Oxidation organometallic chemistry

Chadwick A. Tolman received his Ph.D. in physical chemistry from the University of California at Berkeley and until recently was a program officer in organic and macromolecular chemistry in the Division of Chemistry of the National Science Foundation. He is now a staff officer at the National Research Council Board on Environmental Studies and Toxicology. He has extensive experience and expertise in chemistry and chemical process development. Dr. Tolman spent 31 years in Central Research at the DuPont Experimental Station. His work has spanned a broad range of subjects, including hydrocarbon oxidation, organometallic chemistry, and the destruction of toxic organic compounds in wastewater. 

Indeed, it is the cyclopentadienyls which provide the major part of the organometallic chemistry of this group and they are known for metal oxidation states of IV, III and II though III... 

Interest in the aqueous medium spread quickly and many, sometimes surprising, discoveries were made [3]. Today pericyclic [4], condensation [5], oxidation [6] and reduction [7] reactions are routinely carried out in aqueous medium. The recent discovery of water-tolerant Lewis acids such as lanthanide triflates, Bi(OTf)j, Sc(OTf)j and Y(OTf)j has revolutionized organometallic chemistry [5a, 7]. 

Low oxidation states - An important characteristic of transition metal chemistry is the formation of compounds with low (often zero or negative) oxidation states. This has little parallel outside the transition elements. Such complexes are frequently associated with ligands like carbon monoxide or alkenes. Compounds analogous to Fe(CO)s, [Ni(cod)2] (cod = 1,4-cyclooctadiene) or [Pt(PPh3]3] are very rarely encountered outside the transition-metal block. The study of the low oxidation compounds is included within organometallic chemistry. We comment about the nature of the bonding in such compounds in Chapter 6. 

Various phosphines are valuable ligands for metal centers involved in catalytic and noncatalytic organometallic chemistry. Unfortunately, phosphines are readily oxidized to phosphine oxides and to prevent their oxidation they... 

Eerrocene (1) was the first sandwich complex to be discovered, thereby opening a wide and competitive field of organometallic chemistry. The formation of ferrocene was found at almost the same time in two independent studies on July 11, 1951, Miller, Tebboth, and Tremaine reported that on the passage of N2 and cyclopenta-diene over a freshly prepared mixture of reduced Ee (90%), alumina (8%), potassium oxide (1%), and molybdenum oxide (1%) at 300°C, yellow crystals identified as Cp2Ee (Eig. 1) were obtained [1]. Due to the low yields obtained (3 g starting from 650 g ferric nitrate), doubts remain as to whether Ee(0) was the... 

Metal particles Oxide supports Surface organometallic chemistry... 

In this review, we will specifically discuss the similarities and the differences between the chemistry on surfaces and molecular chemistry. In Sect. 2, we will first describe how to generate well-dispersed monoatomic transition metal systems on oxide supports and understand their reactivity. Then, the chemistry of metal surfaces, their modification and the impact on their reactivity will be discussed in Sect. 3. Finally, in Sect. 4, molecular chemistry and surface organometallic chemistry will be compared. 

It is first necessary to distinguish the surface organometallic chemistry on metals and on oxides since one deals with a large ensemble of metals, while the others generate dispersed metal atoms attached covalently onto the support. 

Gold carbene complexes preparation, oxidation, and ligand displacement. Journal of Organometallic Chemistry,... 

Uson, R., Laguna, A., Vicente, J. and Garcia, J. (1976) Preparation of organogold(III) complexes by oxidizing dichloro-, or bis(pentafluorophenyl)-p-bis (diphenylphosphino)ethanedigold(l). Journal of Organometallic Chemistry, 104(3), 401 06. 

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