A team of scientists led by University of HawaiÊ»i at MÄ�noa Professor Ralf Kaiser has discovered a new possible pathway toward forming carbon structures in space using a specialized chemical exploration technique at the Department of Energyâ€™s Lawrence Berkeley National Laboratory (Berkeley Labâ€™s Advanced Light Source). The team also included computational chemists from Florida International University.
In the study, published in Nature Communications, researchers produced a ringed, carbon-containing molecule by combining two highly reactive chemical species that are called free radicals because they contain unpaired electrons.
The teamâ€™s research has now identified several key avenues by which ringed molecules known as polycyclic aromatic hydrocarbons, or PAHs, can form in space.
PAHsâ€”which also occur on Earth in emissions and soot from the combustion of fossil fuelsâ€”could provide clues to the formation of lifeâ€™s chemistry in space as precursors to interstellar nanoparticles.
The study ultimately showed how these chemical processes could lead to the development of carbon-containing graphene-type PAHs and 2D nanostructures. Graphene is a one-dimensional layer of fused hexagons consisting of carbon atoms.
â€œThis is something that people have tried to measure experimentally at high temperatures for decades but have not done successfully before,â€� said Musahid Ahmed, a scientist in Berkeley Labâ€™s Chemical Sciences Division. â€œ We believe this is yet another pathway that can give rise to PAHs.â€�
Kaiser added, â€œThe present experiment clearly provides scientific evidence that reactions between radicals at elevated temperatures do form aromatic molecules such as naphthalene.â€�
The latest study is part of an ongoing effort of the HawaiÊ»i-Berkeley-Florida team to retrace the chemical steps leading to the formation of complex carbon-containing molecules in deep space up to all-carbon-containing soccer-shaped buckyball molecules.