Unimolecular Nucleophilic Substitution (S N 1): Structural Reactivity Evidenced by Colored Acid–Base Indicators

CASTRO-GODOY, WILLBER D.; ARGÜELLO, JUAN E.; MARTINELLI, MARISA; CAMINOS, DANIEL A.

JOURNAL OF CHEMICAL EDUCATION

AMER CHEMICAL SOC

Año: 2018

0021-9584

he different reactivities between 1º, 2º and 3º butyl chlorides by the unimolecular nucleophilic substitution (SN1) mechanism was easily observed at 60 °C by a solvolysis reaction in ethanol with ether formation. The hydrogen ion from the by-product HCl reacted with an acid-base indicator such as methyl red to induce a color change. At room temperature, the addition of AgNO3 was used to detect the released chloride ion by AgCl precipitation. The reactivity order (3º > 2º >>>1º) was visually confirmed by both a color change in an indicator and precipitate formation by these safe, quick, and easy assays