Other Through-Bond Coupling Units

Schematically shown in 11.42 and 11.43 are two p orbitals coupled via the a bond framework of four and five single bonds, respectively. The 1,2-interactions  

11 ORBITAL INTERACTIONS THROUGH SPACE AND THROUGH BONDS 

The ionization potentials for the ai and 62 7r-bond combinations as a function of the angle between the TT-bonds, co. The dashed line refers to the overlap between the 7t orbitals as a function of co. 

---

B. Other Through-Bond Coupling Units, 198 11.4. Breaking a C-C Bond, 200... 

On the other hand, in the case of a chain reaction, an induced active bond continues to react until it loses its activity through the active bond coupling reaction 4 ). In this case, Charlesby showed that an active bond makes j/(l-j) crosslinking units, where j is termed the chain reaction activity ( i=l-j, where i is termed the inhibition activity by Charlesby ) and it depends on the individual monomer concentration 5 ). Thus, the relationship is expressed as... 

The middle Cp ligand effectively couples the electrons between the two CpM units. In other words, there is a strong through-bond rather than through-space interaction. The 18-electron rule obviously cannot be used for these situations. An MO-based, delocalized description like that presented in Figure 20.5 must be utilized. 

---