Conformational behaviour and vibrational spectra of cyclopropylcarbinol and 1-cyclopropylethanol

Infrared spectra in the vapour, liquid and crystalline states as well as in dilute CCl₄ solution, and Raman spectra in the liquid and crystalline states were recorded for cyclopropylcarbinol and 1-cyclopropylethanol. Some weak vibrational bands present in the spectra of the vapours, liquids and solutions vanished in the crystalline solids. The spectra of each compound have been interpreted in terms of an equilibrium between a stable conformer, dominating in the vapour and liquid states and exclusively present in the crystals and one or more other conformers of small abundance. Vibrational assignments are presented for the ring modes and for those modes which are sensitive to conformational changes.