Chapter 11, Problem 10PP

Interpretation Introduction

Interpretation:

The experiment using an isotopically labeled alcohol that would prove that the formation of an alkyl sulfonate does not cause cleavage at the C–O bond of the alcohol is to be suggested.

Concept introduction:

Electrophiles are electron deficient species that have positive or partially positive charge. Lewis acids are electrophiles that accept electron pair.

Nucleophiles are electron rich species that have negative or partially negative charge. Lewis bases are nucleophiles that 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.

Kinetic isotope study is a method of ascertaining the mechanism of reactions. There are two types of kinetic isotope studies—primary kinetic isotope studies and secondary kinetic isotope studies.

Primary kinetic isotope study evaluates the change in rate of the reaction when an atom in a bond is isotopically substituted, gets cleaved as compared to a bond containing regular isotope that gets cleaved during the course of the reaction (rate limiting as well as subsequent product determining steps). The bond substituted with the heavier isotope vibrates slower and hence, is more stable. The more stable bond requires more energy to cleave and thus slows the rates of reaction. If the rate does not change on primary kinetic isotope study, then that particular bond remains intact during the course of reaction.

The rates of reaction (or the value of rate constant) do not change on replacing regular ¹²C–O bond of the alcohol with ¹³C–O, then this would prove that the bond stays unbroken during the formation of alkyl sulfonate from alcohol.