Mechanistic Studies of Ethylene Hydrophenylation Catalyzed by Bipyridyl Pt(II) Complexes

This article discusses mechanistic studies of ethylene hydrophenylation catalyzed by bipyridyl Pt(II) complexes

Methyl Complexes of the Transition Metals

Organometallic chemistry can be considered as a wide area of knowledge that combines concepts of classic organic chemistry, that is, based essentially on carbon, with molecular inorganic chemistry, especially with coordination compounds. Transition-metal methyl complexes probably represent the simplest and most fundamental way to view how these two major areas of chemistry combine and merge into novel species with intriguing features in terms of reactivity, structure, and bonding. Citing more than 500 bibliographic references, this review aims to offer a concise view of recent advances in the field of transition-metal complexes containing M-CH fragments. Taking into account the impressive amount of data that are continuously provided by organometallic chemists in this area, this review is mainly focused on results of the last five years. After a panoramic overview on M-CH compounds of Groups 3 to 11, which includes the most recent landmark findings in this area, two further sections are dedicated to methyl-bridged complexes and reactivity.Ministerio de Ciencia e Innovación Projects CTQ2010–15833, CTQ2013-45011 - P and Consolider - Ingenio 2010 CSD2007 - 00006Junta de Andalucía FQM - 119, Projects P09 - FQM - 5117 and FQM - 2126EU 7th Framework Program, Marie Skłodowska - Curie actions C OFUND – Agreement nº 26722

Synthesis, Characterization and Protonolysis mechanistic studies of diimine Pt diphenyl complexes of relevance to C‐H activation

Catalysis by platinum Pt and other noble metals is involved in industrial processes that convert petroleum and natural gas resources to useful fuels and other value-added chemicals. The cleavage of carbon-hydrogen bonds in hydrocarbons is of crucial importance in these processes. The C-H bonds are very strong, and the metals are needed because they assist the cleavage of these bonds. The research group of professor Tilset at the UiO Department of Chemistry has focused on how such C-H bond cleavage reactions occur, i.e. to establish the reaction mechanisms. Jerome Parmene, as a member of this group, has taken this research into new directions. Significant parts of his work have been conducted in collaboration with professor van Eldik’s group at Erlangen University, Germany. The two groups have combined their expertise to undertake mechanistic and kinetic studies with the use of state-of-the-art NMR and UV-visible-light spectroscopy. Parmene has synthesized and characterized a range of new Pt complexes in the Oslo laboratories. The reactions of these Pt diphenyl complexes with strong acids have been studied by the using the complementary techniques available in Oslo and Erlangen. The combined efforts have provided a much improved mechanistic understanding. It has been clearly shown how electronic and steric effects of the ligands that are bonded to the metal affect the way that these reactions proceed. It is concluded that protonation of neutral diimine Pt diphenyl complexes takes place at the metal, rather than at the phenyl groups. This issue was highly debated prior to this work. When acetonitrile, a strongly coordinating ligand, is present, unstable cationic hexacoordinate Pt hydride complexes are formed. In the absence of acetonitrile, unstable Pt phenyl π-benzene complexes are obtained. Both types of complexes liberate benzene when heated. The two benzene-producing reactions have been thoroughly studied and proceed by quite different mechanisms. The findings may assist the development of new and improved catalysts that will have practical applications