Hydrogen bond interactions in small covalent model compounds (i.e. deprotonated polyhydroxy alcohols) were measured by negative ion photoelectron spectroscopy. The experimentally determined vertical and adiabatic electron detachment energies for (HOCH2CH2)2CHO (2a), (HOCH2CH2) 3CO (3a) and (HOCH2CH2CH(OH)CH2)3CO (4a) reveal that hydrogen-bonded networks can provide enormous stabilizations, and that a single charge center not only can be stabilized by up to 3 hydrogen bonds but it can increase the interaction energy between non-charged OH groups by 5.8 kcal mol1 or more per hydrogen bond. This can lead to pKa values that are very different than in water, and provide some of the impetus for catalytic processes.
Revised: September 11, 2013 |
Published: February 1, 2012
Citation
Shokri A., J.C. Schmidt, X.B. Wang, and S.R. Kass. 2012.Hydrogen Bonded Arrays: The Power of Multiple Hydrogen Bonds.Journal of the American Chemical Society 134, no. 4:2094-2099.PNNL-SA-82915.doi:10.1021/ja2081907