### Abstrakti

The changes in the computed nuclear magnetic

resonance (NMR) parameters of the water dimer with

respect to their monomer values were monitored as the

geometry of the dimer was systematically varied. Nuclear

magnetic shielding constants, shielding tensor anisotropies,

nuclear quadrupole coupling constants and spin–spin coupling

constants for the hydrogen bond donor and acceptor

molecules were calculated at hybrid density-functional

theory level. The dimer geometry was specified through

the intermolecular oxygen–oxygen distance ROO and the

hydrogen bond angle a. A grid of 120 geometries was

selected by systematically varying these two parameters.

The other geometrical parameters of the dimer were allowed

to relax, keeping the two parameters fixed. As the dimer

geometry was varied, all NMR parameters were observed to

be smoothly behaving. Characteristic changes as a function

of the intermolecular geometry were observed. These

include, besides the well-known deshielding of the donor

hydrogen shielding constant, also influences on the donor

deuterium quadrupole coupling constant, as well as the

shielding anisotropy of the donor and acceptor oxygens. We

discuss the contributions to the total dimerisation effect

from, on the one hand, the dominant direct interaction effect

at a fixed geometry and, on the other hand, from the quantitatively

relevant indirect, geometric effect. A fundamental

ambiguity of this partitioning is demonstrated. By forging

the general, smooth trends in all the studied NMR parameters

into a specific geometric definition, we find our data

to be in agreement with the widely used distance criterion for

hydrogen bonding in water, ROO B 3.5 A ° .

resonance (NMR) parameters of the water dimer with

respect to their monomer values were monitored as the

geometry of the dimer was systematically varied. Nuclear

magnetic shielding constants, shielding tensor anisotropies,

nuclear quadrupole coupling constants and spin–spin coupling

constants for the hydrogen bond donor and acceptor

molecules were calculated at hybrid density-functional

theory level. The dimer geometry was specified through

the intermolecular oxygen–oxygen distance ROO and the

hydrogen bond angle a. A grid of 120 geometries was

selected by systematically varying these two parameters.

The other geometrical parameters of the dimer were allowed

to relax, keeping the two parameters fixed. As the dimer

geometry was varied, all NMR parameters were observed to

be smoothly behaving. Characteristic changes as a function

of the intermolecular geometry were observed. These

include, besides the well-known deshielding of the donor

hydrogen shielding constant, also influences on the donor

deuterium quadrupole coupling constant, as well as the

shielding anisotropy of the donor and acceptor oxygens. We

discuss the contributions to the total dimerisation effect

from, on the one hand, the dominant direct interaction effect

at a fixed geometry and, on the other hand, from the quantitatively

relevant indirect, geometric effect. A fundamental

ambiguity of this partitioning is demonstrated. By forging

the general, smooth trends in all the studied NMR parameters

into a specific geometric definition, we find our data

to be in agreement with the widely used distance criterion for

hydrogen bonding in water, ROO B 3.5 A ° .

Alkuperäiskieli | englanti |
---|---|

Lehti | Theoretical Chemistry Accounts |

Vuosikerta | 129 |

Numero | 3-5 |

Sivut | 313-324 |

Sivumäärä | 12 |

ISSN | 1432-881X |

DOI - pysyväislinkit | |

Tila | Julkaistu - 2011 |

OKM-julkaisutyyppi | A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä, vertaisarvioitu |

### Tieteenalat

- 116 Kemia
- 114 Fysiikka

## Siteeraa tätä

Pennanen, T. S., Lantto, P., Hakala, M. O., & Vaara, J. (2011). Nuclear magnetic resonance parameters in water dimer.

*Theoretical Chemistry Accounts*,*129*(3-5), 313-324. https://doi.org/10.1007/s00214-010-0782-y