HYDROGEN-BONDING COOPERATIVITY AND COMPETING INTER-MOLECULAR AND INTRAMOLECULAR ASSOCIATIONS - A UNIFIED APPROACH

Cooperativity in hydrogen bonding has been repeatedly invoked in the l iterature. Very often a distinction is made between the association co nstant for the ''dimer'' formation and the corresponding constant for the formation of association complexes beyond dimer. This work examine s this cooperativity hypothesis and proposes a straightforward manner of integrating it in the framework of the lattice-fluid hydrogen-bondi ng (LFHB) equation-of-state model. This integration is done without al tering the basic rationale of the LFHB model for the enumeration of hy drogen bond configurations for the self-association and cross-associat ion in the system. The model can accommodate hydrogen bond cooperativi ty in complex systems, even polymer mixtures forming three-dimensional networks of hydrogen bonds, and permits its study over an extended ra nge of temperatures and pressures. As additional examples of the appli cability of the method, the formation of cyclic associates and of intr amolecular hydrogen bonds is also examined.