Some thermochemical studies on binary faceted organic eutecitcs and 1∶1 molecular complexes

Abstract

The phase diagrams of binary organic systems of benzidine with pyrogallol and p-nitrophenol give a double simple euteetic type phase diagram showing formation of a I: 1 molecular complex with congruent melting point and two eutectics. The growth data on the pure components, the euteetics and the molecular complexes, determined by measuring the rate of movement of growth front in a capillary, justify the square relationship between growth velocity and undereooling. While enthalpy of mixing values suggest intermoleeular hydrogen bonding, the excess thermodynamic functions reveal strong interactions among the components forming euteeties and addition compounds.

Phase diagram and thermochemical properties of organic eutectic in a monotectic system

“…The values of enthalpy of fusion of the pure components, the eutectic and the monotectic, determined by the DSC method are given in table 1. For the purpose of comparison the enthalpy of fusion of the eutectic, calculated by the mixture law (Rai and George 1996), is also given in the same table.…”

Some Physicochemical Studies on Organic Analog of Metal‐Nonmetal Eutectics

“…The excess thermodynamic functions (RAI, GEORGE, 1996) which give quantitative measure of deviation the system from ideal behaviour are defined as the difference between the thermodynamic function of mixing for a real system and the corresponding value for an ideal system at the same temeprature and pressure. The values of excess free energy (8), excess enthalpy (hE) and excess entropy ( p ) are calculated using the (Table 4) suggest (RAI, GEORGE, 1996) that the interaction between like molecules is stronger than that between the unlike molecules.…”

“…The values of excess free energy (8), excess enthalpy (hE) and excess entropy ( p ) are calculated using the (Table 4) suggest (RAI, GEORGE, 1996) that the interaction between like molecules is stronger than that between the unlike molecules. The values of hE and # correspond to the excess free energy and are measure of excess enthalpy and excess entropy of mixing, respectively.…”