Carbon-metal bonds, organic compounds with

Most organic chlorides, bromides and iodides react with certain metals to give compounds containing carbon-metal bonds. Such compounds are known as organo-metallic compounds. An... 

Wilkinson s catalyst after its discoverer, G. Wilkinson. In 1973, the Nobel Prize in chemistry was awarded jointly to Wilkinson and E. O. H. Fischer for their respective contributions to the field of organometallic chemistry. As you will see in this and later chapters, compounds with carbon-metal bonds (organometallic compounds) are extremely useful reagents, reactive intermediates, or catalysts in organic reactions. To a very large extent, the work of Fischer and Wilkinson created the current interest and developments in the field of transition-metal organic chemistry, which will be discussed in Chapter 31. 

Organometallic compound (Section 18.5) A compound with a covalent carbon—metal bond. Because the metal is less electronegative than carbon, the bond is polarized in the opposite direction to that found in most organic compounds that is, the negative end of the dipole is on the carbon and the positive end is on the metal. These often make useful carbon nucleophiles. 

Many transition metals and their compounds with organic ligands initiate the polymerization of alkenes and/or dienes. Some of them do not need any special treatment to this end while others require the presence of some organic or mineral compound or a special physical modification. In contrast to ZN catalysts, they are active without an organometal of Groups I—III. They are commonly known as metal alkyl free (MAF) catalysts. Many of their features are, of course, in common with ZN catalysts. MAF catalysts initiate stereoselectively controlled polymerization. Even less is known of their operating mechanism than that of ZN catalysts. It is assumed that propagation also occurs on the transition metal-carbon bond. 

Regarding antimony and bismuth, only a few studies exist involving organometallic compounds with metal-carbon bonds. Hence in these cases inorganic and organic compounds with metal—O—C bonds are also described. 

Diagonal relationships are similarities between a Period 2 element and one diagonally down and to the right in Period 3. Three such relationships are of interest to us here (Figure 14.2). The first occurs between Li and Mg. Both form nitrides with N2, hydroxides and carbonates that decompose easily with heat, organic compounds with a polar covalent metal-carbon bond, and salts with similar... 

---