Thermodynamics of weak interactions: Excess enthalpies of some binary bromoform mixtures

Excess enthalpies of bromoform + toluene, +o-xylene +m-xylene and +p-xylene have been determined at 308.15 K. These compounds have been examined for Barker's theory in order to understand the magnitude and nature of various interactions between the components of these mixtures. It has been concluded that the H-atom and one bromine atom of bromoform interact with the π cloud of the aromatic ring. These conclusions have been supplemented by n.m.r. studies. An approximate distance of the bromoform proton from the plane of the aromatic ring has also been calculated and examined in the light of the proposed geometry of the molecular complexes. Equilibrium constants for the complexations reaction have also been determined.