Space: The final frontier in silicon chemistry

November 11, 2014, American Institute of Physics
Schematic figure of the present experiment. Reactive molecules produced in a supersonic jet come into the microwave cavity placed inside a vacuum chamber, where microwave radiation excites the molecules. Induced microwave radiation from the excited molecules is detected. Credit: Yasuki Endo/ The University of Tokyo

Silicon, which is one of the most common elements in the Earth's crust, is also sprinkled abundantly throughout interstellar space. The only way to identify silicon-containing molecules in the far corners of the cosmos - and to understand the chemistry that created them - is to observe through telescopes the electromagnetic radiation the molecules emit.

Scientists from the University of Tokyo, in Japan, have now determined the unique electromagnetic emission spectrums of two new, highly-reactive . The research, which is published in The Journal of Chemical Physics from AIP Publishing, will help astronomers look for the in the .

"Like human fingerprints and DNA sequences are the markers of human identity, we can identify molecules from the frequencies of the electromagnetic waves emitted by them," said Yasuki Endo, a researcher in the Department of Basic Science at the University of Tokyo.

Using spectroscopic techniques, scientists have already detected silicon-containing molecules in the gaseous clouds that envelop some stars and in the sparsely populated space between stars. In space, silicon is often found in dust grains containing stable compounds called silicates. However, highly reactive molecules, such as SiCN, have also been detected in the gas phase in the interstellar medium.

Searching for More Reactive Silicon Compounds

Endo and his colleagues wondered if compounds in the same family as SiCN, but with longer carbon chains, also existed in the interstellar medium. But there was big obstacle to answering the question: Researchers had not yet performed any laboratory experiments to determine the spectroscopic signatures of reactive, silicon and nitrogen-terminated carbon chain molecules.

To fill the knowledge gap, Endo and his team created molecules of SiC2N and SiC3N by mixing precursor gases in a supersonic jet and zapping the mixture with electric pulses. The researchers then measured the electromagnetic emissions of the molecules in a Fourier transform microwave spectrometer. To find the peaks in the emission spectrum, the researchers were guided by theoretical calculations.

"Our experiment now makes it possible to search for SiC2N and SiC3N in the interstellar medium," Endo said.

Space Chemistry Insights

Endo and his colleagues plan to use their new results to look for silicon and nitrogen-terminated carbon chain molecules in the gaseous cloud surrounding a giant infrared star called IRC+10216. Scientists had previously detected the single carbon SiCN surrounding this star.

"If [SiC2N and SiC3N] molecules are identified in astronomical objects and their abundances are determined, we will be able to obtain valuable information on the mechanisms for the formations of these molecules," Endo said. "In addition, the information may provide clues to understand formation pathways of other silicon-bearing molecules." The new information could give scientists clues about the chemical composition of the universe and the conditions that birth stars and planets.

Explore further: Mysterious molecules in space

More information: The article, "Laboratory detections of SiC2N and SiC3N by Fourier transform microwave spectroscopy" is authored by Hiroya Umeki, Masakazu Nakajima and Yasuki Endo. It will be published in The Journal of Chemical Physics on November 11, 2014. DOI: 10.1063/1.4900740

Related Stories

Mysterious molecules in space

July 29, 2014

Over the vast, empty reaches of interstellar space, countless small molecules tumble quietly though the cold vacuum. Forged in the fusion furnaces of ancient stars and ejected into space when those stars exploded, these lonely ...

Organic conundrum in Large Magellanic Cloud

June 23, 2014

( —A group of organic chemicals that are considered carcinogens and pollutants today on Earth, but are also thought to be the building blocks for the origins of life, may hold clues to how carbon-rich chemicals ...

All about dust

August 28, 2012

(—The space between stars is not empty—it contains copious amounts of gas and dust. Astronomers estimate that about 5-10% of the total mass of our Milky Way galaxy is contained in the interstellar gas and dust, ...

Interstellar dust and the sun

November 12, 2012

(—The space between stars is not empty. It contains copious but diffuse amounts of gas and dust; in fact about 5-10% of the total mass of our Milky Way galaxy is in interstellar gas. About 1% of the mass of this ...

NASA simulator successfully recreates space dust

May 7, 2014

( —A team of scientists at NASA's Ames Research Center in Moffett Field, Calif., has successfully reproduced, right here on Earth, the processes that occur in the atmosphere of a red giant star and lead to the ...

Recommended for you

Power stations driven by light

January 16, 2019

Green plants, algae and some bacteria use sunlight to convert energy. The pigments in chlorophyll absorb electromagnetic radiation, which induces chemical reactions in electrons. These reactions take place in the nucleus ...

Researchers report breakthrough in ice-repelling materials

January 15, 2019

Icy weather is blamed for multibillion dollar losses every year in the United States, including delays and damage related to air travel, infrastructure and power generation and transmission facilities. Finding effective, ...

The secret to Rembrandt's impasto unveiled

January 15, 2019

Impasto is thick paint laid on the canvas in an amount that makes it stand from the surface. The relief of impasto increases the perceptibility of the paint by increasing its light-reflecting textural properties. Scientists ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.