skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Structural relaxation, viscosity, and network connectivity in a hydrogen bonding liquid

Abstract

The structure and dynamics of the model H-bonding liquid, n-methylacetamide (NMA) have been studied, revealing the connection between the timescale of H-bond network reorganization and viscosity.

Authors:
 [1];  [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1];  [1];  [2]; ORCiD logo [3];  [2]; ORCiD logo [2]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
  3. Shull Wollan Center; A Joint Institute for Neutron Sciences; Oak Ridge National Laboratory; Oak Ridge; USA
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1409250
Grant/Contract Number:
AC05-00OR22725
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Physical Chemistry Chemical Physics. PCCP (Print)
Additional Journal Information:
Journal Name: Physical Chemistry Chemical Physics. PCCP (Print); Journal Volume: 19; Journal Issue: 38; Journal ID: ISSN 1463-9076
Publisher:
Royal Society of Chemistry
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

Perticaroli, Stefania, Mostofian, Barmak, Ehlers, Georg, Neuefeind, Joerg C., Diallo, Souleymane Omar, Stanley, Christopher B., Daemen, Luke, Egami, Takeshi, Katsaras, John, Cheng, Xiaolin, and Nickels, Jonathan D. Structural relaxation, viscosity, and network connectivity in a hydrogen bonding liquid. United States: N. p., 2017. Web. doi:10.1039/c7cp04013j.
Perticaroli, Stefania, Mostofian, Barmak, Ehlers, Georg, Neuefeind, Joerg C., Diallo, Souleymane Omar, Stanley, Christopher B., Daemen, Luke, Egami, Takeshi, Katsaras, John, Cheng, Xiaolin, & Nickels, Jonathan D. Structural relaxation, viscosity, and network connectivity in a hydrogen bonding liquid. United States. doi:10.1039/c7cp04013j.
Perticaroli, Stefania, Mostofian, Barmak, Ehlers, Georg, Neuefeind, Joerg C., Diallo, Souleymane Omar, Stanley, Christopher B., Daemen, Luke, Egami, Takeshi, Katsaras, John, Cheng, Xiaolin, and Nickels, Jonathan D. 2017. "Structural relaxation, viscosity, and network connectivity in a hydrogen bonding liquid". United States. doi:10.1039/c7cp04013j.
@article{osti_1409250,
title = {Structural relaxation, viscosity, and network connectivity in a hydrogen bonding liquid},
author = {Perticaroli, Stefania and Mostofian, Barmak and Ehlers, Georg and Neuefeind, Joerg C. and Diallo, Souleymane Omar and Stanley, Christopher B. and Daemen, Luke and Egami, Takeshi and Katsaras, John and Cheng, Xiaolin and Nickels, Jonathan D.},
abstractNote = {The structure and dynamics of the model H-bonding liquid, n-methylacetamide (NMA) have been studied, revealing the connection between the timescale of H-bond network reorganization and viscosity.},
doi = {10.1039/c7cp04013j},
journal = {Physical Chemistry Chemical Physics. PCCP (Print)},
number = 38,
volume = 19,
place = {United States},
year = 2017,
month = 7
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on July 21, 2018
Publisher's Version of Record

Save / Share:
  • The methyltetrahydrofolate (CH{sub 3}-H{sub 4}folate) corrinoid-ironsulfur protein (CFeSP) methyltransferase (MeTr) catalyzes transfer of the methyl group of CH3-H4folate to cob(I)amide. This key step in anaerobic CO and CO{sub 2} fixation is similar to the first half-reaction in the mechanisms of other cobalamin-dependent methyltransferases. Methyl transfer requires electrophilic activation of the methyl group of CH{sub 3}-H{sub 4}folate, which includes proton transfer to the N5 group of the pterin ring and poises the methyl group for reaction with the Co(I) nucleophile. The structure of the binary CH{sub 3}-H{sub 4}folate/MeTr complex (revealed here) lacks any obvious proton donor near the N5 group. Instead,more » an Asn residue and water molecules are found within H-bonding distance of N5. Structural and kinetic experiments described here are consistent with the involvement of an extended H-bonding network in proton transfer to N5 of the folate that includes an Asn (Asn-199 in MeTr), a conserved Asp (Asp-160), and a water molecule. This situation is reminiscent of purine nucleoside phosphorylase, which involves protonation of the purine N7 in the transition state and is accomplished by an extended H-bond network that includes water molecules, a Glu residue, and an Asn residue (Kicska, G. A., Tyler, P. C., Evans, G. B., Furneaux, R. H., Shi, W., Fedorov, A., Lewandowicz, A., Cahill, S. M., Almo, S. C., and Schramm, V. L. (2002) Biochemistry 41, 14489-14498). In MeTr, the Asn residue swings from a distant position to within H-bonding distance of the N5 atom upon CH{sub 3}-H{sub 4}folate binding. An N199A variant exhibits only {approx}20-fold weakened affinity for CH{sub 3}-H{sub 4}folate but a much more marked 20,000-40,000-fold effect on catalysis, suggesting that Asn-199 plays an important role in stabilizing a transition state or high energy intermediate for methyl transfer.« less
  • No abstract prepared.
  • No abstract prepared.
  • The network connectivity in liquid water is revised in terms of electronic signatures of hydrogen bonds (HBs) instead of geometric criteria, in view of recent x-ray absorption studies. The analysis is based on ab initio molecular-dynamics simulations at ambient conditions. Even if instantaneous threadlike structures are observed in the electronic network, they continuously reshape in oscillations reminiscent of the r and t modes in ice ({tau}{approx}170 fs). However, two water molecules initially joined by a HB remain effectively bound over many periods regardless of its electronic signature.