Computational study of the patterns of weaker intramolecular hydrogen bonds stabilizing acylphloroglucinols

Acylphloroglucinols (ACPLs) are polyphenolic compounds derivative from phloroglucinol, characterized by the presence of at least one COR group and exhibiting a variety of biological activities, which makes them interesting for drug development possibilities. This study investigates patterns in the ways in which weaker intramolecular hydrogen bonds contribute to their conformational stabilization, considering the C? H···O H‐bonds, present in all ACPLs, and the O? H···π H‐bonds, present in ACPLs in which one or more substituents contain a π bond or system sufficiently close to a phenol OH for the H‐bond to be possible. The results in vacuo and in three different solvents (chloroform, acetonitrile, and water) show that, whereas C? H···O plays a significant roles in all these media, the role of O? H···π decreases with increasing solvent polarity. Calculations in vacuo are performed at various levels to enable performance comparisons; calculations in solution use the polarizable continuum model. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011