Three-body deprotonation fragmentation dynamics of C6H63+ induced by electron-impact ionization.

The three-body fragmentation dynamics of benzene trications C6H63+ induced by 200 eV electron-impact produced by a photoemission cathode is investigated. All three fragment ions are detected in coincidence, and their momentum vectors are determined by employing a COLTRIMS reaction microscope. The detailed kinematical information of three deprotonation fragmentation channels of H+ + C3H2+ + C3H3+, H+ + C2H3+ + C4H2+, and H+ + C2H2+ + C4H3+ are obtained.

Revealing the Role of N Heteroatoms in Noncovalent Aromatic Interactions by Ultrafast Intermolecular Coulombic Decay.

Despite the widely recognized importance of noncovalent interactions involving aromatic rings in many fields, our understanding of the underlying forces and structural patterns, especially the impact of heteroaromaticity, is still incomplete. Here, we investigate the relaxation processes that follow inner-valence ionization in a range of molecular dimers involving various combinations of benzene, pyridine, and pyrimidine, which initiate an ultrafast intermolecular Coulombic decay process. Multiparticle coincidence momentum spectroscopy, combined with calculations, enables us to explore the principal orientations of these fundamental dimers and, thus, to elucidate the influence of N heteroatoms on the relative preference of the aromatic π-stacking, H-bonding, and CH-π interactions and their dependence on the number of nitrogen atoms in the rings.

Directly imaging excited state-resolved transient structures of water induced by valence and inner-shell ionisation.

Real-time imaging of transient structure of the electronic excited state is fundamentally critical to understand and control ultrafast molecular dynamics. The ejection of electrons from the inner-shell and valence level can lead to the population of different excited states, which trigger manifold ultrafast relaxation processes, however, the accurate imaging of such electronic state-dependent structural evolutions is still lacking. Here, by developing the laser-induced electron recollision-assisted Coulomb explosion imaging approach and molecular dynamics simulations, snapshots of the vibrational wave-packets of the excited (A) and ground states (X) of DO are captured simultaneously with sub-10 picometre and few-femtosecond precision.

Intermolecular Charge Transfer Induced Fragmentation of Formic Acid Dimers.

We investigate the intermolecular nonradiative charge transfer process in a double hydrogen-bonded formic acid (FA) dimer, initiated by electron-collision induced double ionization of one FA molecule. Through fragment ions and electron coincident momentum measurements and ab initio calculations, we obtain direct evidence that electron transfer from the neighboring FA molecule to fill one of the two vacancies occurs by a potential energy curve crossing of FA^{++}+FA with FA^{+}+FA^{+*} curves, forming an electronic excited state of dicationic dimers. This process causes the breaking of two hydrogen bonds and subsequently the cleavage of C─H and C─O covalent bonds in the dimers, which is expected to be a general phenomenon occurring in molecular complexes and can have important implications for radiation damage to biological matter.

Structural and dynamical studies of CH-bonded CH-CHdimer by ultrafast intermolecular Coulombic decay.

The inner-valence ionization and fragmentation dynamics of CH-CHdimer induced by 200 eV electron impact is studied utilizing a multi-particle coincidence momentum spectroscopy. The three-dimensional momentum vectors and kinetic energy release (KER) of the CH+CHion pairs are obtained by coincident momentum measurement. Our analysis on the absolute cross sections indicates that the intermediate dication CH-CHis preferentially produced by the removal of an inner-valence electron from CHor CHand subsequent relaxation of ultrafast intermolecular Coulombic decay followed by two-body Coulomb explosion.

Ultrafast Charge and Proton Transfer in Doubly Ionized Ammonia Dimers.

We investigate the ultrafast energy and charge transfer processes between ammonia molecules following ionization reactions initiated by electron impact. Exploring ionization-induced processes in molecular clusters provides us with a detailed insight into the dynamics using experiments in the energy domain. We ionize the ammonia dimer with 200 eV electrons and apply the fragment ions coincident momentum spectroscopy and nonadiabatic molecular dynamics simulations.

Triple ionization and fragmentation of benzene trimers following ultrafast intermolecular Coulombic decay.

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

Concerted Double Hydrogen-Bond Breaking by Intermolecular Coulombic Decay in the Formic Acid Dimer.

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

Clinical analysis of endometrial cancer patients with obesity, diabetes, and hypertension.

The purpose of our study was to study the postoperation outcome and incidence of deep vein thrombosis (DVT) in endometrial cancer (EC) patients with or without hypertension, diabetes, and obesity. This analysis included 219 patients with endometrial carcinoma who were treated between 2002 and 2012 at the Department of Obstetrics and Gynecology, Yangzhou University Hospital. Patients were divided into five groups based on the comorbidities.