Spectra and structure of binary azeotropes V-acetone–cyclopentane

Acetone and cyclopentane make a minimum boiling homogeneous binary azeotrope with mole ratio 2:3. Some characteristic vibrational modes, as well as 1H NMR signals change due to the azeotrope formation. The extend of interaction of these molecules causes significant changes on some vibrational modes involved and 1H NMR signals show some changes on their position. In this work the FTIR and 1H NMR spectra of pure acetone, pure cyclopentane and corresponding azeotrope were recorded, mutual influences resulting from azeotrope formation have been analyzed, and spectral changes has been discussed. The unit-structure of cluster have been deduced, based on mole ratio, boiling point depression of constituents, and comparison between the spectra obtained by FTIR and 1H NMR techniques.