31. Brinkley, Ray L.; Gupta, Ram B. Hydrogen bonding with aromatic rings. AIChE J. (2001), 47(4), 948-953.
Thermodn. effects of hydrogen bonding are important in detg. the phase behavior in polar fluids. While efforts to understand "strong" donor and "strong" acceptor combinations (H-bonds involving a formation energy more neg. than - 20 kJ/mol such as alkanol-alkanol H-bonding have been substantial, weak H-bonds involving double bonds or arom. rings as proton acceptors) have largely been ignored. Using FTIR spectroscopy H-bonding between alc. donor and arom. ring-contg. acceptor mols. was studied including l-hexanol and cyclohexanol at low concns. where self-assocn. is negligible (strong donors). H-bonding "weak" acceptors studied include toluene and m-xylene. Clear spectroscopic evidence existed for the formation of H-bonds between the alc. and arom. mols., which are much weaker than conventional "strong donor"-"strong acceptor" H-bonds. Using quant. FTIR measurements, the percentage of H-bonded alc. mols. over a range of arom. concns. was detd. Ab initio calcns. also showed that alc.-arom. H-bonds are much weaker than alc.-alc. H-bonds. This H-bonding, though weak, will contribute significantly to the chem. potential of the mols.