Conformational Analysis of IR Spectra of Alkyl and Fluoroalkyl Cyclohexanecarboxylic Acids

IR spectra were simulated for a series of alkyl and fluoroalkyl cyclohexanecarboxylic acids, whose experimental spectra have been previously recorded in the temperature range 77–500 K. The simulation was performed taking into account the conformational mobility of the molecules and a decrease in the hydrogenbond energy of Hcomplexes during heating. It has been shown that temperatureinduced changes in the spectra are caused by conformational transitions accompanied by rotation of alkyl/fluoroalkyl and or carboxyl groups and a decrease in hydrogebond energy during heating.