Theoretical Study of Multidimensional Proton Tunnelling in Benzoic Acid Dimer
Abstract: Ab initio B3LYP/6-311++G** calculations have been carried out for the benzoic acid dimer for the stable and saddle point structures. The energy barrier for the proton tunneling amounts to 6.5 kcal/mol. The normal mode frequencies have been computed including modes coupled to the proton tun...
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| Format: | Article |
| Language: | English |
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MDPI AG
2003-06-01
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| Series: | International Journal of Molecular Sciences |
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| Online Access: | http://www.mdpi.com/1422-0067/4/7/422/ |
| _version_ | 1811221381462884352 |
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| author | Marek Boczar Krzysztof Szczeponek Marek J. Wójcik |
| author_facet | Marek Boczar Krzysztof Szczeponek Marek J. Wójcik |
| author_sort | Marek Boczar |
| collection | DOAJ |
| description | Abstract: Ab initio B3LYP/6-311++G** calculations have been carried out for the benzoic acid dimer for the stable and saddle point structures. The energy barrier for the proton tunneling amounts to 6.5 kcal/mol. The normal mode frequencies have been computed including modes coupled to the proton tunneling mode. Two-dimensional model potentials, formed from symmetric mode coupling potential and squeezed double well potential, have been fitted to the calculated energy barrier, geometries and frequencies, and used to analyze proton dynamics. The calculated proton tunneling energy splitting in the vibrationally ground states of the low-frequency modes is ~230 cm-1. The two-dimensional model PES predict monotonic increase of the tunneling splitting with the excitation of the planar modes. Depending of the sign of the coupling parameter out-of-plane modes can either suppress or promote the splittings. |
| first_indexed | 2024-04-12T07:58:18Z |
| format | Article |
| id | doaj.art-faecc7da14314e26844bec2ff31a1a9c |
| institution | Directory Open Access Journal |
| issn | 1422-0067 |
| language | English |
| last_indexed | 2024-04-12T07:58:18Z |
| publishDate | 2003-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | International Journal of Molecular Sciences |
| spelling | doaj.art-faecc7da14314e26844bec2ff31a1a9c2022-12-22T03:41:25ZengMDPI AGInternational Journal of Molecular Sciences1422-00672003-06-014742243310.3390/i4070422Theoretical Study of Multidimensional Proton Tunnelling in Benzoic Acid DimerMarek BoczarKrzysztof SzczeponekMarek J. WójcikAbstract: Ab initio B3LYP/6-311++G** calculations have been carried out for the benzoic acid dimer for the stable and saddle point structures. The energy barrier for the proton tunneling amounts to 6.5 kcal/mol. The normal mode frequencies have been computed including modes coupled to the proton tunneling mode. Two-dimensional model potentials, formed from symmetric mode coupling potential and squeezed double well potential, have been fitted to the calculated energy barrier, geometries and frequencies, and used to analyze proton dynamics. The calculated proton tunneling energy splitting in the vibrationally ground states of the low-frequency modes is ~230 cm-1. The two-dimensional model PES predict monotonic increase of the tunneling splitting with the excitation of the planar modes. Depending of the sign of the coupling parameter out-of-plane modes can either suppress or promote the splittings.http://www.mdpi.com/1422-0067/4/7/422/proton tunnellingenergy barriertunnelling splittings |
| spellingShingle | Marek Boczar Krzysztof Szczeponek Marek J. Wójcik Theoretical Study of Multidimensional Proton Tunnelling in Benzoic Acid Dimer International Journal of Molecular Sciences proton tunnelling energy barrier tunnelling splittings |
| title | Theoretical Study of Multidimensional Proton Tunnelling in Benzoic Acid Dimer |
| title_full | Theoretical Study of Multidimensional Proton Tunnelling in Benzoic Acid Dimer |
| title_fullStr | Theoretical Study of Multidimensional Proton Tunnelling in Benzoic Acid Dimer |
| title_full_unstemmed | Theoretical Study of Multidimensional Proton Tunnelling in Benzoic Acid Dimer |
| title_short | Theoretical Study of Multidimensional Proton Tunnelling in Benzoic Acid Dimer |
| title_sort | theoretical study of multidimensional proton tunnelling in benzoic acid dimer |
| topic | proton tunnelling energy barrier tunnelling splittings |
| url | http://www.mdpi.com/1422-0067/4/7/422/ |
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