Covalent Bond Classification Method

The Covalent Bond Classification (CBC) Method is an insightful approach specifically designed for covalent molecules and is particularly applicable to organometallic compounds. The conceptual core of the CBC method is to classify each ligand as a neutral species on the basis of its orbital interactions with the metal. This classification requires considering three fundamental interactions, represented by the symbols L, X, and Z 

TABLE 13.8 Fundamental Metal-Ligand Interactions In the CBC Method 

Ligand Function Orbital Requirement Designations and Simple Examples 

X Ligand features an orbital that donates one electron to the metal Cl, Br, I, H, R (alkyl) 

FIGURE 13.52 Covalent Bond Classification of Iron Complexes. 

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CBC method, see Covalent bond classification method -bridged complexes... 

Covalent bond classification method, organotransition metal compounds ([Pg.87]

Figure 1 Classification and examples of L, X, and Z ligands according to the Covalent Bond Classification method...

Covalent Bond Classification Method 523 TABLE 13.9 Information Available from the Equivalent Neutral Class Formula... 

Use the Covalent Bond Classification Method to classify these complexes with a [ML/X ZJ formula. With charged species, reduce the formula to its equivalent neutral class. 

Use the Covalent Bond Classification Method to classify these hypothesized complexes with a [ML/X ] formula. With charged species, reduce the formula to its equivalent neutral class. On the basis on the MLX plot for iron in Section 13.7, speculate on the likelihood that the following iron complexes have been prepared. 

The Covalent Bond Classification Method and MLX plots are now introduced in Chapter 13. 

M. L. H. Green, J. Organomet. Chem. 500 (1983), 127. The Green method is also called the Covalent-Bond-Classification (CBC) method. 

There are several means to modify polymer properties, grafting is one of the effective methods. Grafting is a method in which monomers are covalently bonded (modified) onto the polymer backbone [16], as shown in Figure 3.2. Graft copolymers are special type of polymers that come under the classification of branched... 

The physical and chemical properties of the inorganic azides have been extensively reviewed [4-11], Richter [12] has discussed the chemical classification of azides as (i) stable ionic azides, (ii) heavy-metal azides and (iii) unstable covalent azides. This classification is based on the percentage ionic character of the metal-azide bond, tabulated as formal ionicities in [12]. For example, the Na-Nj and Ba-Nj bonds are 70% ionic, but Pb-N, is only 34% and H-Nj is 22%. Bertrand et al. [13] have reviewed the photochemical and thermal behaviour of organometallic azides. Richter has also given [12] an excellent review of the methods of preparation of HNj and other azides. He criticizes early workers for inadequate purification and characterization of their starting materials and their neglect of allowance for the possible formation of hydrates (e.g., barium azide may be present as Ba(N3)2.1. SHjO below 284 K, forms a monohydrate between 284 and 325.5 K and is anhydrous above 325.5 K). 

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