Thermodynamic properties of some biphenyls

Abstract

Standard vaporization enthalpies of 4-nitrobiphenyl and 1, 1′- biphenyl are obtained on an isothermal heat conducting Calvet microcalorimeter with an estimated accuracy of ≤ 1 per cent for the first time. Standard formation enthalpies of some biphenyl derivatives in state of gas are determined. The calculation scheme by a method by “a double difference” of formation enthalpies of aromatic radicals and bond dissociation energies is offered. Using fundamental equations of the chemical physics, the new calculation method is offered to determine the energies of reorganization of molecules fragments into radicals. Formation enthalpies of radicals, namely biphenyl-4-yl and 3-methylfurazan-4-yl, are determined. Reorganization energies of radicals and bond chemical energies have been calculated.