Chemists from Nagoya University in Japan have been surprised by their new creation: a hydrocarbon that absorbs near-infrared light at wavelengths of about 700 to 1,300 nanometers.

The absorption of the near-infrared range is not in itself unusual in organic chemistry, although it is also not particularly typical at wavelengths of 700 to 1000 nanometers.

Telling about the invention according to the press release however, those molecules that absorb near-infrared generally do not consist purely of carbon and hydrogen atoms. Hiroshi Shinokubon, Norihito Fukuin and Yuki Tanakan however, the new exceptional hydrocarbon created by. Near-infrared absorbing molecules generally have other atomic functional groups.

The new hydrocarbon has an aromatic structure and is slightly cup-shaped instead of planar. It can also be described as a slice of the C70 fullerene molecule, i.e., oval spherical carbon. The molecular formula of the molecule is C34H14 and is called as-indacenoterrylene, or more precisely as-indaseno[3,2,1,8,7,6-ghijklm]terrylene.

The structural formula and absorption spectrum of the molecule are shown in the diagram at the end of the news.

The lack of near-infrared absorption with both water and ordinary organic substances is illustrated in everyday life by the human body, which is quite translucent in the area of ​​deep red light and near-infrared in about 670 and 920 nanometers between.

The phenomenon can be seen not only by playing with a flashlight, but also by the blaze of the campfire and the sunshine. The infrared light emitted by the campfire and the Sun does not stop on the surface of the skin, but warms the body deeper.

Unlike near-infrared, in the medium and far-infrared range, absorptions of organic molecules are very common. From around 1300 to 1400 nanometers, significant absorption bands are found in as common organic substances as ethanol, methanol and table sugar; a milder peak with ethanol is already at 1,200 nanometers.

The above interface with fullerene is not explained asnear-infrared absorption of indacenoterrylene, as the fullerene molecule C70 does not have the same property. Instead, the special absorption is due to an exceptionally small difference as-indasenoterrylene electron orbitals.

Researchers scientific report has been published in Nature Communications and is free to read.

The story was originally published In Tekniikka & Talous magazine.