Exploring the Non-Covalent Bonding in Water Clusters
QTAIM and source function analysis were used to explore the non-covalent bonding in twelve different water clusters (H<sub>2</sub>O)<i><sub>n</sub></i> obtained by considering <i>n</i> = 2–7 and various geometrical arrangements. A total of seventy-seve...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-03-01
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| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/24/6/5271 |
| Summary: | QTAIM and source function analysis were used to explore the non-covalent bonding in twelve different water clusters (H<sub>2</sub>O)<i><sub>n</sub></i> obtained by considering <i>n</i> = 2–7 and various geometrical arrangements. A total of seventy-seven O−H⋯O hydrogen bonds (HBs) were identified in the systems under consideration, and the examination of the electron density at the bond critical point (BCP) of these HBs revealed the existence of a great diversity of O−H⋯O interactions. Furthermore, the analysis of quantities, such as <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mrow><mo>|</mo><mrow><mi>V</mi><mrow><mo>(</mo><mstyle mathvariant="bold" mathsize="normal"><mi>r</mi></mstyle><mo>)</mo></mrow></mrow><mo>|</mo></mrow><mo>/</mo><mi>G</mi><mrow><mo>(</mo><mstyle mathvariant="bold" mathsize="normal"><mi>r</mi></mstyle><mo>)</mo></mrow></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>H</mi><mrow><mo>(</mo><mstyle mathvariant="bold" mathsize="normal"><mi>r</mi></mstyle><mo>)</mo></mrow></mrow></semantics></math></inline-formula>, allowed a further description of the nature of analogous O−H⋯O interactions within each cluster. In the case of 2-D cyclic clusters, the HBs are nearly equivalent between them. However, significant differences among the O−H⋯O interactions were observed in 3-D clusters. The assessment of the source function (SF) confirmed these findings. Finally, the ability of SF to decompose the electron density (<i>ρ</i>) into atomic contributions allowed the evaluation of the localized or delocalized character of these contributions to <i>ρ</i> at the BCP associated to the different HBs, revealing that weak O−H⋯O interactions have a significant spread of the atomic contributions, whereas strong interactions have more localized atomic contributions. These observations suggest that the nature of the O−H⋯O hydrogen bond in water clusters is determined by the inductive effects originated by the different spatial arrangements of the water molecules in the studied clusters. |
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| ISSN: | 1661-6596 1422-0067 |