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Photoredox catalysis has recently emerged as a powerful synthesis tool in organic and polymer chemistry. In contrast to the great achievements realized in organic solvents, performing photocatalytic processes efficiently in aqueous media encounters several challenges. Here, it is presented how amphiphilic single‐chain polymeric nanoparticles (SCPNs) can be utilized as small reactors to conduct light‐driven chemical reactions in water. By incorporating a phenothiazine (PTH) catalyst into the polymeric scaffold, metal‐free reduction and C−C cross‐coupling reactions can be carried out upon exposure to UV light under ambient conditions. The versatility of this approach is underlined by a large substrate scope, tolerance towards oxygen, and excellent recyclability. This approach thereby contributes to a sustainable and green way of implementing photoredox catalysis., Photoredox catalysis takes a bath: Single‐chain polymeric nanoparticles are utilized as an efficient and recyclable platform to perform photoredox catalysis in water. The reduction of aryl halides and C−C cross coupling reactions are studied upon UV‐light illumination under ambient conditions.

Recent studies on water-splitting photoelectrochemical cells (PECs) have demonstrated the intriguing possibility of controlling the spin state in this chemical reaction to form H 2 and O 2 by exploiting the chirality of organic π-conjugated supramolecular polymers. Although this fascinating phenomenon has been disclosed, the chiral supramolecular materials reported thus far are not optimized for acting as efficient photosensitizer for dye-sensitized PECs. In this work we report on the design, synthesis, and characterization of chiral supramolecular aggregates based on C 3 -symmetric triphenylamine-based dyes that are able to both absorb visible light and control the spin state of the process. Variable temperature-dependent spectroscopic measurements reveal the assembly process of the dyes and confirm the formation of chiral aggregates, both in solution as well as on solid supports. Photoelectrochemical measurements on TiO 2 -based anodes validate the advantage of using chiral supramolecular aggregates as photosensitizer displaying higher photocurrent compared to achiral analogues. Moreover, fluorimetric tests for the quantification of the hydrogen peroxide produced, confirm the possibility of controlling the spin of the reaction exerting spin-selection with chiral supramolecular polymers. These results represent a further step towards the next-generation of organic-based water-splitting solar cells.

The self-assembly of alpha,alpha'-linked sexithiophenes with chiral and achiral penta(ethylene glycol) chains attached at the alpha-positions of the terminal rings, that is, 2,2':5',2'':5'',2''':5''',2'''':5'''',2'''''-sexithiophene-5,5'''''-dicarboxylic acid-2S)-2-methyl-3,6,9,12,15-pentaoxahexadecyl ester (1) and 2,2':5',2'':5'',2''':5'''',2''''':5''''',2'''''-sexithiophene-5,5'''''-dicarboxylic acid-3,6,9,12,15-pentaoxahexadecyl ester (2), respectively is described. Analysis of the UV/vis, fluorescence, circular dichroism, and circular polarization of luminescence spectroscopic data shows that these compounds form chiral aggregates in polar solvents and in the solid state. In n-butanol aggregation occurs at temperatures below 30 degrees C, while above this threshold temperature the aggregates break up without an intermediate disordered state of aggregation, and the compounds are molecularly dissolved. The "melting temperature" of the aggregates depends on the concentration of sexithiophene, indicating that the optical changes observed are a result of intermolecular processes. Mass spectrometric measurements reveal that 1 and 2 can form mixed aggregates. Analysis of the optical spectra reveals that in these mixed aggregates, chiral 1 molecules act as "sergeants" to direct the packing of the "soldiers" 2, illustrating cooperativity within the columns. In water, the same type of chiral aggregates are formed as in n-butanol below 30 degrees C; however, these aggregates are still present, but the chirality is lost above 30 degrees C. In spin-coated films of 1 chiral aggregates are present. AFM studies show that 1 self-organizes into chiral fiberlike structures in the solid state. Furthermore both 1 and 2 display thermotropic liquid crystalline behavior between 180 and 200 degrees C.

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The combination of enzymic polymn. with ATRP for the synthesis of branched (block) copolymers was investigated. Heterotelechelic polycaprolactone macroinimer was synthesized in a one-pot enzymic procedure by using 2-hydroxyethyl fN-bromoisobutyrate as a bifunctional initiator. A polymerizable end-group was introduced by subsequent in-situ enzymic acrylation with vinyl acrylate. The degree of end-group functionalization of the polycaprolactone macroinimer can be controlled by the water activity in the enzymic initiation step with the double headed initiator. The degrees of functionalization of the macroinimer with the ATRP initiator were between 83 and 97 %. In the acrylation step a functionalization of 80-90 % was achieved. Self condensing ATRP of the macroinimers was successfully conducted with and without the addn. of MMA as a comonomer as evident from the increase of mol. wt. upon ATRP.

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The interest in org. semiconducting materials for electronic materials applications is highlighted by the desire for easily processible materials that can be fabricated inexpensively on flexible substrates. Donor-acceptor org. materials are of particular interest for their applications in bipolar field effect transistors and solar cells. We have prepd. donor-acceptor materials based on oligothiophenes and perylenebisimides as our donor (p-type) and acceptor (n-type) blocks, resp. Alternating donor-acceptor block copolymers were prepd. via the Stille coupling of a thiophene-functionalized perylenebisimide with a bis(trimethylstannyl)-bithiophene initiator. Since a film morphol. consisting of strong donor-donor/acceptor-acceptor interactions is desired, we have focused our study on the effect of hydrogen bonding to reinforce the strong p-p stacking of \"like\" blocks of oligothiophenes and perylenebisimides. The synthesis of these materials, their surface characterization, photophys. measurements, as well as the performance of these materials in solar cells and bipolar field effect transistors will be presented.

Minimally invasive intervention strategies after myocardial infarction use state-of-the-art catheter systems that are able to combine mapping of the infarcted area with precise, local injection of drugs. To this end, catheter delivery of drugs that are not immediately pumped out of the heart is still challenging, and requires a carrier matrix that in the solution state can be injected through a long catheter, and instantaneously gelates at the site of injection. To address this unmet need, a pH-switchable supramolecular hydrogel is developed. The supramolecular hydrogel is switched into a liquid at pH > 8.5, with a viscosity low enough to enable passage through a 1-m long catheter while rapidly forming a hydrogel in contact with tissue. The hydrogel has self-healing properties taking care of adjustment to the injection site. Growth factors are delivered from the hydrogel thereby clearly showing a reduction of infarct scar in a pig myocardial infarction model.

We combined the chem. of dendrimers with the supermol. interactions of pseudorotaxane, resulting in poly(propyleneimine) dendrimers functionalized with dibenzo-24-crown-8 units at the periphery for binding secondary ammonium salts, a mol. recognition motif

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