Chapter FRP, Problem 5P

Interpretation Introduction

Interpretation:

The free energy diagram for each of the given reactions is to be drawn. The axes, transition state(s), energy of activation for each step and enthalpy change ($△H$) are to be labeled. The structures of the reactants, products, and intermediates are to be shown.

Concept Introduction:

Free energy diagrams are the graphical representations for a reaction in which free energy change in a reaction is monitored with the progress of the reaction. These diagrams are helpful in conveying thermodynamic and kinetic studies of the reaction.

Electrophiles are electron deficient species which has positive or partially positive charge. Lewis acids are electrophiles which accept electron pair.

Nucleophiles are electron rich species which has negative or partially negative charge. Lewis bases are nucleophiles which donate electron pair.

Free radical is an atom, molecule or ion that has unpaired electrons which makes it highly chemically reactive.

Substitution reaction: A reaction in which one of the hydrogen atoms of a hydrocarbon or a functional group is substituted by any other functional group is called substitution reaction.

Elimination reaction: A reaction in which two substituent groups are detached and a double bond is formed is called elimination reaction.

Addition reaction: It is the reaction in which unsaturated bonds are converted to saturated molecules by the addition of molecules.

Carbocation is a molecule having a carbon atom bearing three bonds and a positive formal charge.

Carbocation are generally unstable because they do not have eight electrons to satisfy the octet rule.

The order of stability of carbocation is such that the tertiary carbocation is the most stable whereas the primary carbocation is the least stable, and secondary carbocation lies between primary and tertiary carbocations.

If primary carbocation is obtained in product, it rearranges itself to secondary or tertiary carbocation to form more stable product.

If secondary carbocation is obtained in product, it rearranges itself to tertiary carbocation to form more stable product.

The stability of carbocation:

${\text{3}}^{\text{o}}\text{carbocation}\text{>}{\text{2}}^{\text{o}}\text{carbocation}{\text{>1}}^{\text{o}}\text{carbocation}\text{>methyl}\text{carbocation}$