Branching Out: How Constitutional Isomerism Influences Volatility in Butyl Acetates

Abstract

This project investigates how molecular branching affects the evaporation rate (volatility) of butyl acetate isomers used in fragrances. By analysing published chemical data, I compared linear and branched structures. The results proved that increased branching lowers boiling points (from 125.95°C to 97.43°C) and raises vapour pressure (from 12.15 to 47.08 mmHg). Compact, branched shapes reduce molecular surface area, weakening the London dispersion forces holding the liquid together. Connectivity alone explained 52.9% of boiling point variance, demonstrating that changing a molecule’s shape strongly influences how fast a fragrance releases its scent.