Negative ions formation of the cytosine molecule by electron impact

Sukhoviya, M. I.; Shafranyosh, M. I.; Маргітич, М. О.; Shafranyosh, І. І.

doi:10.7124/bc.000711

Cited by 2 publications

(3 citation statements)

References 5 publications

(7 reference statements)

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“…Mass-spectrometric data obtained earlier by us [2] were used to determine the cross sections of the cytosine molecule dissociative ionization product yields. Cross sections of the positive-ion production for the most probable cytosine molecule fragments at 78 eV incident electron energy are shown in table 1.…”

Section: Positive Ionsmentioning

confidence: 99%

“…In this case genetic macromolecules are the basic target. It has been shown in our preliminary experiments carried out with the heterocyclic components of the above molecules [1][2][3][4] that under electron impact different physical processes occur: i.e., molecule excitation, ionization, dissociative excitation and dissociative ionization. The particles produced give an origin for a new cascade of physical and chemical reactions.…”

Section: Introductionmentioning

confidence: 99%

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Absolute cross sections of positive- and negative-ion production in electron collision with cytosine molecules

Shafranyosh

Sukhoviya

Shafranyosh

2006

J. Phys. B: At. Mol. Opt. Phys.

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Production of positive and negative ions of cytosine molecules (nucleic acid base) has been studied using a crossed electron and molecular beam technique. The method developed by the authors enabled the molecular beam intensity to be measured and the electron dependences and the absolute values of the total cross sections of production of both positive and negative cytosine ions to be determined. It has been shown that the total positive cytosine ion production cross section reaches its maximal value of 7.8 × 10−16 cm2 at the 78 eV electron energy. Dissociative ionization cross sections have also been determined. The maximum total negative cytosine ion production cross section was measured to be 4.2 × 10−18 cm2 at 1.5 eV.

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Section: Positive Ionsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Absolute cross sections of positive- and negative-ion production in electron collision with cytosine molecules

Shafranyosh

Sukhoviya

Shafranyosh

2006

J. Phys. B: At. Mol. Opt. Phys.

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“…Вивчено процес утворення негативних іонів молекулярних компонентів нуклеїнових кислот в інтервалі енергій електронів 0-12 еВ [14,[19][20][21][26][27][28][29][30]. У прямому експерименті визначено абсолютні величини та енергетичні залежності повних перерізів утворення негативних іонів молекул цитозину, тиміну, урацилу, аденіну та гуаніну.…”

Section: результати та обговоренняunclassified

Molecular mechanisms of influence of slow electrons on biological structures

2019

Biophysical Bulletin

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Background: The article reviews investigations carried out by biophysicists of the Transcarpathian Branch of the Ukrainian Biophysical Society, dedicated to the memory of the prominent Ukrainian biophysicist, Professor Yuri Pavlovich Blagoi. Objectives: Study of the peculiarities of physical processes and structural changes in nucleic acid molecules initiated by low-energy electrons (10-1-102 eV). Materials and methods: Molecular components of nucleic acids – nucleobases, nucleosides – were chosen as objects of research. A complex of methods is applied: the spectral method for obtaining the luminescence spectra of molecules excited by an electron impact; the electric method in determining the complete cross-sections of the formation of positive and negative ions; the method of gas-phase mass spectrometry with electron impact ionization. A new approach is proposed, which is based on the development of the methods for obtaining biomolecules in an isolated (gas) state, the formation of molecular beams, and the implementation of a crossed electron and molecular beams method. Results: The processes of excitation, ionization and fragmentation of molecules of nucleic acid bases under electron impact are investigated. The radiation spectra of biomolecules in the wavelength region from 200 nm to 500 nm for different energies of incident electrons are obtained. For identification of spectral bands, the excitation functions of biomolecules are investigated, mass spectrometry analysis of the bases is performed, semi-empirical quantum-chemical calculations of structural parameters are carried out. It is established that the complex superpositional nature of the spectra reflects the simultaneous occurrence of various physical processes, including, in addition to the direct excitation of the singlet and triplet states of the base molecules, the dissociation excitation and excitation of ionized biomolecules and their fragments. The analysis of the excitation functions shows the presence of intersystem transitions with the formation of triplet metastable states of the nucleic acid bases molecules. It is shown that the processes of the appearance of negative ions are of resonant nature and are accompanied by the dissociation of molecules even at energies smaller than the thresholds for excitation and ionization.

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Negative ions formation of the cytosine molecule by electron impact

Cited by 2 publications

References 5 publications

Absolute cross sections of positive- and negative-ion production in electron collision with cytosine molecules

Absolute cross sections of positive- and negative-ion production in electron collision with cytosine molecules

Molecular mechanisms of influence of slow electrons on biological structures

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