Vibrational spectra and phase transitions in 1,1′-diadamantyl ketone

Abstract

IR and Raman spectra of 1,1′-diadamantyl ketone have been studied as well as the calorimetric behaviour (DSC) of the sample. Enthalpy and entropy values for the observed phase transitions are reported. From the analysis of thermodynamic data and vibrational spectra registered at different temperatures the transition prior to melting has been identified as taking place between two ordered solids. Continuous changes observed in some vibrational bands with temperature have been assigned to rotation of the adamantyl groups around their three-fold axis which originate different molecular conformations. On the other hand vibrational data indicate a molecular structure with no symmetry for this compound in agreement with the theoretically predicted geometry.