Dalian coherent light source reveals the origin of interstellar medium S2 fragments

January 28, 2021

Studying the creation and evolution of sulfur-containing compounds in outer space is essential for understanding interstellar chemistry. CS2 is believed to be the most important molecule in comet nuclei, interstellar dust, or ice cores. CS and S2 are the photodissociation fragments of CS2.

Forty years ago, the emission spectra of only CS and S2 species, and not those of CS2 species, were observed from several comets by the International Ultraviolet Explorer satellite. The photodissociation mechanism of CS2 molecules remains unclear, and S2 fragments have not been experimentally observed before.

Recently, a team led by Prof. YUAN Kaijun from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), in cooperation with Prof. WANG Xing'an's group from the University of Science and Technology of China, observed the C+S2 product channel from CS2 photodissociation for the first time using a home-made Time-Sliced Velocity Map Ion Imaging (TS-VMI) experimental setup, based on the Dalian Coherent Light Source (DCLS).

This study, published in The Journal of Physical Chemistry Letters on January 11 2021, provided direct experimental evidence for the origin of the interstellar medium S2 fragments observed previously.

The researchers investigated the two-photon ultraviolet (UV) and one-photon vacuum ultraviolet (VUV) photodissociation dynamics of CS2 molecules via the VUV free-electron laser (FEL) at DCLS. They directly observed the C+S2 product channel from CS2 photodissociation and obtained images of the electronically ground/excited states of S2 products with vibrational excitation.

Moreover, the researchers analyzed the product scattering anisotropy parameter β value. The electronically-excited states of the central atom of the CS2 molecule played an important role in the isomerization and photodissociation processes.

This research demonstrated that interstellar medium S2 fragments could be directly generated from CS2 photodissociation.

"Given the similarity of OCS studied in our previous works and CS2 in this work, we believe that the central-atom elimination channel is more general than expected in the photodissociation of triatomic molecules," stated Prof YUAN.
-end-
This work was supported by the Chemical Dynamics Research Center, the National Natural Science Foundation of China, and the Key Technology Team of CAS.

Dalian Institute of Chemical Physics, Chinese Academy Sciences

Related Molecules Articles from Brightsurf:

Finally, a way to see molecules 'wobble'
Researchers at the University of Rochester and the Fresnel Institute in France have found a way to visualize those molecules in even greater detail, showing their position and orientation in 3D, and even how they wobble and oscillate.

Water molecules are gold for nanocatalysis
Nanocatalysts made of gold nanoparticles dispersed on metal oxides are very promising for the industrial, selective oxidation of compounds, including alcohols, into valuable chemicals.

Water molecules dance in three
An international team of scientists has been able to shed new light on the properties of water at the molecular level.

How molecules self-assemble into superstructures
Most technical functional units are built bit by bit according to a well-designed construction plan.

Breaking down stubborn molecules
Seawater is more than just saltwater. The ocean is a veritable soup of chemicals.

Shaping the rings of molecules
Canadian chemists discover a natural process to control the shape of 'macrocycles,' molecules of large rings of atoms, for use in pharmaceuticals and electronics.

The mysterious movement of water molecules
Water is all around us and essential for life. Nevertheless, research into its behaviour at the atomic level -- above all how it interacts with surfaces -- is thin on the ground.

Spectroscopy: A fine sense for molecules
Scientists at the Laboratory for Attosecond Physics have developed a unique laser technology for the analysis of the molecular composition of biological samples.

Looking at the good vibes of molecules
Label-free dynamic detection of biomolecules is a major challenge in live-cell microscopy.

Colliding molecules and antiparticles
A study by Marcos Barp and Felipe Arretche from Brazil published in EPJ D shows a model of the interaction between positrons and simple molecules that is in good agreement with experimental results.

Read More: Molecules News and Molecules Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.