"Rotational And Vibrational Wave Packet Imaging Spectroscopy: Broad Bandwidth, High-resolution Spectra And Dynamics Of Weakly Bound Molecular Dimers, <span Class=""roman"">ar</span>_{<span Class=""roman"">2</span>}, (<span Class=""roman"">n</span><sub><s"

Mizuse, Kenta

Permalink

https://hdl.handle.net/2142/111473 Copy

Description

Title

"Rotational And Vibrational Wave Packet Imaging Spectroscopy: Broad Bandwidth, High-resolution Spectra And Dynamics Of Weakly Bound Molecular Dimers, ar₂, (n

Author(s)

Mizuse, Kenta

Contributor(s)

• Ohshima, Yasuhiro
• Tobata, Yuya
• Ishibashi, Genki
• Murai, Tomomi
• Oyagi, Yuhei
• Ishikawa, Haruki
• Sato, Hikaru

Issue Date

2021-06-24

Keyword(s)

Mini-symposium: Large Amplitude Motions

Abstract

We have developed a wave packet imaging-based, broad bandwidth, high-resolution spectroscopic method for weakly bound molecular dimers. In the present method, rotational and intermolecular vibrational wave packet motion is induced in the molecular dimer, via impulsive stimulated Raman scattering upon femtosecond, broad bandwidth pulse irradiation. The subsequent rotational/vibrational motion is observed as a molecular movie, utilizing time-resolved Coulomb explosion imaging. Rotational and vibrational Raman spectra are obtained as Fourier transform of the observed time-dependent image parameters. In our present setup, ~80 MHz frequency resolution and \textgreater 1 THz bandwidth are achieved simultaneously. We have measured high-resolution spectra of \chem{Ar_2}, (\chem{N_2})$_{2}$, and (\chem{CH_4})$_{2}$, while all of them are difficult targets for microwave spectroscopy due to their no or small permanent dipole. All measured spectra in the region of rotational transitions (\textless 150 GHz) show well-resolved structures. In the case of (\chem{N_2})$_{2}$ and (\chem{CH_4})$_{2}$, in which monomer units can rotate almost freely in the dimer, rotational constants vary with internal rotational states. This suggests internal motions govern the effective structures of the dimers. In addition to the rotational structure, the spectrum of (\chem{N_2})$_{2}$ shows a ~250 GHz oscillation, which can be attributed to the fundamental band of an intermolecular vibration. These results indicate that the present approach is a powerful approach to study large-amplitude intermolecular dynamics. Details of the experimental setup and spectral analyses will be presented.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

eng

Permalink

http://hdl.handle.net/2142/111473

DOI

10.15278/isms.2021.RH08

Owning Collections