Para Hydrogen and HENDI

Background

Recently, we found that molecules in quantum condensed phases such as solid parahydrogen and superfluid He nanodroplets show completely quantized rotational energy levels, to which high-resolution spectroscopy can be applied. As a result, high-resolution spectroscopy of molecules in quantum condensed phases provides a powerful technique for detailed and precise investigation of their properties at the moderately low temperatures of 10 K – 0.1K. The research topics include investigation of intermolecular interactions, relaxation and decoherence processes, and chemical reaction dynamics at low temperatures-all of which are very difficult to obtain by other experimental techniques.

 

Long term goals

  • Improve our understanding of the origins of biological homochirality.
  • Characterize the behaviour of solid p-H2, as well as the behaviour of molecules trapped in solid p-H2.
  • Characterize photochemical processes of molecules trapped in solid p-H2.

Recent Work

  • The diffusion of water molecules within the solid p-H2 matrix was investigated. It was found that the diffusion of water within the p-H2 crystal behaved as diffusion of impurities within a quantum crystal.
  • The photochemistry of the simple amino acid alanine was investigated in solid p-H2 using Fourier-transform infrared spectroscopy. It was found that irradiation of alanine using 213 nm irradiation yields the HOCO radical, a radical of fundamental importance in interstellar chemistry.
  • The photolysis of matrix-isolated H2O using VUV irradiation was characterized. Hydroxyl radicals produced through photolysis of H2O react rapidly with the hydrogen matrix to produce new H2O molecules.

Current status

  • Characterization of the spectroscopic and photo-chemical behaviour of chiral molecules trapped in a solid p-H2 crystal at 4 K. The main goal of this work is to produce and characterize small chiral radicals through the photolysis of larger chiral molecules trapped within the hydrogen matrix. The study of small chiral radicals will hopefully yield additional information regarding the origins of biological homochirality.
  • Characterization of the photochemical behaviour of other molecules of fundamental chemical importance. Currently, the photochemistry of dichloromethane is being investigated, which is of particular interest in environmental atmospheric chemistry.
  • The properties of solid p-H2 is currently being investigated through the study of molecular diffusion within the solid p-H2 matrix.

Recent publications

    •  “Matrix Isolation Spectroscopy and Conformational Analysis of Epichlorohydrin in Solid Parahydrogen”
      Termeh Bashiri, Brendan Moore, Pavle Djuricanin, Takamasa Momose, J. Mol. Spectrosc.  in press (2021).
    • “VUV Photochemistry and Nuclear Spin Conversion of Water in Parahydrogen Crystals at 4 K”
      Fatemeh S. Tahsildaran F., Brendan Moore, Termeh Bashiri, Hatsuki Otani, Pavle Djuricanin, Rasoul Malekfar, Amir Hossein Farahbod, and Takamasa Momose,  PCCP  23, 4094-4106 (2021)
    •  “FTMW spectroscopy of epichlorohydrin: detection of three conformers”
      Yasuki Endo and Takamasa Momose,  J. Mol. Spectrosc. 372, 111348 (2020).
    • “UV photochemistry of 1,3-cyclohexadiene isolated in solid parahydrogen”
      Jun Miyazakia, Shin Yi Toh, Brendan Moore, Pavle Djuricanin, and Takamasa Momose,  J. Mol. Struct. 1224, 128986 (2020).
    • “Matrix isolation spectroscopy and spectral simulations of isotopically substituted C60 molecules”
      Tomonari Wakabayashi, Takamasa Momose, and Mario E. Fajardo,  J. Chem. Phys.  151, 234301 (2019)  18 pages.
    • “Stability and IR Spectroscopy of Zwitterionic Form of β‐Alanine in Water Clusters”
      Reyhaneh Ghassemizadeh, Brendan Moore, Takamasa Momose, and Michael Walter, J. Phys. Chem. B 123, 4392-4399 (2019).
    • “Diffusion of Water Molecules in Quantum Crystals”
      Brendan Moore, Pavle Djuricanin, and Takamasa Momose, J. Phys. Chem. Lett. 9, 6475-6479 (2018).
    •  “Ro-vibrational spectra of (para-H2)N-CH4 in He droplets”
      H. Hoshina, R. Sliter, A. Ravi, S. Kuma, T. Momose, and A. F. Vilesov, ChemPhysChem, 17, 3818- 3825  (2016).
    • “Longitudinal Spin Relaxation of Optically Pumped Rubidium Atoms in Solid Parahydrogen”,
      S. Upadhyay, A. N. Kanagin, C. Hartzell, T. Christy, W. P. Arnott, T. Momose, D. Patterson, and J. D. Weinstein, Phys. Rev. Lett. 117, 175301 (5 pages) (2016).
    •  “Ro-vibrational spectra of (para-H2)N-CH4 in He droplets”
      S. Upadhyay, A. N. Kanagin, C. Hartzell, T. Christy, W. P. Arnott, T. Momose, D. Patterson, and J. D. Weinstein, Phys. Rev. Lett. 117, 175301 (5 pages) (2016).
    • “Conformational Composition and Population Analysis of  β-alanine Isolated in Solid Parahydrogen and Argon Matrices”
      Y.T. Angel Wong, Shin Y. Toh, Pavle Djuricanin, and Takamasa Momose
      J. Mol. Spectrosc. 310, 23-31  (2015)
    • “UV Photochemistry of Benzene and Cyclohexadienyl Radical in Solid Parahydrogen”,
      Shin Yi Toh, Pavle Djuricanin, Takamasa Momose, and  Jun Miyazaki
      J. Phys Chem, A.  119(11) 2683-2691 (2015)