Appendix —Four Electrons Three Orbitals VB Treatment

APPENDIX B-THE FOUR ELECTRONS/THREE ORBITALS VB TREATMENT 

Many reactions can be described qualitatively by considering only three orbitals with four electrons. This includes proton transfer reactions (A - H + B-— A + H - B) and 8 2 reactions (X- Z + Y - X + Z- Y). The VB description of these reactions requires in principle the six states depicted in Fig. 2.7, which considered the typical case of the X + CH3-Y— X-CH3 + Y Sn2 reaction. 

However, a qualitative consideration of the relevant energetics (Table 

TABLE 2.4. Back of the Envelope Estimation of the Energies of Valence-Bond States of the X- + CH3X- XCH3 +X- SN2 reaction  

CHEMICAL REACTIONS IN THE GAS PHASE AND IN SIMPLE SOLVENT MODELS 

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