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Radiation-induced transformations of isolated CH3CN molecules in noble gas matrices
Radiation Physics and Chemistry. 2017. No. 141. P. 363–368.
Kameneva S., Volosatova A. D., Feldman V. I.
The transformations of isolated CH3CN molecules in various solid noble-gas matrices (Ne, Ar, Kr, and Xe) under the action of X-ray irradiation at 5 K were investigated by FTIR spectroscopy. The main products are CH3NC, CH2CNH and CH2NCH molecular isomers as well as CH2CN and CH2NC radicals. The matrix has a strong effect on the distribution of reaction channels. In particular, the highest relative yield of keteneimine (CH2CNH) was found in Ne matrix, whereas the formation of CH3NC predominates in xenon. It was explained by differences in the matrix ionization energy (IE) resulting in different distributions of hot ionic reactions. The reactions of neutral excited states are mainly involved in Xe matrix with low IE, while the isomerization of the primary acetonitrile positive ions may be quite effective in Ne and Ar. Annealing of the irradiated samples results in mobilization of trapped hydrogen atoms followed by their reactions with radicals to yield parent molecule and its isomers. The scheme of the radiation-induced processes and its implications for the acetonitrile chemistry in cosmic ices are discussed.
Stepan V. Portnov, Shuvaev A., Melnikov I. et al., Organic Letters 2025 Vol. 27 No. 34 P. 9522–9526
Fused nitrogen heterocycles emerged recently as promising scaffolds for the design of small-molecule energetic materials. Herein, we present the synthetic route to a series of new furazano[3,4-e][1,2,4]triazolo[4,3-a]pyrazines demonstrating outstanding thermal stability (the decomposition onset above 300 °C) and low mechanical sensitivity. Moreover, a favorable combination of high crystal densities (1.68−1.84 g cm−3) and high enthalpies of ...
Added: September 11, 2025
Migulin A. V., MIlyutin C V, Lichitsky B. V. et al., Organic and Biomolecular Chemistry 2025 Vol. 23 No. 17 P. 4172–4185
In the present communication, a comprehensive study of the photochemical behavior of terarylenes with a 2-aminothiazole bridge unit and an allomaltol substituent was performed. It was shown that for the considered substrates, two types of photoprocesses can be realized. By controlling the structure of the starting material, the photoprocess can be directed toward the 6π-electrocyclization ...
Added: September 10, 2025
Zasimov P., Ryazantsev S. V., Tyurin D. et al., Monthly Notices of the Royal Astronomical Society 2021 Vol. 506 No. 3 P. 3499–3510
In this work, we have examined the radiation-induced synthetic chemistry occurring in an astrochemically important C2H2–CO system at the molecular level using a matrix isolation approach. The 1:1 C2H2···CO intermolecular complex of linear structure was obtained in the solid low-temperature (5 K) noble gas matrices by deposition of the C2H2/CO/Ng (Ng = Ar, Kr, Xe) gaseous mixtures and ...
Added: November 16, 2021
Telegina L., Strelkova T., Ezernitskaya M. et al., Journal of Organometallic Chemistry 2020 Vol. 926 Article 121465
A series of 3-cymantrenylalkylisothioureas (2) was synthesized. DFT calculations showed that
compounds 2 in solutions are dimers. The photolysis of 2 was studied by IR, UV-vis and NMR spectroscopic
methods. Irradiation of compounds 2 results in the formation of two type chelates, in which the manganese atom is
coordinated to the S (3) or N (4) atoms of ...
Added: March 6, 2021
Фельдман В. И., Рязанцев С. В., Каменева С. В., Russian Chemical Reviews 2021 Vol. 90 P. 1145–1165
Recent progress in observational astronomy and astrophysics has stimulated the intensive laboratory studies aimed at elucidation of the mechanisms of evolution of molecular matter in interstellar space and various space objects. One of the most intriguing and rapidly developing areas of these studies is the so-called "cold astrochemistry" devoted to the complex processes occurring in ...
Added: February 28, 2021
Zasimov P., Ryazantsev S. V., Tyurin D. et al., Monthly Notices of the Royal Astronomical Society 2020 Vol. 491 No. 4 P. 5140–5150
Investigations of the low-temperature radiation-induced transformations in the C2H2–H2O system are relevant to the chemistry occurring in interstellar and cometary ices. In this work, we applied a matrix isolation technique to study the radiation-driven evolution of this system at molecular level in order to get new mechanistic insight. The 1:1 C2H2⋅ ⋅ ⋅H2O complexes were prepared in ...
Added: January 21, 2021
Glebov E., Bakulina O. D., Shushakov A. A. et al., Mendeleev Communications 2020 Vol. 30 No. 3 P. 322–324
The photophysical and photochemial properties of dipyrido[3,2-a:2′,3′-c]phenazine (dppz) in acetonitrile have been investigated by laser flash photolysis and ultrafast pump-probe spectroscopy. The excitation of dppz to the first singlet excited state was followed by vibrational cooling with solvent relaxation for ∼3 ps and then intersystem crossing for ∼50 ps. Spectral and kinetic characteristics of the triplet excited ...
Added: January 18, 2021
Glebov E., Pozdnyakov I., Semionova V. V. et al., Mendeleev Communications 2020 Vol. 30 No. 1 P. 61–63
Early processes in photochemistry of 2,3-bis(2,5-dimethylthiophen-3-yl)cyclopent-2-enone were explored using the ultrafast pump-probe spectroscopy. The photocyclization occurs from the antiparallel conformation of an open form on a time scale of 7 ps, while the parallel conformation exhibits an intersystem crossing within 130 ps. The mechanism and timescales were revealed as typical of other thiophene-containing diarylethenes. ...
Added: January 18, 2021
Shushakov A. A., Matveeva S. G., Pozdnyakov I. et al., Photochemical and Photobiological Sciences 2020 Vol. 19 P. 1222–1229
It is known that trans,cis,cis-[RuCl2(DMSO)2(H2O)2] (1a) complexes, which are formed upon dissolution of trans-[RuCl2(DMSO)4] in water, demonstrate light-induced cytotoxicity. The mechanistic study of 1a photochemistry has been performed using ultrafast pump–probe spectroscopy, laser flash photolysis and stationary photolysis. The first stage of 1a photochemistry is the photoexchange of a DMSO ligand to a water molecule; its quantum yield is wavelength-dependent (estimating ...
Added: January 18, 2021
Glebov E., Matveeva S. G., Pozdnyakov I. et al., Photochemical and Photobiological Sciences 2020 Vol. 19 P. 1569–1579
The photochemistry of the OsIVCl62− complex in ethanol was studied by means of stationary photolysis, nanosecond laser flash photolysis, ultrafast pump–probe spectroscopy and quantum chemistry. The direction of the photochemical process was found to be wavelength-dependent. Irradiation in the region of the d–d and LMCT bands results in the photosolvation (with the wavelength-dependent quantum yield) and ...
Added: January 18, 2021
Каменева С. В., Kobzarenko A. V., Feldman V. I., Radiation Physics and Chemistry 2015 No. 110 P. 17–23
The processes occurring in the X-irradiated C2H2/Kr and HCl/Kr systems in the temperature range of 7–30 K were studied using a combination of FTIR and EPR spectroscopy. In both cases, irradiation results in effective decomposition of isolated molecules (C2H2 or HCl) and production of trapped H atoms. The thermal decay of trapped atoms in solid krypton was ...
Added: November 20, 2019
Каменева С. В., Tyurin D. A., Feldman V. I., Radiation Physics and Chemistry 2016 No. 124 P. 30–37
In this work we report the results of systematic studies on the radiation-induced transformations in HCN/Ng systems (Ng=Ne, Ar, Kr or Xe) at 7 K using a combination of FTIR and EPR spectroscopy. It was shown that HCN underwent efficient decomposition producing H atoms, CN radicals and HNC isomer. The thermally induced reactions of H atoms ...
Added: November 20, 2019
Каменева С. В., Ryazantsev S. V., Saenko E. V. et al., Radiation Physics and Chemistry 2016 Vol. 124 P. 7–13
The radiation-induced transformations of small molecules at low temperatures play an important role in the interstellar, planetary and atmospheric chemistry. This work presents a review of our recent model studies on the radiation chemistry of relevant molecules in solid noble gas (Ng) matrices, including some preliminary new results. Among the triatomic molecules, water and carbon ...
Added: November 20, 2019
Kameneva S., Tyurin D. A., Feldman V. I. et al., Journal of Chemical Physics 2016 No. 145 P. 214309
Spectroscopic characteristics and X-ray induced transformations of the HCN⋯⋯CO2 complex in solid Ar and Kr matrices were studied by FTIR spectroscopy and ab initio calculations at the CCSD(T) level. The complex was prepared by deposition of the HCN/CO2/Ng gas mixtures (Ng = Ar or Kr). The comparison of the experiment and calculations prove formation of a linear, H-bonded NCH⋯⋯OCO complex with a substantial red ...
Added: November 20, 2019
Kameneva S.V., Tyurin D. A., Feldman V. I., Physical Chemistry Chemical Physics 2017 No. 19 P. 24348–24356
The HCN⋯CO complex and its X-ray induced transformation to HNC⋯CO in solid noble gas (Ng) matrices (Ng = Ne, Ar, Kr, Xe) was first characterized by matrix isolation FTIR spectroscopy at 5 K. The HCN⋯CO complex was obtained by deposition of HCN/CO/Ng gaseous mixtures. The assignment was based on extensive quantum chemical calculations at the ...
Added: November 20, 2019
Kameneva S.V., Volosatova A. D., Feldman V. I., Physical Chemistry Chemical Physics 2019 No. 24 P. 13014–13021
Acetonitrile and the species resulting from its dehydrogenation play an important role in the radiation-induced evolution of organic matter in the space environment. In this work, we report on FTIR spectroscopic studies of the degradation of isolated CH3CN and CD3CN molecules induced by prolonged X-ray irradiation in solid noble gas matrices at 5 K. The ...
Added: November 20, 2019
Pozdnyakov I., Melnikov A. A., Šípoš R. et al., Chemical Physics Letters 2016 Vol. 660 P. 209–213
Transient absorption spectroscopy is used to study photophysical processes of 1:1 Fe(III) complexes with all four fluorosalicylic acid isomers (Fe-FSAs) in aqueous solutions. Excited states of Fe-FSAs decay to the ground electronic state with two time constants. The faster process is interpreted as internal conversion to the vibrationally hot electronic ground state and the slower ...
Added: October 31, 2018