Infrared Spectroscopy of Symmetric and Spherical Top Molecules for Space Observation, Volume 2

4Nanocages of Hydrate Clathrates

Nowadays, thanks to the techniques for the observation of the universe, the existence of gas hydrate clathrates in many cold media is an established fact in the astrophysics community.

In planetary systems, such as ours, for example, the gas hydrate clathrates (CO₂, CH₄, etc.) are present in many bodies, starting with our planet Earth, in marine sediments, permafrost and the underground lakes of the Antarctic. They could also exist below the surface of giant planets, on Titan (satellite of Saturn) or in the polar regions of the planet Mars.

In the cold regions of the interstellar medium, the observations revealed the presence of ice grains containing atoms, radicals, simple molecules, such as H₂, CO₂, CH₄ and NH₃, as well as more complex molecules.

Infrared spectroscopy is an investigation tool that can be used to obtain a large amount of information about the evolution of molecules in their medium, and hence understand the physico-chemical phenomena involved.

4.1. Introduction

The construction of the spectral profile (the shape and width of the spectral lines of a molecule trapped in a condensed medium) can be achieved, given the possibility of comparing theoretical results with high-resolution spectroscopy measurements.

For the CH₄ molecule trapped in a hydrate clathrate matrix, Dartois and his coworkers conducted a detailed experimental study using the Fourier transform infrared spectroscopy (FTIR) in the region of vibrational frequencies ...