Hydrogen-bond networks: Strengths of different types of hydrogen bonds and an alternative to the low barrier hydrogen-bond proposal

Alireza Shokri, Yanping Wang, George A. O'Doherty, Xue Bin Wang, Steven R. Kass

Research output: Contribution to journalArticle

34 Scopus citations

Abstract

We report quantifying the strengths of different types of hydrogen bonds in hydrogen-bond networks (HBNs) via measurement of the adiabatic electron detachment energy of the conjugate base of a small covalent polyol model compound (i.e., (HOCH2CH2CH(OH)CH2) 2CHOH) in the gas phase and the pKa of the corresponding acid in DMSO. The latter result reveals that the hydrogen bonds to the charged center and those that are one solvation shell further away (i.e., primary and secondary) provide 5.3 and 2.5 pKa units of stabilization per hydrogen bond in DMSO. Computations indicate that these energies increase to 8.4 and 3.9 pKa units in benzene and that the total stabilizations are 16 (DMSO) and 25 (benzene) pKa units. Calculations on a larger linear heptaol (i.e., (HOCH2CH2CH(OH)CH2CH(OH)CH 2)2CHOH) reveal that the terminal hydroxyl groups each contribute 0.6 pKa units of stabilization in DMSO and 1.1 pK a units in benzene. All of these results taken together indicate that the presence of a charged center can provide a powerful energetic driving force for enzyme catalysis and conformational changes such as in protein folding due to multiple hydrogen bonds in a HBN.

Original languageEnglish (US)
Pages (from-to)17919-17924
Number of pages6
JournalJournal of the American Chemical Society
Volume135
Issue number47
DOIs
StatePublished - Nov 27 2013

Fingerprint Dive into the research topics of 'Hydrogen-bond networks: Strengths of different types of hydrogen bonds and an alternative to the low barrier hydrogen-bond proposal'. Together they form a unique fingerprint.

  • Cite this