considerably different from that of the complexes of VO2+ with methyliminodiacetic acid (MIDA) and iminodiacetic acid (IDA). To get an insight in the rather complicated reduction mechanism of the latter complexes the reductions of V(III) (MIDA) and V(III) (IDA) have been studied for comparison. The species V(III) (MIDA)2 and V(III) (IDA)2 are reduced to the appropriate V(II) complexes in a chemically reversible process. VO(MIDA)2 and VO(IDA)2 are reduced to the same complexes via an ECE mechanism. The investigation of the electroreduction of AV shows that this process is not reversible in the chemical sense. As a probable explanation, the conclusion was drawn that AV and the usual V(IV)O-iminocarboxylato complexes differ in their structures.

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