Despite the widely recognized importance of noncovalent interactions involving aromatic rings in many fields, our understanding underlying forces and structural patterns, especially impact heteroaromaticity, is still incomplete. Here, we investigate relaxation processes that follow inner-valence ionization a range molecular dimers various combinations benzene, pyridine, pyrimidine, which initiate an ultrafast intermolecular Coulombic decay process. Multiparticle coincidence momentum...

Abstract Intermolecular interactions involving aromatic rings are ubiquitous in biochemistry and they govern the properties of many organic materials. Nevertheless, our understanding structures dynamics clusters remains incomplete, particular for systems beyond dimers, despite their high presence macromolecular such as DNA proteins. Here, we study fragmentation benzene trimer that represents a prototype higher-order clusters. The trimers initially ionized by electron-collision with creation...

We report experimental studies of electron-impact ionization nitrogen (${\mathrm{N}}_{2}$) and oxygen (${\mathrm{O}}_{2}$) molecules using a cold target recoil ion momentum spectrometer (COLTRIMS, reaction microscope). The is detected in coincidence with one outgoing electron such that the vectors consequently kinetic energies for these final-state particles are determined. cross sections producing doubly singly charged parent ions were measured as function incident energy ranging from 50 to...

The fragmentation dynamics of dicationic dimers acetylene molecules initiated upon strong-field laser ionization is studied. Time-resolved pump-probe experiments with femtosecond pulses, accompanied by ab initio dynamical calculations, allow us to evaluate the detailed behavior molecular ions during dissociation process. properties intermediate C2H2+⋯C2H2+ state created pump pulse are probed a second which causes further ionization. time-dependent yield coincident C2H2+ + C2H22+ ion pair...

We investigate the intermolecular nonradiative charge transfer process in a double hydrogen-bonded formic acid (FA) dimer, initiated by electron-collision induced ionization of one FA molecule. Through fragment ions and electron coincident momentum measurements ab initio calculations, we obtain direct evidence that from neighboring molecule to fill two vacancies occurs potential energy curve crossing FA^{++}+FA with FA^{+}+FA^{+*} curves, forming an electronic excited state dicationic...

Hydrogen bonds are ubiquitous in nature and of fundamental importance to the chemical physical properties molecular systems condensed phase. Nevertheless, our understanding structural dynamical hydrogen-bonded complexes particular electronic excited states remains very incomplete. Here, by using formic acid (FA) dimer as a prototype DNA base pair, we investigate ultrafast decay process initiated removal an electron from inner-valence shell molecule upon electron-beam irradiation. Through...

We report the fragmentation dynamics of double ionization tetrahydrofuran (THF) induced by electron impact (${E}_{0}=200$ eV). Using a multiparticle coincidence momentum spectrometer, hydrogen molecule (${\mathrm{H}}_{2}$) production channel, i.e., and ${\mathrm{THF}}^{++}\ensuremath{\rightarrow}{\mathrm{H}}_{2}+{\mathrm{C}}_{3}{\mathrm{H}}_{5}{}^{+}+{\mathrm{CHO}}^{+}$, is observed identified using an ion-ion map correlated projectile energy-loss spectrum. The measured kinetic energy...

The three-body fragmentation dynamics of benzene trications C6H63+ induced by 200 eV electron-impact produced a photoemission cathode is investigated. All three fragment ions are detected in coincidence, and their momentum vectors determined employing COLTRIMS reaction microscope. detailed kinematical information deprotonation channels H+ + C3H2+ C3H3+, C2H3+ C4H2+, C2H2+ C4H3+ obtained. By analyzing the energy correlation spectra among all ions, we find that primarily generated sequential...

An experimental procedure is reported, which provides the absolute triple differential cross sections (ATDCSs) for electron-impact ionization of large (bio)molecules. This type measurements represents most stringent tests new or existing theoretical models. We will use this to test accuracy best currently available models problems (65 eV) molecules water $({\mathrm{H}}_{2}\mathrm{O})$, tetrahydrofuran $({\mathrm{C}}_{4}{\mathrm{H}}_{8}\mathrm{O})$, and their hydrogen-bonded dimer...

We investigate the ultrafast energy and charge transfer processes between ammonia molecules following ionization reactions initiated by electron impact. Exploring ionization-induced in molecular clusters provides us with a detailed insight into dynamics using experiments domain. ionize dimer 200 eV electrons apply fragment ions coincident momentum spectroscopy nonadiabatic simulations. identify two mechanisms leading to doubly charged dimer. In first one, single molecule is ionized. This...

Imaging the charge distributions and structures of molecules clusters will promote understanding dynamics quantum system. Here, we report a method by using an Ar atom as tip to probe benzene (Bz) cations in gas phase. Remarkably, measured Bz + ( δ H = 0.204, C −0.037) 2+ 0.248, 0.0853) agree well with calculated Mulliken distributions, 2 is reconstructed distributions. The two isomers (T-shaped PD isomers) can be resolved from inter-molecular potential V R ) between ions, dimer theoretical...

The fragmentation of two isomers C3H4, propyne (CH3CCH) and allene (CH2CCH2), is investigated by 50 keV/u Ne8+ impact. Obvious isomer effects are observed comparing the time-of-flight spectra generated from isomers. Six two-body channels C3H4 2+ dications identified for each isomer. CH2 + C2H2 found to be most favored CC bond breaking channel both isomers, indicating that CH3CCH2+ intends rearrange structure containing group before fragmentation. For CH channels, it CH3CCH which contains a...

The fragmentation dynamics of triply charged benzene [(${\mathrm{C}}_{6}{\mathrm{H}}_{6}{)}^{3+}$] induced by 260 eV electron-impact ionization are investigated using a multiparticle coincidence momentum spectrometer. By measuring three fragment ions and one outgoing electron in quadruple coincidence, we identify the complete three-body dissociation channels ${{\mathrm{CH}}_{2}}^{+} + {\mathrm{C}}_{2}{{\mathrm{H}}_{3}}^{+} {\mathrm{C}}_{3}{\mathrm{H}}^{+}, {{\mathrm{CH}}_{3}}^{+}...

This paper reports the structure and intermolecular potential energy curve (PEC) of heteroaromatic thiophene dimers obtained using a cold-target recoil-ion momentum spectroscopy reaction microscope. The three-dimensional momenta kinetic release (KER) ${\mathrm{C}}_{4}{\mathrm{H}}_{4}{\mathrm{S}}^{+}+{\mathrm{C}}_{4}{\mathrm{H}}_{4}{\mathrm{S}}^{+}$ ion pairs are by coincident measurement. two-body dissociation channel is initiated either rapid removal one outer-valence electron from each...

The ionization and fragmentation of small water clusters induced by electron impact (80 eV) is investigated. Using a multiparticle coincidence spectrometer (reaction microscope), all three charged final state particles—two outgoing electrons one fragment ion—are detected. Nonprotonated <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:msubsup><a:mrow><a:mo>(</a:mo><a:msub><a:mi mathvariant="normal">H</a:mi><a:mn>2</a:mn></a:msub><a:mi...

We report a combined experimental and theoretical study on the fragmentation dynamics following ultrafast intermolecular Coulombic decay (ICD) in ${({\mathrm{H}}_{2}\mathrm{O})}_{6}$ water clusters upon electron impact ionization. By coincident fragment ions momentum spectroscopy, we show that ICD can be initiated by inner-valence ionization of molecule. Our ab initio molecular simulations is followed proton transfer leading to formation...

We report a combined experimental and theoretical study of the ionization dynamics tetrahydrofuran induced by 250 eV electron impact in which highest occupied molecular orbital is ionized leading to stable parent ion. Experimentally reaction microscope was used, covering nearly entire $4\ensuremath{\pi}$ solid angle for ejected slow electron. present triple-differential cross sections projectile scattering angles ${\ensuremath{\theta}}_{1}$ = $\ensuremath{-}{10}^{\ensuremath{\circ}}$ as...

The single ionization and dissociation of ethanol molecules induced by low-energy electrons ( E 0 = 90 eV) are investigated using multiparticle coincident momentum spectroscopy. By detecting two outgoing e 1 2 ) one fragment ion in coincidence, we obtain the energy deposition − during electron molecule, i.e., binding spectra, for production different ionic fragments C H 5 OH + , 4 COH 3 O . These data allow us to study channels products. In particular, focus on as a product double hydrogen...

The inner-valence ionization and fragmentation dynamics of CH4-C6H6dimer induced by 200 eV electron impact is studied utilizing a multi-particle coincidence momentum spectroscopy. three-dimensional vectors kinetic energy release (KER) the CH4++C6H6+ion pairs are obtained coincident measurement. Our analysis on absolute cross sections indicates that intermediate dication CH4+-C6H6+is preferentially produced removal an from CH4or C6H6and subsequent relaxation ultrafast intermolecular Coulombic...

Synopsis Fragmentation dynamics of two isomers C 3 H 4 , propyne (CH CCH) and allene 2 CCH ), is in-vestigated by 50 keV/u Ne 8+ impact. Isomerization processes are identified in two-body fragmentation channels 2+ for both isomers. Besides, we observe new dissociation 3+ trications, + . For CH the peak shoulder structures kinetic energy release spectrum channel attributed to different geometries products comparing with theoretical cal-culation.

Ionization of the $3p$ orbital argon (Ar) monomers, dimers (${\mathrm{Ar}}_{2}$), and small-size Ar clusters (${\mathrm{Ar}}_{n},\phantom{\rule{0.16em}{0ex}}\ensuremath{\langle}n\ensuremath{\rangle}\ensuremath{\approx}15$) is investigated for 90-eV electron impact. Experimentally, three-dimensional momentum vectors two outgoing electrons residual ion are measured in triple coincidence, as mass-over-charge ratio ion, using a reaction microscope that covers large part final-state phase space....