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51.
Sarah Crotty Felix H. Schacher Ulrich S. Schubert 《Journal of polymer science. Part A, Polymer chemistry》2012,50(23):4958-4965
We report the synthesis and characterization of well‐defined homo‐ and diblock copolymers containing poly(furfuryl glycidyl ether) (PFGE) via living anionic ring‐opening polymerization using different initiators. The obtained materials were characterized by SEC, MALDI‐TOF MS, and 1H NMR spectroscopy and molar masses of up to 9400 g/mol were obtained for PFGE homopolymers. If the amphiphilic diblock copolymer PEG‐block‐PFGE was dissolved in water, micelles with a PFGE core and a PEG corona were formed. Hereby, the hydrophobic PFGE core domains were used for the incorporation of a suitable bismaleimide and heating to 60 °C induced the crosslinking of the micellar core via Diels‐Alder chemistry. This process was further shown to be reversible. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
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Dr. Steffen Thies Hanno Sell Dr. Claudia Bornholdt Christian Schütt Dr. Felix Köhler Prof. Dr. Felix Tuczek Prof. Dr. Rainer Herges 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(51):16358-16368
The bistability of spin states (e.g., spin crossover) in bulk materials is well investigated and understood. We recently extended spin‐state switching to isolated molecules at room temperature (light‐driven coordination‐induced spin‐state switching, or LD‐CISSS). Whereas bistability and hysteresis in conventional spin‐crossover materials are caused by cooperative effects in the crystal lattice, spin switching in LD‐CISSS is achieved by reversibly changing the coordination number of a metal complex by means of a photochromic ligand that binds in one configuration but dissociates in the other form. We present mathematical proof that the maximum efficiency in property switching by such a photodissociable ligand (PDL) is only dependent on the ratio of the association constants of both configurations. Rational design by using DFT calculations was applied to develop a photoswitchable ligand with a high switching efficiency. The starting point was a nickel–porphyrin as the transition‐metal complex and 3‐phenylazopyridine as the photodissociable ligand. Calculations and experiments were performed in two iterative steps to find a substitution pattern at the phenylazopyridine ligand that provided optimum performance. Following this strategy, we synthesized an improved photodissociable ligand that binds to the Ni–porphyrin with an association constant that is 5.36 times higher in its trans form than in the cis form. The switching efficiency between the diamagnetic and paramagnetic state is efficient as well (72 % paramagnetic Ni–porphyrin after irradiation at 365 nm, 32 % paramagnetic species after irradiation at 440 nm). Potential applications arise from the fact that the LD‐CISSS approach for the first time allows reversible switching of the magnetic susceptibility of a homogeneous solution. Photoswitchable contrast agents for magnetic resonance imaging and light‐controlled magnetic levitation are conceivable applications. 相似文献
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Melanie Schmidlehner Felix Faschinger Lorenz Michael Reith Martin Ertl Wolfgang Schoefberger 《应用有机金属化学》2013,27(7):395-405
In this study, novel water‐soluble corrole amino acid conjugates were synthesized and characterized. The coupling reaction of A2B‐ and A3‐corroles with glycine ethyl ester and taurine under strong basic conditions proved to be successful and yielded di‐ and trifunctionalized corrole amino acid conjugates in good yields. The subsequent metalation of the corrole/amino acid conjugates broadens the scope for applications considerably. As examples, we herein show the catalytic activity of the Mn(III) A3‐corrole towards O2 evolution. First we employed tert‐butyl hydroperoxide (t‐BuOOH) as oxidant to obtain the Mn(V)oxo species and tetrabutyl ammonium hydroxide (TBAH) as hydroxide donor agent. Furthermore, the binding properties of the non‐metalated and the Mn(III) A3‐corrole/amino sulfonic acid conjugates and transport of proteins were investigated and the conjugates exhibited binding to human serum albumin (HSA). Finally, a novel Ga(III) A3‐corrole/amino sulfonic acid derivative was synthesized and we briefly describe the photophysical properties of this compound. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Afshin Nabiyan Johannes Bernhard Max Dr. Christof Neumann Magdalena Heiland Prof. Dr. Andrey Turchanin Prof. Dr. Carsten Streb Prof. Dr. Felix Helmut Schacher 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(68):16924-16929
An effective strategy to enhance the performance of inorganic semiconductors is moving towards organic-inorganic hybrid materials. Here, we report the design of core–shell hybrid materials based on a TiO2 core functionalized with a polyampholytic (poly(dehydroalanine)-graft-(n-propyl phosphonic acid acrylamide) shell (PDha-g-PAA@TiO2). The PDha-g-PAA shell facilitates the efficient immobilization of the photosensitizer Eosin Y (EY) and enables electronic interactions between EY and the TiO2 core. This resulted in high visible-light-driven H2 generation. The enhanced light-driven catalytic activity is attributed to the unique core–shell design with the graft copolymer acting as bridge and facilitating electron and proton transfer, thereby also preventing the degradation of EY. Further catalytic enhancement of PDha-g-PAA@TiO2 was possible by introducing [Mo3S13]2− cluster anions as hydrogen-evolution cocatalyst. This novel design approach is an example for a multi-component system in which reactivity can in future be independently tuned by selection of the desired molecular or polymeric species. 相似文献
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Analyse von Protease‐Inhibitor‐Interaktionen unter Nutzung evolvierbarer tricyclischer Microviridine
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Lukas M. Müller-Wirtz Daniel Kiefer Joschua Knauf Maximilian A. Floss Jonas Doneit Beate Wolf Felix Maurer Daniel I. Sessler Thomas Volk Sascha Kreuer Tobias Fink 《Molecules (Basel, Switzerland)》2021,26(9)
High inspired oxygen during mechanical ventilation may influence the exhalation of the previously proposed breath biomarkers pentanal and hexanal, and additionally induce systemic inflammation. We therefore investigated the effect of various concentrations of inspired oxygen on pentanal and hexanal exhalation and serum interleukin concentrations in 30 Sprague Dawley rats mechanically ventilated with 30, 60, or 93% inspired oxygen for 12 h. Pentanal exhalation did not differ as a function of inspired oxygen but increased by an average of 0.4 (95%CI: 0.3; 0.5) ppb per hour, with concentrations doubling from 3.8 (IQR: 2.8; 5.1) ppb at baseline to 7.3 (IQR: 5.0; 10.8) ppb after 12 h. Hexanal exhalation was slightly higher at 93% of inspired oxygen with an average difference of 0.09 (95%CI: 0.002; 0.172) ppb compared to 30%. Serum IL-6 did not differ by inspired oxygen, whereas IL-10 at 60% and 93% of inspired oxygen was greater than with 30%. Both interleukins increased over 12 h of mechanical ventilation at all oxygen concentrations. Mechanical ventilation at high inspired oxygen promotes pulmonary lipid peroxidation and systemic inflammation. However, the response of pentanal and hexanal exhalation varies, with pentanal increasing by mechanical ventilation, whereas hexanal increases by high inspired oxygen concentrations. 相似文献