Aluminum amine-bis(phenolate) complexes for ring-opening polymerization of rac-lactide and ε-caprolactone

Five aluminum-based amine-bis(phenolate) complexes, three of them novel, with variation of the pendant donor arm were synthesized in excellent yields, and characterized by NMR spectroscopy and X-ray crystallography. The quantitative conversion of the aluminum alkyl species to the corresponding benzyl alkoxide was achieved by the addition of 1 mol eq. of benzyl alcohol, and was confirmed by 1H NMR spectroscopy. The aluminum alkoxides were excellent mediators for the ring-opening polymerization (ROP) of rac-lactide, yielding atactic poly(lactic acid), having excellent correlation between theoretical and calculated molecular weights accompanied by narrow molecular weight distributions. ROP of ε-caprolactone by the aluminum alkoxides showed modest control at 50°C in toluene, but much greater control was achieved when polymerizations were conducted at 25°C, with narrower molecular weight distributions observed in some cases. A relationship between the complex pendant donor arm and the resulting activity in the ROP of both rac-lactide and ε-caprolactone is discussed

Warum spielen wir Computerspiele? Von Counter Strike bis World of Warcraft: wie sich Identität in Online-Spielen konstituiert

Seit der Entstehung der ersten Computerspiele in den achtziger Jahren sind diese mittlerweile aus dem Alltag kaum mehr wegzudenken. Im Rahmen dieser Arbeit soll der Frage nachgegangen werden, wie sich Identitäten in Online-Spielen konstruieren. Hierfür wurden verschiedene Identitätskonzepte auf ihre Relevanz für Online-Spieler-Identitäten untersucht, es wurden sieben Leitfadeninterviews mit langjährigen Spielern von Online-Rollenspielen (MMORPGs), Strategiespielen (MOBAs) und Ego-Shootern durchgeführt und im Hinblick auf die Identitätskonstruktion ausgewertet

Bis(μ-diethyl­phosphido-κ2 P:P)bis­[bis(2,4,6-trimethyl­phen­yl)indium(III)]

The title compound, [In2(C9H11)4(C4H10P)2], contains a centrosymmetric In2P2 core with short inter­molecular In—P bonds. This core has acute P—In—P and obtuse In—P—In bond angles compared with other [R 2InPR′2]2 analogues, due to the presence of the bulky aromatic substituents on the In atom and the non-sterically demanding ethyl substituents on the P atom

(E)-3-Bromo-N-(1,3-oxazolidin-2-yl­idene)benzamide

The five- and six-membered rings in the title compound, C10H9BrN2O2, are essentially coplanar. This is consistent with a highly conjugated system, as seen in the short N—C bond distances of 1.308 (6) and 1.317 (5) Å