Themed collection Festschrift Ivan Powis: Advances in Molecular Photoelectron Spectroscopy: Fundamentals & Application

This themed collection includes a collection of articles on fundamentals and applications of molecular photoelectron spectroscopy.

In this perspective article, main trends of angle-resolved molecular photoelectron spectroscopy in the laboratory up to the molecular frame, in different regimes of light-matter interactions, are highlighted with emphasis on foundations and most recent applications.

In this perspective, we discuss the current state of the art of time-resolved photoelectron spectroscopy to probe nonadiabatic dynamics, including ab initio approaches for its simulation and new experimental efforts.

Onset, decay, and control of ultrafast quantum coherence in many-electron systems is in the focus of interest of attosecond physics. We discuss electronic and nuclear dynamics affecting it, and outline directions for future study.

This perspective article reviews specific challenges associated with photoemission spectroscopy of bulk liquid water, aqueous solutions, water droplets and water clusters.

Photoelectron spectroscopy has evolved into a powerful tool for physical chemistry and molecular physics. Some recent examples are highlighted in this perspective.

This article presents a new chirality detection method of structural isomers using nanosecond photoelectron circular dichroism (PECD).

The electronic and nuclear changes that take place before isomerisation sets in for the PYP chromophore anion are captured.

A threshold photoelectron spectrum of HBNH is reported, recorded using synchrotron radiation.

We investigated photoelectron circular dichroism (PECD) using pulses with various durations. From the experiment with fenchone, we found constancy of the PECD over a wide range of pulse durations and estimated lifetimes of internal conversions.

Charge–dipole interactions of the departing electron with the neutral residue affect the angular distribution in anion photodetachment.

Here, we report the coincident measurement of PICD and PECD effects in 1-phenylethylamine upon multiphoton ionization.

The photoionization dipole defines a molecule-specific vector field in the photoelectron momentum space. What information about this vector field is encoded in the photoelectron angular distribution obtained from a randomly oriented sample?

The photoelectron circular dichroism is strongly influenced by the origin where the electron is set free.

Synthetic chiral light enables ultrafast and highly efficient imaging and control of molecular chirality. Here we explore how this giant enantio-sensitivity could be exploited to monitor, in real time, chiral nuclear dynamics during chemical reactions.

Core-level photoelectron spectroscopy of molecules presents unique opportunities but also challenges in the Hard X-ray Spectroscopy (HAXPES) realm.

We use optimal control theory and quantum dynamical simulations to show that shaped electromagnetic pulses can increase the difference in absorption of the enantiomers of fenchone in an effective two-level description.

Conjugation and hyperconjugation in core-excited states of organosulfur molecules probed by a novel experimental and theoretical approach using resonant Auger spectroscopy.

The computation of Dyson orbitals and corresponding ionization energies has been implemented within the equation of motion coupled cluster singles, doubles and perturbative triples (EOM-CC3) method.

We present the first X-ray photoelectron circular dichroism (PECD) study from a liquid phase sample, exemplified for liquid fenchone at the C 1s edge.

Photoelectron angular distributions of ammonia reflect, under special circumstances, the double-well potential of its umbrella mode.

Photoionization of chiral molecules with two-color fields leads to photoelectron signals that are enantio-sensitive but nevertheless independent of the ellipticity of the field and thus robust with respect to changes of the two-color relative phase.

Elliptic dichroism parameter (from −1 (blue) to +1 (yellow)) in strong-field ionization of argon by an ω–2ω BEOTC (ε = 0.4 and 0.6) field.

2-D core-electron spectroscopy: resolving excitation and relaxation pathways.

In 2 + 1 fs-REMPI of chiral molecules, recording the forward–backward asymmetry in the photoelectron distribution as a function of the ionizing light ellipticity reveals the non-adiabatic couplings occurring during the 70 fs duration of the pulses.

The VUV photoionisation and photofragmentation of cyclo-alanine-alanine (cAA) has been studied in a joint experimental and theoretical work. The photoelectron spectrum and the photoelectronphotoion coincidence (PEPICO) measurements, which enable control of the energy being deposited, combined with quantum chemistry calculations, provide direct insight into the cAA molecular stability after photoionisation. The analysis of the ion-neutral coincidence experiments with the molecular dynamics simulations and the exploration of the potential energy surface allows a complete identification of the fragmentation pathways. It has been found that the fragmentation always start with the ring opening through the C–C bond cleavage, followed by release of neutral moieties CO or HNCO.

Vibrationally-resolved resonant Auger electron–photoion coincidence measurements allow observing the Auger–Doppler effect in ammonia following ultrafast dissociation. About 43% of the internal energy left in the system is transferred to vibrations.

A chiral initial state state is the sum of two counter-propagating chiral electron currents. Intense circularly polarized light selects the counter-rotating electrons and projects their asymptotic perpendicular velocity on the continuum to yield PECD.

Photoelectron circular dichroism (PECD) displays sensitivity to tiny conformational geometry modifications. The influence of rotating functional groups on PECD is confirmed through investigating norcamphor, a mono-conformer molecule.

Zero Kinetic Energy photoelectron spectroscopy has provided unique spectral and dynamic fingerprints of electronically excited states of UV filters used in nature, and allowed to characterize the hitherto elusive ground state of its radical cation.

The absolute photoionization cross section (PICS) of these crucial ketene intermediates supports their quantification in lignin pyrolysis, combustion and organic synthesis.

TPES spectroscopy is used to unveil the complex vibronic structure of 9-methyladenine cations.

Investigation of the fragmentation of doubly charged camphor molecule following C 1s Auger decay experimentally by VMI-PEPIPICO, supplemented with MD simulations.

In situ XPS of aerosol particles formed from aqueous and EtOH solutions of Mg and Na bromides show surface enrichment of Mg, while particles grown from aqueous solution of Ca and Mg chlorides do not exhibit surface segregation.

A new method is proposed to record photoelectron spectra based on the well-established pulsed-field-ionization zero-kinetic-energy photoelectron spectroscopy technique and inspired by the data treatment employed in slow photoelectron spectroscopy.

We have investigated the frontier orbitals of persistent organic radicals known as nitroxyls by resonant photoelectron spectroscopy (ResPES) under inner shell excitation.

VUV photoionization of gas-phase H₂SO₄ has been studied by using i²PEPICO. Three electronic states of H₂SO₄⁺ have been prepared and their ionization energies are determined, as well as the adiabatic appearance energy of fragments.

A combined experimental and theoretical study of the ortho-benzyne + acetylene reaction using iPEPICO spectroscopy concludes that phenylacetylene and benzocyclobutadiene are formed in a 2 : 1 ratio under nonequilibrium conditions.

Electron spectroscopy following Xe 3d and F 1s ionization in XeF₂ elucidates the influence of core electrons on molecular bonding.

Photoelectron photoion coincidence reveals two new dissociative ionization channels in the methanol dimer, including C–C bond formation, and establishes the H-scrambling mechanism by partial deuteration.

Anions cannot have Rydberg states, but anions with polar neutral cores can support highly diffuse dipole-bound states (DBSs) as a class of interesting electronic excited states below the electron detachment threshold.

Single photon double and triple ionization of allene is investigated using multi-particle coincidence spectroscopies. Key findings comprise supporting evidence for a previously proposed roaming mechanism in H₃⁺ formation by double ionization.

Ultrafast coherent oscillations and subsequent conformational dynamics in N-methyl piperidine are observed upon excitation to 3s and 3p Rydberg states.

The circular dichroism spectrum of protonated L-phenylalanyl-L-alanine near the S₀–S₁ origin band is strongly influenced by the side-chain conformation of the phenylalanine residue.

Mirror-image VUV photoelectron circular dichroism spectra (PECD) of the propeller-type chiral Ru(acac)₃ enantiomers were measured with asymmetries up to 14%, suggesting that PECD is a universal mechanism, inherent to any type of chirality.

C₂H₅O₂ plus its gauche and trans conformers are studied using synchrotron-based VUV photoionization mass spectrometry and theoretical calculations, and it is found that the gauche conformer has favorable Franck–Condon factors in photoionization.

Distant ligands invert photoelectron circular dichroism.