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An approach to the development of fluorescent probes to follow polymerizations in situ using fluorinated cross-conjugated enediynes (Y-enynes) is reported. Different substitution patterns in the Y-enynes result in distinct solvatochromic behavior. β,β-Bis(phenylethynyl)pentafluorostyrene 7, which bears no donor substituents and only fluorine at the styrene moiety, shows no solvatochromism. Donor substituted β,β-bis(3,4,5-trimethoxyphenylethynyl) pentafluorostyrene 8 and β,β-bis(4-butyl-2,3,5,6-tetrafluorophenylethynyl)-3,4,5-trimethoxystyrene 9 exhibit solvatochromism upon change of solvent polarity. Y-enyne 8 showed the largest solvatochromic shift (94 nm bathochromic shift) upon changing solvent from cyclohexane to acetonitrile. A smaller solvatochromic response (44 nm bathochromic shift) was observed for 9. Lippert–Mataga treatment of 8 and 9 yields slopes of -10,800 and -6,400 cm -1, respectively. This corresponds to a change in dipole moment of 9.6 and 6.9 D, respectively. The solvatochromic behavior in 8 and 9 supports the formation of an intramolecular charge transfer (ICT) state. The low fluorescence quantum yields are caused by competitive double bond rotation. The fluorescence decay time of 9 decreases in methyltetrahydrofuran from 2.1 ns at 77 K to 0.11 ns at 200 K. Efficient single bond rotation in 9 was frozen at -50 °C in a configuration in which the trimethoxyphenyl ring is perpendicular to the fluorinated rings. 7–9 are photostable compounds. The X-ray structure of 7 shows it is not planar and that its conjugation is distorted. Y-enyne 7 stacks in the solid state showing coulombic, actetylene–arene, and fluorine–π interactions.
This introduction provides an overview of feminist approaches to International Relations. The authors compare the Anglo-American debate with the Germanspeaking discussion in order to reveal similarities and differences. They identify three particular areas of research that characterize the German-speaking feminist debate in International Relations: (1) works evolving out of peace studies; (2) research on globalization and international economic institutions; (3) studies focusing on women’s movements together with most current works centering around international norms. They argue that feminist approaches to norms constitute a particularly promising research area which provides new "tools" to account for international, regional or domestic policy-change. Gender-sensitive research on norms also allows to address ethical questions that are vital for feminist understandings of science. Moreover, this new focus on norms enables bridge-building between feminism and the mainstream.
On the occasion of his farewell lecture, Manfred Mols looks back to his academic work of the last four decades, and discusses the essential meaning of area studies. He tries to clarify the important denotation of institutes for regional researchers. Area studies should help us to understand changing processes in international policies and they do. He underlines his critical point of view with the position and treatment of area studies among certain universities in Germany.
This article is a reply to a statement by Elke Schwinger in WeltTrends 31. The author tries to strike the balance between "coming to terms with the past" and the role of criminal law in this process in Germany. The principle of prohibition of retroactive laws, fixed in the 1990 German Unification Treaty and in the Constitution, had been broken in the trials against the "Mauerschützen" (border guards) in German criminal courts since 1990. There is an artificially constructed past which does not correspond to the reality of the border regime before 1989. The author underlines that today the criminal law is misused for political aims within the German unification process.
"Small wars" will play an increasing role in the conflict scenarios of the 21st century, at the expense of inter-state wars. One of the key features of future war is the difficult differentiation between civilian and military targets, between combatants and noncombatants. It is argued that the parallel (and competing) structures of both states and non-state actors using force openly and equally will be a permanent feature of international security policy in the 21st century. This development is tantamount to the dissolution of the monopoly on the legitimate use of force by the states. The state-centered system of international relations has been a distinctive hallmark of the modern period. It is bound to give way, however, to the parallel and competing structures of state actors and non-state actors which was a central attribute of the Middle Ages. Jahresabo: 40,00 € (ermäßigt: 25,00 €)
Significant seasonal variation in size at settlement has been observed in newly settled larvae of Dreissena polymorpha in Lake Constance. Diet quality, which varies temporally and spatially in freshwater habitats, has been suggested as a significant factor influencing life history and development of freshwater invertebrates. Accordingly, experiments were conducted with field-collected larvae to test the hypothesis that diet quality can determine planktonic larval growth rates, size at settlement and subsequent post-metamorphic growth rates. Larvae were fed one of two diets or starved. One diet was composed of cyanobacterial cells which are deficient in polyunsaturated fatty acids (PUFAs), and the other was a mixed diet rich in PUFAs. Freshly metamorphosed animals from the starvation treatment had a carbon content per individual 70% lower than that of larvae fed the mixed diet. This apparent exhaustion of larval internal reserves resulted in a 50% reduction of the postmetamorphic growth rates. Growth was also reduced in animals previously fed the cyanobacterial diet. Hence, low food quantity or low food quality during the larval stage of D. polymorpha lead to irreversible effects for postmetamorphic animals, and is related to inferior competitive abilities.