Standard molar enthalpies of formation and phase changes of Tetra-N-phenylbenzidine and 4,4′-Bis (N-carbazolyl)-1,1′-biphenyl

Abstract

The values of the standard molar energies of combustion of Tetra-N-phenylbenzidine and 4,4′-Bis(N-carbazolyl)-1,1′-biphenyl in solid phase were obtained experimentally using an isoperibolic semi-micro combustion calorimeter. The calorimeter was calibrated with benzoic acid NIST 39j and tested with 1,2,4-triazole. The molar enthalpies of combustion in oxygen, at T = 298.15 K and po = 0.1 MPa were (− 18,522.4 ± 12.1) and (− 18,114.4 ± 12.5) kJ mol−1, respectively. The corresponding standard molar enthalpies of formation were derived as: (354.4 ± 12.9) and (518.1 ± 13.4) kJ mol−1. The vaporization enthalpies of the compounds were obtained by thermogravimetry, and these values were used to derive the enthalpies of formation in gaseous phase.