Stevens, JS, Byard, SJ, Seaton, CC et al. (3 more authors) (2014) Proton transfer and hydrogen bonding in the organic solid state: a combined XRD/XPS/ssNMR study of 17 organic acid–base complexes. Physical Chemistry Chemical Physics, 16 (3). pp. 1150-1160. ISSN 1463-9076
Abstract
The properties of nitrogen centres acting either as hydrogen-bond or Brønsted acceptors in solid molecular acid-base complexes have been probed by N 1s X-ray photoelectron spectroscopy (XPS) as well as 15N solid-state nuclear magnetic resonance (ssNMR) spectroscopy and are interpreted with reference to local crystallographic structure information provided by X-ray diffraction (XRD). We have previously shown that the strong chemical shift of the N 1s binding energy associated with the protonation of nitrogen centres unequivocally distinguishes protonated (salt) from hydrogen-bonded (co-crystal) nitrogen species. This result is further supported by significant ssNMR shifts to low frequency, which occur with proton transfer from the acid to the base component. Generally, only minor chemical shifts occur upon co-crystal formation, unless a strong hydrogen bond is formed. CASTEP density functional theory (DFT) calculations of 15N ssNMR isotropic chemical shifts correlate well with the experimental data, confirming that computational predictions of H-bond strengths and associated ssNMR chemical shifts allow the identification of salt and co-crystal structures (NMR crystallography). The excellent agreement between the conclusions drawn by XPS and the combined CASTEP/ssNMR investigations opens up a reliable avenue for local structure characterization in molecular systems even in the absence of crystal structure information, for example for non-crystalline or amorphous matter. The range of 17 different systems investigated in this study demonstrates the generic nature of this approach, which will be applicable to many other molecular materials in organic, physical, and materials chemistry
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2014, The Author(s). This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 03 Feb 2015 14:12 |
Last Modified: | 27 Oct 2020 16:20 |
Published Version: | http://dx.doi.org./10.1039/c3cp53907e |
Status: | Published |
Publisher: | Royal Society of Chemistry |
Identification Number: | 10.1039/c3cp53907e |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:82533 |