The reactivity of slow electrons with molecules at different degrees of aggregation: gas phase, clusters and condensed phase

Ingólfsson, Oddur; Weik, F.; Illenberger, Eugen

doi:10.1016/s0168-1176(96)04392-3

Cited by 155 publications

(104 citation statements)

References 233 publications

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“…[3][4][5][6] By now, the fundamental rules of negative ion (NI) formation have been formulated. 7,8 There is no doubt that the symmetry conservation principle 7 plays a central role among them.…”

mentioning

confidence: 99%

Frozen shell approximation violation in negative ion formation from halogenated benzenes via dissociative attachment

Asfandiarov

Fokin

et al. 2000

Rapid Commun. Mass Spectrom.

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A series of benzene derivatives (R(1)C(6)H(4)R(2)) has been studied by means of electron capture negative ion mass spectrometry (ECNI-MS), and PM3 quantum chemical calculations. The dissociation channel M(-.) --> Hal(-) + (M - Hal). is analysed from the point of view of symmetry conservation. Generally, a symmetry ban on dissociation may be avoided in at least two ways: (i) out-of-plane vibrations of the halogen atom in the molecular negative ion (MNI), mixing pi- and sigma-states of the anion; (ii) symmetrical in-plane vibration of the C-Hal bond, changing the order of the empty levels in the MNI with subsequent radiationless conversion into a sigma-state. Our analysis shows that neither of them provides a satisfactory explanation of the ECNI mass spectra for chlorobenzene, if one retains the usual assumption that an additional electron goes into the LUMO of the neutral molecule. Thus, it may be concluded that in this case electron capture causes a significant perturbation of the energy ordering of vacant orbitals, thus making the frozen shell approximation inapplicable. Copyright 2000 John Wiley & Sons, Ltd.

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mentioning

confidence: 99%

Frozen shell approximation violation in negative ion formation from halogenated benzenes via dissociative attachment

Asfandiarov

Fokin

et al. 2000

Rapid Commun. Mass Spectrom.

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“…Руководствуясь полученными в газовой фазе экспе-риментальными данными, а также фактами, свиде-тельствующими о подобии процессов ДЗЭ в вакууме и конденсированном состоянии [18][19][20], рассмотрим гипотетические особенности захвата электронов мо-лекулами ресвератрола и пицеатаннола в сольватиро-ванном состоянии. Последний процесс будем считать моделью биохимических реакций вблизи дыхательной цепи митохондрий в условиях избыточного отрицатель-ного заряда.…”

Section: Discussionunclassified

“…Однако известно, что основные особенности ДЗЭ сохраняются при переходе от газовой фазы к конденсированному со-стоянию [18], в том числе, сечение ДЗЭ может возрастать на несколько порядков величины при внедрении моле-кулы-мишени в кластеры воды [19]. Процессы вблизи электрон-транспортной цепи митохондрий происходят на межфазных границах, т.е.…”

Section: Introductionunclassified

Resonance electron attachment to natural polyphenolic compounds and their biological activity

Pshenichnyuk¹,

Asfandiarov²,

Воробьев³

et al. 2015

LoM

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Resonance low-energy (0-14 eV) electron attachment to natural polyphenolic stilbenes possessing antioxidant properties, namely resveratrol and piceatannol, was investigated by means of dissociative electron attachment spectroscopy. Experimental findings were assigned on base of density functional theory (DFT) calculations of energies and symmetry of vacant molecular orbitals. It was found that characteristic decay of the molecular negative ions of compounds under investigation under gasphase conditions can be associated with elimination of neutral H 2 molecule and formation of quinone-like structure bearing excess electron. These fragment species can be responsible for ability of polyphenolic compounds to scavenge free radicals in the living cells. The gas-phase data were extrapolated to reactions in cellular environment by means of DFT calculations using polarizable continuum model approach. A molecular mechanism for antioxidant activity of polyphenolic compounds in proximity to the mitochondrial respiratory chain under conditions of excess negative charge was suggested. Namely, it is thought that molecular hydrogen, known for its selective antioxidant properties, can be efficiently generated via attachment of electrons ("leaked" from the respiratory chain into mitochondrial intermembrane space) to polyphenolic compound and may be responsible for its antioxidant activity. The corresponding negative fragment, i.e., quinone bearing an excess negative charge, can serve as electron carrier and can return the captured electron back to the respiration cycle. The number of hydroxyl substituents and their relative positions on aromatic rings of polyphenolic molecule are crucial for the present molecular mechanism, because these properties determine dissociative electron attachment cross-section.

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“…£ ÒÑÔÎÇAEÐËØ ÑÃÊÑÓÂØ AEÂÐ ÂÐÂÎËÊ àÍÔÒÇÓËÏÇÐÕÂÎßÐÞØ ÏÇÕÑAEÑÄ ËÔÔÎÇAEÑÄÂÐËâ ÒÓËÎËÒÂÐËâ àÎÇÍÕÓÑÐÑÄ Í ÅÂÊÑ-ÄÞÏ ÏÑÎÇÍÖÎÂÏ [9,10], Â ÕÂÍÉÇ Í ÍÎÂÔÕÇÓÂÏ Ë ÒÎÇÐÍÂÏ [9]. ¬ÓÑÏÇ ÕÑÅÑ, ÒÓÇAEÔÕÂÄÎÇÐÞ ÓÇÊÖÎßÕÂÕÞ àÕËØ ËÊÏÇÓÇ-ÐËÌ [9].°ÔÐÑÄÖ AEÂÐÐÑÅÑ ÑÃÊÑÓÂ ÔÑÔÕÂÄÎâáÕ ÕÇÑÓÇÕËÚÇ-ÔÍËÇ ÍÑÐÙÇÒÙËË ÒÓÑÙÇÔÔÂ, Ä ÓÂÏÍÂØ ÍÑÕÑÓÞØ ÂÐÂÎËÊË-ÓÖáÕÔâ ÓÇÊÖÎßÕÂÕÞ àÍÔÒÇÓËÏÇÐÕÑÄ.…”

Section: £äçAeçðëçunclassified

“…¬ÓÑÏÇ ÕÑÅÑ, ÒÓÇAEÔÕÂÄÎÇÐÞ ÓÇÊÖÎßÕÂÕÞ àÕËØ ËÊÏÇÓÇ-ÐËÌ [9].°ÔÐÑÄÖ AEÂÐÐÑÅÑ ÑÃÊÑÓÂ ÔÑÔÕÂÄÎâáÕ ÕÇÑÓÇÕËÚÇ-ÔÍËÇ ÍÑÐÙÇÒÙËË ÒÓÑÙÇÔÔÂ, Ä ÓÂÏÍÂØ ÍÑÕÑÓÞØ ÂÐÂÎËÊË-ÓÖáÕÔâ ÓÇÊÖÎßÕÂÕÞ àÍÔÒÇÓËÏÇÐÕÑÄ. ×ÇÓÇÐÙËâ âAEÇÓÐÞØ ÔÑÔÕÑâÐËÌ ÔÖÜÇÔÕÄÇÐÐÂ Ä ÑÃÓÂÊÑÄÂÐËË ÍÑÐÇÚÐÑÅÑ ÔÑÔÕÑâÐËâ.…”

Section: £äçAeçðëçunclassified

Electron attachment to free and bound molecules

Illenberger¹,

Smirnov²

1998

Успехи физических наук

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The reactivity of slow electrons with molecules at different degrees of aggregation: gas phase, clusters and condensed phase

Cited by 155 publications

References 233 publications

Frozen shell approximation violation in negative ion formation from halogenated benzenes via dissociative attachment

Frozen shell approximation violation in negative ion formation from halogenated benzenes via dissociative attachment

Resonance electron attachment to natural polyphenolic compounds and their biological activity

Electron attachment to free and bound molecules

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