Cooperativity between the Halogen Bond and the Hydrogen Bond in H3N⋅⋅⋅XY⋅⋅⋅HF Complexes (X,Y=F,Cl, Br) |
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Authors: | Qingzhong Li Dr. Qingquan Lin Wenzuo Li Jianbo Cheng Baoan Gong Jiazhong Sun |
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Affiliation: | The Laboratory of Theoretical and Computational Chemistry, Science and Engineering College of Chemistry and Biology, Yantai University, Yantai 264005 (P. R. China), Fax: (+86)?535‐6902063 |
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Abstract: | Ab initio calculations are used to provide information on H3N???XY???HF triads (X, Y=F, Cl, Br) each having a halogen bond and a hydrogen bond. The investigated triads include H3N???Br2‐HF, H3N???Cl2???HF, H3N???BrCI???HF, H3N???BrF???HF, and H3N???ClF???HF. To understand the properties of the systems better, the corresponding dyads are also investigated. Molecular geometries, binding energies, and infrared spectra of monomers, dyads, and triads are studied at the MP2 level of theory with the 6‐311++G(d,p) basis set. Because the primary aim of this study is to examine cooperative effects, particular attention is given to parameters such as cooperative energies, many‐body interaction energies, and cooperativity factors. The cooperative energy ranges from ?1.45 to ?4.64 kcal mol?1, the three‐body interaction energy from ?2.17 to ?6.71 kcal mol?1, and the cooperativity factor from 1.27 to 4.35. These results indicate significant cooperativity between the halogen and hydrogen bonds in these complexes. This cooperativity is much greater than that between hydrogen bonds. The effect of a halogen bond on a hydrogen bond is more pronounced than that of a hydrogen bond on a halogen bond. |
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Keywords: | ab initio calculations halogen bonds halogens hydrogen bonding IR spectroscopy |
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