Reactions Involving Oxidative Addition of Organic Halides

Many transition metal complexes in low oxidation states react with organic halides to give oxidative addition products. These products have coordination numbers increased by 2 and the oxidation states are also higher by 2 as compared to starting compounds. Complexes possessing and electron configurations of the central metal atom most commonly undergo these oxidative addition reactions. 

2[Ni(PPh3)4] + 2a-C5H5NBr— [Ni2Br3(a-C5H4N)2(PPh3)2] + 6PPh3 (4.52) 

Many alkyl complexes of Ir(III) and Rh(III) have been obtained by addition of alkyl halides to square-planar coordination compounds of Ir(I) and Rh(I). The addition of RX to [IrCl(CO)(PPh3)2] gives cis products, while in the case of complexes of the 

The Wilkinson complex [RhC PPhj),] reacts with methyl iodide differently than with many other 16c complexes. In addition to the five-coordinate compound [Rh(Me) l2(PPh3)2], a derivative possessing coordinated Mel molecule is formed. 

In the case of some strong reducing reagents, oxidative addition reactions involve an increase by one unit of the oxidation state of the metal. 

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