Copolymers containing hydroxyl (i.e. vinyl alcohol, VA) or fluorine functionalities are synthetic macromolecules having prominent biomedical applications. The concentration of hydroxyl groups along the polymer chain controls the polymer polarity. Moreover, the introduction of perfluorinated organic moieties via the OH functionalities may lead to macromolecules having potential magnetic resonance imaging (MRI) active properties. The ring-opening metathesis polymerization (ROMP) reaction using welldefined ruthenium-catalyzed systems is one of the most promising synthetic tools to fabricate such polymers. Co-polymerization of norbornene grafted pyridino-18-crown-6 ether (7) with fluorine-functionalized norbornenes (10 and 11) results in polymers bearing host molecular moieties. It has been demonstrated that the complexation of these host copolymers with biogenic amines including dopamine hydrochloride (12) and L-alanyl-L-lysine dipeptide hydrochloride (13) is straightforward. Based on the 1 H NMR investigation of the 7 and 12 complexation, an equilibrium constant of log K = 4.3 ± 0.6 could be calculated. The in situ 1 H NMR investigations have revealed that the complex formation of 13 with monomer 7 and perfluorinated copolymer cp-7-10 takes place via both the lysine -NH 3 + and the alanine -NH 3 + moieties. However, in the case of homopolymer poly-7, the lysine-NH 3 + group coordination was observed exclusively. According to theoretical calculations, molecular switching of the crown ether structure of both the 7 monomer and its cp-7-10 copolymer were observed from 90 degrees bent to planar structure upon -NH 3 + ion coordination. † Electronic supplementary information (ESI) available. See
Amberlyst-15 supported cyclic alkyl amino carbene and bicyclic alkyl amino carbene ruthenium olefin metathesis catalysts for sustainable catalytic applications have been synthesized by the well-known wet impregnation method utilizing ionic complex/support interaction. Surface coverages are as high as 4 and 7 wt% were achieved in the case of the significantly higher pore volume Amberlyst-15, compared to Amberlyst-36. These phase separable catalysts show high activity in cross metathesis, ring closing metathesis and ethenolysis reactions compared to the reported heterogenized olefin metathesis catalysts. Leeching tests revealed no more than 1.5 ppm ruthenium content for the investigated metathesis reactions, which is well below the accepted 10 ppm limit in case of consumer products.
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