A flow microcalorimeter has been used to determine excess enthalpies, HE, at 298.15 K of binary mixtures of dipentylether, dihexylether, 1,2-dimethoxyethane and 1,2-diethoxyethane (1)+benzene (2).
These data along with the data available in the literature on HE, molar excess Gibbs energies, GE and liquid-vapour equilibria (LVE) of non-cyclic monoethers, acetals, polyethers and of cyclic mono- and di-ethers+benzene
are examined on the basis of the DISQUAC group contribution model. Using a set of adjusted interchange energies parameters,
structure dependent, the model provides a fairly consistent description of the thermodynamic properties as a function of concentration.
The interaction parameters, dispersive and quasichemical, depend on the intramolecular environment of the O atom. There is
clear evidence for the steric and inductive effects exerted by the alkyl groups adjacent to the O atom, for -O-C-O- proximity
effect and for a ring strain effect. The steric effect results in a regular decrease of the dispersive interaction parameters
of the oxygen/benzene (e,b) contact; The proximity effect of the O atoms produces a regular decrease and the ring strain a
regular increase of the dispersive interaction parameters; the quasi-chemical remain constant.