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171.
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Florian Schlütter Georges M. Pavlov Jean‐François Gohy Andreas Winter Andreas Wild Martin D. Hager Stephanie Hoeppener Ulrich S. Schubert 《Journal of polymer science. Part A, Polymer chemistry》2011,49(6):1396-1408
A series of RuII heterodinuclear complexes of ABA ‐type with electron‐deficient bis‐terpyridines as building blocks was synthesized by (R‐tpy)RuIIICl3 complexation. These compounds were characterized by NMR spectroscopy, MALDI‐TOF, ESI‐TOF mass spectrometry, and elemental analysis. The results were compared with a coil‐rod‐coil RuII metallo‐supramolecular copolymer, which was synthesized by bis‐complex formation between a hydrophilic ω‐terpyridine poly(ethylene glycol) RuII mono‐complex and a hydrophobic bis‐terpyridine‐functionalized rigid core. This amphiphilic RuII triblock copolymer showed self‐assembly to clusters and micelles in aqueous solution, which was studied by transmission electron microscopy and dynamic light scattering. Applying velocity sedimentation experiments the number of amphiphilic RuII ABA triblock copolymer molecules within the micelles could be estimated. Finally, the photophysical properties of the RuII supramolecular assemblies were investigated by UV–vis spectroscopy. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
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Die Anwendung radioaktiver Nuklide in der chemischen Industrie kann nach der jeweils verwendeten Eigenschaft des strahlenden Materials in drei Gruppen eingeordnet werden 相似文献
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A polyhedral active set algorithm PASA is developed for solving a nonlinear optimization problem whose feasible set is a polyhedron. Phase one of the algorithm is the gradient projection method, while phase two is any algorithm for solving a linearly constrained optimization problem. Rules are provided for branching between the two phases. Global convergence to a stationary point is established, while asymptotically PASA performs only phase two when either a nondegeneracy assumption holds, or the active constraints are linearly independent and a strong second-order sufficient optimality condition holds. 相似文献
178.
Gerhard Bringmann Dominik Hager Anu Schaumlöffel Matthias Groh Andreas Speicher 《Tetrahedron: Asymmetry》2013,24(9-10):575-581
Isoplagiochin C 1 was prepared for the first time in enantiopure form from synthetic racemic material, using a novel stereochemical concept. This macrocyclic bisbibenzyl contains two biaryl axes. Of these, axis A is configurationally stable by its fixation within the macrocyclic framework, while axis B is stereochemically unstable. By diesterification of rac-1 with enantiopure (P)-1,1′-binaphthyl-2,2′-dicarboxylic acid, axis B is locked in its P-configuration, thus allowing the resolution and separate saponification of dilactones (PA,PB,P)-3 and (MA,PB,P)-3 to give the pure enantiomers of 1. This concept permits recycling of any undesired enantiomer of 1 by thermal equilibration of the respective diastereomer of 3. 相似文献
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Tobias Janoschka Anke Teichler Andreas Krieg Martin D. Hager Ulrich S. Schubert 《Journal of polymer science. Part A, Polymer chemistry》2012,50(7):1394-1407
This work describes the polymerization of the free secondary amine bearing monomer 2,2,6,6‐tetramethylpiperidin‐4‐yl methacrylate (TMPMA) by means of different controlled radical polymerization techniques (ATRP, RAFT, NMP). In particular, reversible addition‐fragmentation chain transfer (RAFT) polymerization enabled a good control at high conversions and a polydispersity index below 1.3, thereby enabling the preparation of well‐defined polymers. Remarkably, the polymerization of the secondary amine bearing methacrylate monomer was not hindered by the presence of the free amine that commonly induces degradation of the RAFT reagent. Subsequent oxidation of the polymer yielded the polyradical poly(2,2,6,6‐tetramethylpiperidinyloxy‐4‐yl methacrylate), which represents a valuable material used in catalysis as well as for modern batteries. The obtained polymers having a molar mass (Mn) of 10,000–20,000 g/mol were used to fabricate well‐defined, radical‐bearing polymer films by inkjet‐ printing. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献