Alkene Complexes General Information Alkene or olefin ligands are common in organotransition metal chemistry. Bonding and Structure in Alkene Complexes The bonding in alkene complexes is described by the Dewar-Chatt-Duncanson model, which provides us with a bonding picture not unlike that seen in carbonyl or phosphine complexes.
Multimetallic Polymerization Catalysis Research in the Agapie laboratory is targeted toward developing new, practical catalysts by using inspiration from biological systems. Some of the most fascinating catalysts in Nature display complex inorganic cofactors, sometimes in combination with organic cofactors, and perform chemical transformations water reduction and oxidation, carbon dioxide reduction, dinitrogen reduction, dioxygen reduction that are arguably prerequisites for the advance of society in the current context of limiting energy resources and environmental concerns.
Given the scale of the potential applications, we focus on studies of inexpensive and abundant first-row transition metals. To these ends we have developed new methodologies for the synthesis of complex inorganic targets and have performed mechanistic studies to understand the properties and reactivity of these compounds.
Our research focuses on three general topics: With mixed metal oxides as catalysts for water oxidation and O2 reduction in heterogeneous and biological systems, fundamental understanding of the effects of redox inactive metals on the chemistry of Olefin metathesis ethylene metal oxide clusters is important for the rational development of effective catalysts.
Prior to our work, a single high oxidation state complex displaying an oxo bridged redox active — redox inactive heterometallic core had been structurally characterized and studied for redox chemistry, though examples of in situ modulation of reactivity by metal Lewis acids had been reported.
We have developed rational strategies for the synthesis of a series of well-defined heterometallic oxide clusters that have allowed for systematic structure-property studies. The reduction potentials of these clusters were found to depend linearly on the Lewis acidity of the redox inactive metal.
This finding has applications in rationally tuning the reduction potentials of metal oxide clusters to match the thermodynamic requirements of the desired redox transformations. Mechanistic studies have provided insights into the mechanism of cluster assembly and O- and H-atom transfer.
Synthesized complexes have been studied by collaborators for spectroscopic benchmarking relative to the biological system.
In the context of small molecule activation, the ability of protein active sites to transfer electrons and protons is instrumental for selectivity and high reaction rates.
We have developed new molecular architectures for multimetallic complexes of redox active metals and monometallic complexes of non-innocent ligands. Although non-innocent ligands have often been employed to transfer electrons or protons, pendant groups that transfer both are relatively rare, despite the biological precedent.
Moieties such as catechol and hydroquinone are envisioned to act as reservoirs of both electrons and protons, if placed in proximity of metals orthogonally to the arene plane. Toward that end, hemi-labile arene ligands with pendant donors have been employed for their versatility and potential to lower reaction barriers by accommodating several metal binding modes.
New types of bimetallic reactivity C-C coupling with Nicatalysts Mo catalyzed ammonia-borane dehydrogenationand mechanistic insights metal mediated aryl C-O bond activation, H-transfer to arene have been achieved.
The functionalized versions of these systems, with catechol and hydroquinone moieties, bind metals while retaining the protonated state. Therefore, they can deliver not only electrons, but also protons to substrates such as O2, clearly showing the potential of such motifs for metal mediated multi-electron and multi-proton chemistry.
The insertion polymerization of polar monomers has been a significant challenge in polyolefin synthesis. Bimetallic catalysts have been proposed as candidates to address this problem, but the molecular design of many of the known systems has provided limited insight into the reaction mechanism due to high flexibility or distant placement of metals.
We have prepared bimetallic complexes with rigid organic linkers that lock the metals centers at well-defined positions. Our studies have revealed a mechanism of bimetallic cooperativity that contrasts with other proposals in the literature, with reactivity being affected by the steric interaction between coordinated ligands.
Due to these interactions, the catalytic activity and the stereocontrol are increased, and deactivation by polar groups such as amines is lowered. These mechanistic insights are expected to allow for the development of catalysts with better functional group tolerance.
David Britt, and Theodor Agapie.
Lopez, and Theodor Agapie. Reed and Theodor Agapie. VanderVelde, and Theodor Agapie. Buss, Christine Cheng, and Theodor Agapie. Chalkley, and Theodor Agapie. Buss, and Theodor Agapie.
Hirscher and Theodor Agapie. Oyala, and Theodor Agapie. Yachandra, Junko Yano, and Philippe Wernet.
Aliphatic polyethers generated by the ring-opening polymerization (ROP) of the epoxide monomers ethylene oxide (EO), propylene oxide (PO), and, to a lesser extent, butylene oxide (BO) are a highly established and important class of polymers that are commercially . Olefin: Olefin, compound made up of hydrogen and carbon that contains one or more pairs of carbon atoms linked by a double bond. Olefins are examples of unsaturated hydrocarbons (compounds that contain only hydrogen and carbon and at least one double or . To manufacture polypropylene copolymer, a second monomer is required Ã¢Â€Â“ typically ethylene. The manufacture of homopolymer or random copolymer can be accomplished within a single reactor, whereas the manufacture of impact copolymer or TPOs necessitates at least two reactors in series.
Takase, and Theodor Agapie. Peters, and Theodor Agapie. Carsch, Graham de Ruiter, and Theodor Agapie. Tsui, and Theodor Agapie. Takase, Junko Yano, and Theodor Agapie. Lichterman, Theodor Agapie, Charles C. McCrory, and Jonas Peters.
Structure, Functions, and Interactions; Art E.Olefin metathesis is an equimolar olefin interconversion technology, where two olefins are reacted with each other to produce two different olefins.
Olefin cracking utilises zeolitic cracking catalyst technology to crack the olefins to a . timberdesignmag.com Free directory and search engine dedicated to the polymer industries.
Only sites related to rubber, plastics or adhesives are considered for inclusion. Petro Rabigh starts production at 10 units of its phase-two project Upon completion of all phase two plants, both phases one and two will be integrated operationally .
In view of the potential benefits of producing propylene via metathesis of ethylene and butenes, this review evaluates an SRIC design for on-purpose propylene production based on Olefins Conversion Technology (OCT) licensed by . Theodor Agapie was born in in Bucharest, Romania. He received his timberdesignmag.com degree from Massachusetts Institute of Technology in and his Ph.D.
. In organic chemistry, an alkene is an unsaturated hydrocarbon that contains at least one carbon–carbon double bond. The words alkene and olefin are often used interchangeably (see nomenclature section below).
Acyclic alkenes, with only one double bond and no other functional groups, known as mono-enes, form a homologous series of hydrocarbons with the general formula C n H 2n.