Several series of bent-core mesogens derived from 3,5-diphenyl-1,2,4-oxadiazole with or without lateral groups and with different length terminal chains at both ends, and polycatenar molecules with three to six alkoxy chains are synthesized and their mesomorphic behaviour is investigated by polarizing microscopy, differential scanning calorimetry, X-ray diffraction (XRD), dielectric, electro-optical and second-harmonic generation (SHG) experiments. Most compounds exhibit broad regions of skewed cybotactic nematic (NcybC ) and tilted smectic (SmC) phases with a strong tilt of the aromatic cores (up to 63°), but non-tilted SmA and NcybA phases are also observed for a compound that has only one terminal chain. The XRD patterns of the nematic phases of most of the compounds investigated indicate a 2D periodicity with short correlation length in the magnetically aligned samples. This is of importance for the general interpretation of the small-angle XRD splitting patterns typically observed for aligned samples of bent-core nematic phases. In most nematic phases one current peak is observed in the half period of an applied electric field, though no coherent signal is found in the SHG experiments. Based on additional electro-optical and dielectric results, the nematic phases are considered to be cybotactic nematic phases with local polar order, and show a dielectric reorientation of the polar domains. Only chiral nematic phases (NcybC *), but not blue phases, are obtained for compounds with one or two chiral (3S)-3,7-dimethyloctyloxy tail(s).

We study the low-energy (E0 = 26 eV) electron-impact induced ionization and fragmentation of tetrahydrofuran using a reaction microscope. All three final-state charged particles, i.e., two outgoing electrons and one fragment ion, are detected in triple coincidence such that the momentum vectors and, consequently, the kinetic energies for charged reaction products are determined. The ionic fragments are clearly identified in the experiment with a mass resolution of 1 amu. The fragmentation pathways of tetrahydrofuran are investigated by measuring the ion kinetic energy spectra and the binding energy spectra where an energy resolution of 1.5 eV has been achieved using the recently developed photoemission electron source. Here, we will discuss the fragmentation reactions for the cations C4H8O(+), C4H7O(+), C2H3O(+), C3H6(+), C3H5(+), C3H3(+), CH3O(+), CHO(+), and C2H3(+).

The introduction of optical tweezers for trapping atoms has opened remarkable opportunities for manipulating few-body systems. Here, we present the first bottom-up assembly of atom triads. We directly observe atom loss through inelastic collisions at the single event level, overcoming the substantial challenge in many-atom experiments of distinguishing one-, two-, and three-particle processes. We measure a strong suppression of three-body loss, which is not fully explained by the presently availably theory for three-body processes. The suppression of losses could indicate the presence of local anti-correlations due to the interplay of attractive short range interactions and low dimensional confinement. Our methodology opens a promising pathway in experimental few-body dynamics.