Till Rittner

The synthesis of differently substituted polyferrocenylmethylenes (PFM) via ring‐opening transmetalation polymerization (ROTP) is reported. A number of novel, symmetrically and asymmetrically substituted carba[1]magnesocenophanes have been prepared, which were used as precursors and allowed investigations of the influence of different substitution patterns on the PFM polymer properties. The novel carba[1]magnesocenophanes have been fully characterized by ¹ H and ¹³ C{ ¹ H} NMR spectroscopy, and structurally authenticated by single‐crystal X‐ray diffraction (SC‐XRD). The corresponding PFMs were obtained with molecular weights in a range of M _w =1900 g mol ⁻¹ up to 15100 g mol ⁻¹ and corresponding dispersities of Đ =1.48 to 1.81. All PFMs have been fully characterized by ¹ H and ¹³ C{ ¹ H} NMR spectroscopy, as well as by gel permeation chromatography (GPC), thermal gravimetric analysis (TGA) and matrix assisted laser desorption ionization‐time‐of‐flight (MALDI‐ToF) mass spectrometry. Pyrolysis of spyrocyclic substituted PFM resulted in a ceramic yield above 50 %, while the obtained residue was characterized by powder X‐ray diffraction (PXRD).

Porous metallopolymer membranes are prepared via the self-assembly and non-solvent-induced phase separation (SNIPS) process. These membranes efficiently remove (transition)metal ions and perfluorinated organic substances from the water phase.

Porous organic cobaltocenium‐containing particles are scarce in literature but highly interesting for their electrochemical properties and reusability in, for example, catalysis or magnetic systems. In this work, we present a scalable one‐pot strategy to introduce tailorable amounts of cobaltocenium on a porous substrate, adjusting the electrochemical switching capability. For this purpose, 3‐(triethoxysilyl)propan‐1‐amine (APTES) and ethynyl cobaltocenium hexafluorophosphate is used as functionalization agents for in‐situ catalyst‐free hydroamination, followed by silane condensation at the particles’ surface. Functionalized particles are characterized by attenuated total reflection infrared spectroscopy (ATR‐IR), thermogravimetric analysis (TGA), laser scanning confocal microscopy (LSCM), scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDS), inductively coupled plasma mass spectrometry (ICP‐MS), powder X‐ray diffraction (PXRD) and cyclic voltammetry (CV) showing excellent control over the degree of functionalization, i. e., the added cobaltocenium reagents. The electrochemical stability and good addressability while preserving the porous structure are shown. By utilizing higher amounts of APTES, the overall cobaltocenium amount can be reduced in favor of additional amine groups, strongly affecting the electrochemical behavior, making this functionalization strategy a good platform for metallopolymer immobilization and tailored functionalization. Additionally, thermal treatment of the synthesized metallopolymer microparticles paves the way to magnetic properties with tailorable microporous architectures for end‐of‐life and upcycling aspects.

Cobaltocenium-containing polymers, an emerging class of materials, have historically been challenging to prepare due to their chemical robustness. In this work, we introduce a novel and highly efficient method for their preparation based on methacrylate-containing block copolymers (BCPs), allowing segment-selective introduction of functional moieties. The catalyst-free and quantitative hydroamination reaction we introduce has proven successful for the post-modification of amine-containing polymers with cobaltocenium. To demonstrate the versatility of this method, we successfully synthesized a series of BCPs consisting of polystyrene and a 5 to 20 wt% poly(tert-butyl aminoethyl methacrylate) (PtBAEMA) segment by living anionic polymerization. The selective functionalization with ethynyl-cobaltocenium hexafluorophosphate results in adjustable 5 to 40 wt% cobaltocenium units in the polymer as part of the PtBAEMA block segment. The success was monitored by IR spectroscopy, and the quantitative incorporation of the cobaltocenium moiety was verified by ¹H NMR, UV-Vis spectroscopy, and TGA. DSC proved the block-selective cobaltocenium introduction by an additional glass transition temperature at 154 °C, and the strong microphase separation character of the amphiphilic BCPs leads to lamellar structures in the bulk state, as proven by TEM investigations. Finally, the water contact angle on polymer films is compared, showing polarity inversion and tunability upon conversion of hydrophilic amine to hydrophobic cobaltocenium hexafluorophosphate moieties. This successful synthesis and characterization of cobaltocenium-containing BCPs not only paves the way for a new class of metallopolymers but also offers functionalization possibilities for a variety of other responsive moieties, providing access to functional BCPs.

The synthesis of a water-soluble polycobaltoceniumylmethylene chloride (PCM-Cl) via ring-opening transmetalation polymerization is presented. Starting from a carba[1]magnesocenophane and cobalt(II) chloride, this route gives access to a polymer with methylene-bridged cobaltocenium moieties within the polymers' main-chain. The polymer was characterized by NMR spectroscopy, elemental analysis, TGA, DSC, XRD, and CV measurements, as well as UV-vis spectroscopy. Furthermore, GPC measurements in an aqueous eluent versus pullulan standards were conducted to gain insight into the obtained molar masses and distributions. In addition, the ion-dependent solubility was demonstrated by anion exchange, tuning the hydrophobic/hydrophilic properties of this redox-responsive material.