The thermodynamics of orientational disorder in a molecular solid: (CH3)3CCHO

Abstract

The heat capacity of tert-butylaldehyde, (CH3)3CCHO, has been measured as a function of temperature from 29 to 298 K, to investigate solid-state polymorphism. There are two solid–solid phase transitions in this material, Ttr = 158.5 and 183.9 K, ΔStr = 0.402 R and 3.153 R respectively. The thermodynamic parameters for the transitions are consistent with mechanisms proposed on the basis of recent nuclear magnetic resonance investigations of this material.