On intramolecular and intermolecular hydrogen bonding

Intramolecular hydrogen bonding is often an important contribution to the o verall hydrogen bonding in fluid systems, especially in systems of biologic al interest. Of interest is the case of very dilute systems in inert solven ts where intermolecular hydrogen bonding is absent and the only observed hy drogen bonds are the intramolecular ones. The objective of this note is to present the necessary formalism in the frame of the lattice-fluid/hydrogen- bonding (LFHB) model(1) for studying fluid systems with both intermolecular and intramolecular hydrogen bonds. For simplicity, we will confine ourselv es to the case of molecules with one donor group (such as -OH) and x equiva lent proton acceptor sites (such as ether oxygen -O-) per molecule. This ty pe of system (polyethoxyalcohols) is of direct interest to the IUPAC projec t on alkanol-alkane-ether systems as they involve the same type of interact ions, and is of key importance in the study of non-ionic surfactants. The f ormalism can easily be extended to more complex cases. (C) 1999 Elsevier Sc ience B.V. All rights reserved.