Photoelectron Circular Dichroism (PECD) is a forward‐backward asymmetry in the photoemission from a non‐racemic sample induced by circularly polarized light. PECD spectroscopy has potential analytical advantages for chiral discrimination over other chiroptical methods due to its increased sensitivity to the chiral potential of the molecule. The use of anions for PECD spectroscopy allows for mass‐selectivity and provides a path to simple experimental schemes that employ table‐top light sources. Evidence of PECD for anions is limited, and insight into the forces that govern PECD electron dynamics in photodetachment is absent. Here, we demonstrate a PECD effect in the photodetachment of mass‐selected deprotonated 1‐indanol anions. By utilizing velocity map imaging photoelectron spectroscopy with a tunable light source, we determine the energy‐resolved PECD over a wide range of photon energies. The observed PECD reaches up to 11 %, similar to what has been measured for neutral species.

The maximum magnetic field strength generated by Weibel-type plasma instabilities is estimated for typical conditions in the interstellar medium. The relevant kinetic dispersion relations are evaluated by conducting a parameter study both for Maxwellian and for suprathermal particle distributions showing that micro Gauss magnetic fields can be generated. It is shown that, depending on the streaming velocity and the plasma temperatures, either the longitudinal or a transverse instability will be dominant. In the presence of an ambient magnetic field, the filamentation instability is typically suppressed while the two-stream and the classic Weibel instability are retained.

Photoelektronen‐Zirkulardichroismus (im folgenden PECD, nach der englischen Bezeichnung) zeigt sich als eine Vorwärts‐Rückwärts‐Asymmetrie in der Photoemission nicht‐razemischer Proben, ausgelöst durch zirkular polarisiertes Licht. Gegenüber anderen chiroptischen Methoden hat die PECD‐Spektroskopie potentielle analytische Vorteile bei der Differenzierung chiraler Substanzen, da sie sehr sensitiv auf das chirale Potential von Molekülen ist. Anionen können für die PECD‐Spektroskopie entsprechend ihrer Masse selektiert werden und ihr Einsatz eröffnet Wege zu einfachen experimentellen Aufbauten, die auf handlichen (table‐top) Lasern basieren. Die Nachweise für den PECD von Anionen sind noch rar und das genaue Verständnis der Triebkräfte, welche die PECD‐Elektronendynamik im Photodetachment bestimmen, sind unklar. Hier zeigen wir den PECD‐Effekt im Photodetachment von massenselektierten, deprotonierten 1‐Indanol‐Anionen. Der PECD wird über einen großen Bereich von Photonenenergien mit einem Velocity‐Map‐Imaging(VMI)‐Photoelektronenspektrometer energieaufgelöst analysiert. Ein PECD von bis zu 11 % wird nachgewiesen, was vergleichbar mit gemessenen Werten für neutrale Moleküle ist.

Although gold has become a well-known nonconventional hydrogen bond acceptor, interactions with nonconventional hydrogen bond donors have been largely overlooked. In order to provide a better understanding of these interactions, two conventional hydrogen bonding molecules (3-hydroxytetrahydrofuran and alaninol) and two nonconventional hydrogen bonding molecules (fenchone and menthone) were selected to form gas-phase complexes with Au – . The Au – [M] complexes were investigated using anion photoelectron spectroscopy and density functional theory. Au – [fenchone], Au – [menthone], Au – [3-hydroxyTHF], and Au – [alaninol] were found to have vertical detachment energies of 2.71 ± 0.05, 2.76 ± 0.05, 3.01 ± 0.03, and 3.02 ± 0.03 eV, respectively, which agree well with theory. The photoelectron spectra of the complexes resemble the spectrum of Au – but are blueshifted due to the electron transfer from Au – to M. With density functional theory, natural bond orbital analysis, and atoms-in-molecules analysis, we were able to extend our comparison of conventional and nonconventional hydrogen bonding to include geometric and electronic similarities. In Au – [3-hydroxyTHF] and Au – [alaninol], the hydrogen bonding comprised of Au – ···HO as a strong, primary hydrogen bond, with secondary stabilization by weaker Au – ···HN or Au – ···HC hydrogen bonds. Interestingly, the Au – ···HC bonds in Au – [fenchone] and Au – [menthone] can be characterized as hydrogen bonds, despite their classification as nonconventional hydrogen bond donors.