Thermal Properties and Ionic Conductivity of Tetra-n-Butylammonium Perchlorate

The thermal parameters of the phase transitions and transport properties of tetra-n-butylammonium (TBA) perchlorate (n-C4H9)(4)NClO4 (TBAClO(4)) were investigated. TBAClO(4) has a polymorphous transition at 330 K and melts at 487 K. The structure of the high-temperature (HT) phase belongs to cubic symmetry and is similar to the HT phases of TBABF(4) and TBAI salts. The conductivity parameters of the low-temperature and HT phases of TBAClO(4) were determined from the Arrhenius plots. The thermodynamic parameters and transport properties of TBAClO(4) were compared with those of other TBA salts having isostructural HT phases. The polymorphous phase transition entropy was found to correlate with the conductivity of HT phases of TBA salts; TBAClO(4) has the lowest conductivity compared to TBABF(4) and TBAI salts.