Bonding of Oxo and Imido Complexes

A valence bond description of metal-imido and metal-oxo complexes. 

Two linear imido complexes possessing 17-electron counts in the absence of a ligand-to-metal dative IT-bond. 

A trisimido complex possessing partial ligand-to-metal ir-bonding due to symmetry considerations. Adapted with permission from Sohrock, R. R. J.Am. Chem.Soc. 1990, 112,1642. 

Synthesis of MetaMmido and Metal-Oxo Complexes 13.4.4.1. Synthe s of MetaNmido Complexes 

Many routes to 0x0 and imido compounds have been developed. Transition metal-oxo complexes are coimnonplace and, in many cases, are the most stable form of an element in air. Some imido compoimds, including the first imido complex, have been prepared from metal-oxo complexes (Equation 13.50). The reactions of some of the later metal-oxo compounds with a primary amine generate an imido species by extrusion of water. In other cases, metal-imido complexes are prepared from 0x0 complexes by the reaction of phosphmimines (Equation 13.51) or from 0x0 or halo complexes by the reactions of silylamines (Equations 13.52 and 13.53). The driving force for these reactions is the formation of phosphine oxide, silyl ethers, or silyl halides. 

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