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Journal article
A closer examination of the coupling between ionic hydrogen bond (IHB) stretching and flanking group motions in (CH3OH)2H+: the strong isotope effects
Physical chemistry chemical physics : PCCP, Vol.18(21), pp.14531-14542
06/07/2016
PMID: 27173598
Web of Science ID: WOS:000378102700047
Abstract
The intermode coupling between shared proton (O-H+-O) fundamental stretching and flanking modes in (CH3OH)(2)H+ was revisited in the following contexts: (1) evaluation of Hamiltonian matrix elements represented in a "pure state" (PS) basis and (2) tuning of coupling strengths using H/D isotopic substitution. We considered four experimentally accessible isotopologues for this study. These are: (CH3OH)(2)H+, (CD3OH)(2)H+, (CH3OD)(2)D+, and (CD3OD)(2)D+. Potential energy surfaces (PESs), as well as dipole moment surfaces (DMSs), were constructed at the MP2/aug-cc-pVDZ level. Multidimensional vibrational calculations were conducted by solving a reduced dimensional Schrodinger equation using a discrete variable representation (DVR). We found that vibrational states in (CH3OH)(2)H+ and (CD3OH)(2)H+ are much more heavily mixed than those in (CH3OD)(2)D+ and (CD3OD)(2)D+. Furthermore, each isotopologue chooses to strongly couple between out-of-phase in-plane CH3 rocking and its out-of-plane counterpart. Lastly, the interaction between O-O stretching and O-H+-O stretching was explored. We found that between the first overtone of O-O stretching and its combination tone with O-H+-O fundamental stretching, only the second couples with O-H+-O fundamental stretching. We hope that our isotopologue calculations would motivate experimentalists to measure them in the future.
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Details
- Title
- A closer examination of the coupling between ionic hydrogen bond (IHB) stretching and flanking group motions in (CH3OH)2H+: the strong isotope effects
- Publication Details
- Physical chemistry chemical physics : PCCP, Vol.18(21), pp.14531-14542
- Resource Type
- Journal article
- Publisher
- Royal Society of Chemistry
- Number of pages
- 12
- Grant note
- Ministry of Science and Technology (MOST) of Taiwan: MOST101-2113-M-001-023-MY3, MOST104-2113-M-001-017 Taiwan International Graduate Program (TIGP)Academia Sinica
This work was financially supported by Academia Sinica and the Ministry of Science and Technology (MOST) of Taiwan under various grants (MOST101-2113-M-001-023-MY3 and MOST104-2113-M-001-017). JAT would like to thank Taiwan International Graduate Program (TIGP) for scholarship and MOST for travel support (MOST-103-29224-I-007-213). Computational resources are supported in part by the National Center for High-Performance Computing (NCHC). We wish to thank Prof. Yonggang Yang, Dr Kaito Takahashi and Dr Kopin Liu for the fruitful discussions related to this project. We would like to express our gratitude to Mr Jheng-Wei Li for the DVR scanner and Dr Masato Morita for the DVR solver. We are also grateful to Prof. Mark A. Johnson of Yale University for providing the experimental Ar-tagged action spectrum.
- Identifiers
- WOS:000378102700047; 99381548018806600
- Academic Unit
- Chemistry; Hal Marcus College of Science and Engineering
- Language
- English