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Low-Barrier Hydrogen Bonds in Negative Thermal Expansion Material H 3 [Co(CN) 6 ]

Tolborg, Kasper ; Jørgensen, Mads R.V. LU orcid ; Sist, Mattia ; Mamakhel, Aref ; Overgaard, Jacob and Iversen, Bo B. (2019) In Chemistry - A European Journal 25(27). p.6814-6822
Abstract


The covalent nature of the low-barrier N−H−N hydrogen bonds in the negative thermal expansion material H
3
[Co(CN)
6
] has been established by using a combination of X-ray and neutron diffraction electron density analysis and theoretical calculations. This finding explains why negative thermal expansion can occur in a material not commonly considered to be built from rigid linkers. The pertinent hydrogen atom is... (More)


The covalent nature of the low-barrier N−H−N hydrogen bonds in the negative thermal expansion material H
3
[Co(CN)
6
] has been established by using a combination of X-ray and neutron diffraction electron density analysis and theoretical calculations. This finding explains why negative thermal expansion can occur in a material not commonly considered to be built from rigid linkers. The pertinent hydrogen atom is located symmetrically between two nitrogen atoms in a double-well potential with hydrogen above the barrier for proton transfer, thus forming a low-barrier hydrogen bond. Hydrogen is covalently bonded to the two nitrogen atoms, which is the first experimentally confirmed covalent hydrogen bond in a network structure. Source function calculations established that the present N−H−N hydrogen bond follows the trends observed for negatively charge-assisted hydrogen bonds and low-barrier hydrogen bonds previously established for O−H−O hydrogen bonds. The bonding between the cobalt and cyanide ligands was found to be a typical donor–acceptor bond involving a high-field ligand and a transition metal in a low-spin configuration.

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author
; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
chemical bonding, electron density, hydrogen bonds, neutron diffraction, X-ray diffraction
in
Chemistry - A European Journal
volume
25
issue
27
pages
9 pages
publisher
Wiley-Blackwell
external identifiers
  • scopus:85065208617
  • pmid:30821859
ISSN
0947-6539
DOI
10.1002/chem.201900358
language
English
LU publication?
yes
id
00686d66-d789-40cc-b849-81dcaa508972
date added to LUP
2019-05-24 11:58:11
date last changed
2025-10-14 10:03:29
@article{00686d66-d789-40cc-b849-81dcaa508972,
  abstract     = {{<p><br>
                                                         The covalent nature of the low-barrier N−H−N hydrogen bonds in the negative thermal expansion material H                             <br>
                            <sub>3</sub><br>
                                                         [Co(CN)                             <br>
                            <sub>6</sub><br>
                                                         ] has been established by using a combination of X-ray and neutron diffraction electron density analysis and theoretical calculations. This finding explains why negative thermal expansion can occur in a material not commonly considered to be built from rigid linkers. The pertinent hydrogen atom is located symmetrically between two nitrogen atoms in a double-well potential with hydrogen above the barrier for proton transfer, thus forming a low-barrier hydrogen bond. Hydrogen is covalently bonded to the two nitrogen atoms, which is the first experimentally confirmed covalent hydrogen bond in a network structure. Source function calculations established that the present N−H−N hydrogen bond follows the trends observed for negatively charge-assisted hydrogen bonds and low-barrier hydrogen bonds previously established for O−H−O hydrogen bonds. The bonding between the cobalt and cyanide ligands was found to be a typical donor–acceptor bond involving a high-field ligand and a transition metal in a low-spin configuration.                         <br>
                        </p>}},
  author       = {{Tolborg, Kasper and Jørgensen, Mads R.V. and Sist, Mattia and Mamakhel, Aref and Overgaard, Jacob and Iversen, Bo B.}},
  issn         = {{0947-6539}},
  keywords     = {{chemical bonding; electron density; hydrogen bonds; neutron diffraction; X-ray diffraction}},
  language     = {{eng}},
  number       = {{27}},
  pages        = {{6814--6822}},
  publisher    = {{Wiley-Blackwell}},
  series       = {{Chemistry - A European Journal}},
  title        = {{Low-Barrier Hydrogen Bonds in Negative Thermal Expansion Material H                         
                        <sub>3</sub>
                                                 [Co(CN)                         
                        <sub>6</sub>
                                                 ]}},
  url          = {{http://dx.doi.org/10.1002/chem.201900358}},
  doi          = {{10.1002/chem.201900358}},
  volume       = {{25}},
  year         = {{2019}},
}