Alle fünfe: Ein fünffach koordiniertes Siliciumzentrum mit fünf unterschiedlichen Ligandatomen (SiClSONC‐ und SiISONC‐Gerüste) wurde in Form des neutralen SiIV‐Komplexes 1 und des analogen Iodo‐Derivats erhalten. Beide Komplexe sind im Festkörper und in Lösung stabil. Der Chloroligand in 1 kann leicht ausgetauscht werden, sodass eine Reihe von fünffach koordinierten Siliciumkomplexen zugänglich sein sollte.

Alle fünfe: Ein fünffach koordiniertes Siliciumzentrum mit fünf unterschiedlichen Ligandatomen (SiClSONC‐ und SiISONC‐Gerüste) wurde in Form des neutralen SiIV‐Komplexes 1 und des analogen Iodo‐Derivats erhalten. Beide Komplexe sind im Festkörper und in Lösung stabil. Der Chloroligand in 1 kann leicht ausgetauscht werden, sodass eine Reihe von fünffach koordinierten Siliciumkomplexen zugänglich sein sollte.

The microencapsulation of alkaline salt hydrates suitable as inorganic phase change materials (PCMs) via surface Michael‐type addition polymerization of thiols and acrylates is reported. The encapsulation performance depending on the resins' acrylate‐to‐thiol ratio and monomer functionality is investigated, and the best encapsulation performance is found for resin compositions with considerable acrylate excess ratios. The step‐growth nature of the reaction can be substantiated via comparative bulk polymerizations. A multistage encapsulation mechanism is proposed in order to explain the different dependencies on the acrylate to thiol ratio observed in PCM encapsulations in comparison to bulk polymerizations.magnified image

The final result of a 2s Szy2 -2p Pzy2 Lamb-shift measurement by the laser resonance method in hydrogenic phosphorus is reported. Metastable 2s Sigz ions were prepared using a P 0.08 velocity beam of P + ions obtained from the MP tandem accelerator at the Centre de Recherches Nucleaires in Strasbourg. From the metastable state the transition to the 2p P3g2 state was induced with a high-power dye laser leading to a measured transition energy of AE' = 2.23133(12) eV. Subtracting the well-known fine-structure splitting AEFs = 2.31482(2) eV, the Lamb shift is deduced to be E,"~t(LS) = 20 188 (29) GHz. This result is compared with the theoretical value Eth, ,(LS) = 20 254(10) GHz and with other experimental results for the Lamb shift in the region Z & 18. Finally, the utility of the Lamb-shift measurements in testing the G(Zcx) function of the self-energy, which includes only terms in (Zn)", n ) 6, is discussed. PACS number(s): 12.20.Fv, 32.70.3z, 32.30.r, 31.30.Jv

Experimental stoichiometric gelation boundaries of a set of branched thiol to acrylate Michael addition polymerization systems were investigated, and the observed limits were compared to theoretical critical molar ratio (CMR) intervals. These CMR intervals were calculated via the Flory–Stockmayer equation (for the upper limit) and via a formula derived from the Carothers equation (for the lower limit). The method provides a simple procedure to verify the existence of a step-growth mechanism in cross-linked polymerizations, and it is also applicable to monomers with functionality distributions. It is shown that the investigated Michael addition systems have gelation boundary values which are consistent with a predominant step-growth mechanism.