Samara scientists discovered a new path for the synthesis of helical molecules — helicenes

Together with the colleagues from the USA universities, they discovered a new path for the synthesis of helical molecules – helicenes.

The international team of scientists has discovered a new way of synthesis of helicenes helical molecules- a unique class of polycyclic aromatic hydrocarbons (PAHs), which are precursors of biomolecules.

In the course of theoretical and experimental work of the scientists of Samara University, the University of Hawaii, Lawrence Berkeley National Laboratory and Florida International University, new properties and mechanisms for the formation of helicenes were studied. The results of the work are presented in the article “Gas Phase Synthesis of [4] – Helicene” published in Nature Communications journal. The methods of synthesis of helicenes helical molecules, existing in the scientific world, are complex and laborious because they involve a large number of intermediate steps. In the process of synthesis, molecules have to overcome high activation energy barriers, and it requires significant energy costs.

“We have proposed a new approach to the synthesis of helicenes using gas-phase chemistry methods, – said one of the authors of the article, the scientific supervisor of megagrant “Development of Physically Grounded Combustion Models” at Samara University, Professor at Florida International University Alexander Mebel. – Within the study, Samara University scientists discovered the mechanism of the reaction of the aromatic radical – phenanthrenyl (C14H9) with the C4H4 vinyl acetylene molecule, leading to the formation of the simplest helicene (C18H12). And our colleagues from Lawrence Berkeley National Laboratory confirmed the proposed mechanism by conducting a complex laboratory experiment using synchrotron radiation and a highly sensitive mass spectrometer.”

The results obtained in the course of the experiment will be in demand by the scientists who are investigating combustion reactions. The fact is that the compound [4] – helicene is formed during the combustion of hydrocarbons and is contained in the same exhaust of automobile engines. “On the Earth polycyclic aromatic hydrocarbons are harmful substances formed because of incomplete combustion of fuel, and are involved in the formation of soot that pollutes the environment, whereas in the interstellar space PAHs are precursors of biomolecules. Studying the structure and dynamics of the formation of twisted molecules of helicenes, we begin to better understand the mechanisms of formation of helical DNA molecules, which are an important part of the chemical evolution of the Universe. Therefore, the detailed understanding of the mechanisms for the formation of PAHs is important both for the development of environmentally friendly combustion technologies and for answering the question of the origin of life both in space and on the Earth”, – concluded the Professor of Florida International University.

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Helicenes are a class of polycyclic aromatic hydrocarbons (PAHs), in which the benzene building blocks are connected one after the other into a spiral chain. The attention of the scientific community is drawn to the study of the properties and structure of helicenes for two reasons: they are “building blocks” in the formation of more complex PAHs, and they also have unique properties associated with the presence of helical symmetry in helicene molecules.

Megagrant “Development of Physically Grounded Combustion Models” has been implemented within the Russian Federation governmental support for scientific research. International scientific laboratory “Physics and Chemistry of Combustion” under the guidance of Professor of Florida International University Alexander Mebel was established to implement the megagrant in the University. The project is aimed at solving the burning problem — prevention of environmental pollution. Within the megagrant, an experimental facility to study world-class combustion reactions is being created at Samara University.

The results of research conducted by the scientists of Samara University in close cooperation with both international and Russian research centres will contribute to the creation of more environmentally friendly and efficient combustion chambers for gas turbine engines.

The mechanism for the synthesis of PAHs proposed in the framework of this study by an international team of scientists is universal and can be used to explain the synthesis of higher order helicenes in various gas-phase hydrocarbon media. And the use of features of helicenes structure allows them to be used in various fields – organic and physical chemistry, materials science, nonlinear optics.

Nature Communications is a journal that publishes high-quality research from all areas of the Biological, Medical, Physical, Chemical, and Earth Sciences. According to the Scimago Journal Rank, the journal has the highest quartile Q1 in all scientific areas defined in the database: Biochemistry, Genetics and Molecular Biology, Chemistry, Physics and Astronomy. According to the Journal Citation Reports, in 2017, the impact factor was 12.353. In terms of citation levels, the journal has quartile Q1 in the field of Multidisciplinary Sciences.

Samara National Research University, being a multidisciplinary scientific and educational centre with a pronounced aerospace core, conducts current research on the socio-humanitarian, natural-science, economic, legal areas of personnel training and science. The university participates in the implementation of important projects of a national scale. Among them there is the first launch from the Vostochny Cosmodrome, when Samara rocket sent a fundamentally new Earth remote sensing device, the “AIST-2D” satellite (created by the scientists and students of Samara University in partnership with the JSC SRC “Progress” specialists) into orbit. The university is one of 21 participants of the “Project 5-100” – the Russian initiative of academic excellence, aimed at improving the competitiveness of the country’s leading universities at the world level. This is one of 29 higher educational institutions of Russia, having received the category of “National Research University”. Samara University is a participant of the project aiming at creation of one of 15 world-class scientific and educational centres on the territory of the Samara Region.