Synthesis, spectroscopic and electrochemical properties of new covalent assemblies between TTF and various acceptors

Five new acceptor-π–TTF-π-acceptor (A–D–A) triads that contain pyridine, quinoline, nitrophenyl or nitrofuryl groups as acceptor unit have been synthesized by two-fold Wittig olefination reactions and their electrochemical behavior has been studied by cyclic voltammetry (CV). The intramolecular charge transfer (ICT) band in these molecules was characterized by UV–visible electronic absorption spectroscopy and these studies were completed by DFT calculations in the gas phase. These materials appear to be good candidates for the preparation of electroactive discrete metal complexes or coordination polymers as well as for the preparation of radical cations salts

Influence of surface morphology on erosion of plasma-facing components in H-mode plasmas of ASDEX Upgrade

Net erosion of plasma-facing materials was investigated at the low-field-side (outer) strike-point area of the ASDEX Upgrade (AUG) divertor during H-mode discharges with small and frequent ELMs. To this end, Au and Mo marker samples with different surface morphologies and geometries were exposed to plasmas using the DIMII divertor manipulator. The results were compared to existing erosion and deposition patterns from various Land H-mode experiments, in the latter case the main difference was the size and frequency of the ELMs. We noticed that increasing surface roughness reduces net erosion but less than what is the case in L-mode. On the other hand, net-erosion rates in H-mode are generally 2–5 times higher than the corresponding L-mode values, in addition to which exposure in H-mode conditions results in strong local variations in the poloidal and toroidal erosion/deposition profiles. The latter observation we associate with the large migration length, on the order of several cm, of the eroded material, resulting in strong competition between erosion and re-deposition processes especially at poloidal distances > 50 mm from the strike point. Considerable net erosion was measured throughout the analysed poloidal region unlike in L-mode where the main erosion peak occurs in the vicinity of the strike point. We attribute this qualitative difference to the slow decay lengths of the plasma flux and electron temperature in the applied H-mode scenario. Both erosion and deposition require detailed analyses at the microscopic scale and the deposition patterns may be drastically different for heavy and light impurities. Generally, the rougher the surface the more material will accumulate on locally shadowed regions behind protruding surface features. However, rough surfaces also exhibit more non-uniformities in the quality or even integrity of marker coatings produced on them, thus complicating the analyses of the experimental data. We conclude that local plasma parameters have a huge impact on the PFC erosion rates and, besides incident plasma flux, surface morphology and its temporal evolution have to be taken into account for quantitative estimates of erosion rates and PFC lifetime under reactor-relevant conditions

Quantum chemical studies on molecular structure and reactivity descriptors of a series of trimethyltetrathiafulvalene functionalized by conjugated substituent.

International audienc

Molecular structure, hyperpolarizability, NBO and Fukui function analysis of a serie of 1,4,3,5-oxathiadiazepane-4,4-dioxides derived of proline

International audienc

Theoretical analysis and molecular orbital studies of a series of 1,4,3,5-oxathiadiazepane-4,4-dioxides derived of sarcosine

International audienc

Theoretical analysis and molecular orbital studies of a series of 1,4,3,5-oxathiadiazepane-4,4-dioxides derived of sarcosine

International audienc

Quantum chemical studies on molecular structure and reactivity descriptors of a series of trimethyltetrathiafulvalene functionalized by conjugated substituent.

International audienc

Density functional theory calculations and chemical reactivity of a series of dibenzylaminophenyl benzene-fused bis tetrathiafulvalenes

International audienc

Molecular structure, hyperpolarizability, NBO and Fukui function analysis of a serie of 1,4,3,5-oxathiadiazepane-4,4-dioxides derived of proline

International audienc