A5060444164- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Organometallic Complex Synthesis and Catalysis
- Carbon dioxide utilization in catalysis
- biodegradable polymer synthesis and properties
- Synthetic Organic Chemistry Methods
- Silicone and Siloxane Chemistry
- Mesoporous Materials and Catalysis
- Ionic liquids properties and applications
- Catalysis and Oxidation Reactions
- Insect-Plant Interactions and Control
- Plant Virus Research Studies
- Porphyrin and Phthalocyanine Chemistry
- Polymer crystallization and properties
- Biochemical and biochemical processes
- Supercapacitor Materials and Fabrication
- Thermodynamic properties of mixtures
- Iron oxide chemistry and applications
- Polymer Nanocomposites and Properties
- Polymer Science and PVC
- Catalysis for Biomass Conversion
- Metal-Catalyzed Oxygenation Mechanisms
- Thermal and Kinetic Analysis
- Respiratory and Cough-Related Research
- Membrane Separation and Gas Transport
Universidad Autónoma de Chile
2024
University of Zulia
2002-2021
Dirección de Investigación y Desarrollo
2021
Imperial College London
2005-2016
Loughborough University
2006-2009
Deuterio-ethylene labeling studies on two homogeneous chromium ethylene oligomerization catalysts show that chain propagation proceeds via metallacyclic intermediates; reactions performed in the presence of 1-nonene no incorporation higher olefin, strongly implicating involvement large ring metallacycles.
A series of co-oligomerization and copolymerization reactions C2H4/C2D4 (1:1) mixtures have been carried out using various transition metal catalysts based on Cr, Co, Fe in combination with MAO. The oligomeric α-olefin products analyzed by GC GC/MS, the experimental results compared theoretical mass spectra derived from mathematical models. Solid polymer samples 13C{1H} 13C DEPT-135 NMR spectroscopy. can be used as a method to differentiate between metallacyclic or Cossee-type chain growth...
Treatment of the bis(benzimidazolyl)amine chromium complex 2 with ethylene in presence MAO affords an exceptionally active oligomerization catalyst and unprecedented distribution 1-olefin products which C4n series is much more abundant than C4n+2 series. Deuterium labeling studies are consistent a metallacyclic chain growth mechanism unusual product arises from interplay two sites.
A series of bis(benzimidazole)-based cobalt(II) dichloride complexes containing a range different central donors has been synthesized and characterized. The nature the donor affects binding ligand to cobalt centre determines coordination geometry metal complexes. All have shown catalyse polymerization butadiene, in combination with MAO as co-catalyst, give cis-1,4-polybutadiene high selectivity. marked influence on activity catalysts, but does not affect polymer microstructure. addition...
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication the EditorNEXT1,3-Butadiene Polymerization by Bis(benzimidazolyl)amine Metal Complexes: Remarkable Microstructural Control and a Protocol for In-Reactor Blending of trans-1,4-, cis-1,4-, cis-1,4-co-1,2-VinylpolybutadieneRenan Cariou†, Juan Chirinos†, Vernon C. Gibson*†, Grant Jacobsen‡, Atanas K. Tomov†, Mark R. J. Elsegood§View Author Information Department Chemistry, Imperial College London, Exhibition Road, London SW7...
The catalytic oligomerization of ethylene with chromium-based complexes containing bis(benzimidazolemethyl)amine (BIMA) ligands results in alternating distributions linear α-olefins (LAOs). Extremely high activities are obtained (>100 000 g mmol–1 h–1 bar–1) N-alkyl-substituted BIMA ligands, whereas bulky groups on the central nitrogen or alternative donors result much lower activities. Variations ligand backbone, as well methylation benzimidazole units, lead to reduction activity. LAO have...
Abstract The effect of the alcohol nature in TiCl4 catalysts supported on MgCl2, modified by recrystallization technique with SiCl4, has been investigated terms activity and tacticity control. A series alcoholic solutions using 1-hexanol, t-butanol, butanol, iso-propanol, propanol ethanol, were recrystallized SiCl4 supports subsequently impregnated TiCl4. Also, as a way comparison, prepared from MgCl2 1-hexanol solvent evaporation quick cooling. characterized infrared energy dispersive...
Natural gas remains an important global source of energy. Usually, sour from the well or refinery stream contains H
The half-sandwich complex [{η5:σ-C5H4(CH2)2NEt}Ti(NEt2)2] was synthesized and characterized by means of IR-spectroscopy. This compound activated methylaluminoxane (MAO) for homogeneous ethene polymerization ethene/propene copolymerization. effect the Al/Ti molar ratio on activity, molecular masses, thermal properties polymers studied. weight distributions DSC measurements copolymers show presence two different catalytic sites.
The complexes [CpTi(NR 2 ) 3 ] were tested in ethene polymerisation and the effect of alkyl-amine groups on their activities was explored.
The half-sandwich complexes, [η1:η5-C9H6(CH2)2NEt]Ti(NEt2)2 and [η1:η5-C13H8(CH2)2NEt]Ti(NEt2)2, were synthesized characterized by spectroscopy techniques. These compounds activated methylaluminoxane (MAO) for homogeneous ethene polymerization. effect of the ligand Al/Ti molar ratio on polymerization activity, molecular masses thermal properties polymers studied compared with previous data obtained case analogous cyclopentadienyl (Cp) complexes. activity weight decreases in following order:...