Competition between hydrogen and halogen bonding in halogenated 1-methyluracil: water systems
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The competition between hydrogen- and halogen-bonding interactions in complexes of 5-halogenated 1-methyluracil (XmU; X = F, Cl, Br, I or At) with one or two water molecules in the binding region between C5-X and C4=O4 is investigated with M06-2X/6-31+G(d). In the singly-hydrated systems, the water molecule forms a hydrogen bond with C4=O4 for all halogens, whereas structures with a halogen bond between the water oxygen and C5-X exist only for X = Br, I and At. Structures with two waters forming a bridge between C4=O and C5-X (through hydrogen- and halogen-bonding interactions) exist for all halogens except F. The absence of a halogen-bonded structure in singly-hydrated ClmU is therefore attributed to the competing hydrogen-bonding interaction with C4=O4. The halogen-bond angle in the doubly-hydrated structures (150-160°) is far from the expected linearity of halogen bonds, indicating that significantly non-linear halogen bonds may exist in complex environments with competing interactions.
Hogan , S W L & van Mourik , T 2016 , ' Competition between hydrogen and halogen bonding in halogenated 1-methyluracil: water systems ' , Journal of Computational Chemistry , vol. 37 , no. 8 , pp. 763-770 . https://doi.org/10.1002/jcc.24264
Journal of Computational Chemistry
© 2016 Wiley Periodicals, Inc. This work is made available online in accordance with the publisher’s policies. This is the author created, accepted version manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at: https://dx.doi.org/10.1002/jcc.24264
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