Functional cobalt-containing homo and block polymers are probed with respect to their redox-induced switchability and as preceramic materials.

A novel and feasible strategy for the preparation of functional polyhydrocarbosilane-based homo and block copolymers is described via a combination of anionic ring-opening polymerization of methylsilacyclobutane (MSB) and styrene followed by postmodification applying hydrosilylation protocols. Sterically demanding and functional vinyl compounds such as N-vinylcarbazole (NVC), vinylferrocene (VFc), and 9,10-di(1-naphthalenyl)-2-vinylanthracene (VADN) are block-selectively incorporated into the PMSB backbone with adjustable functional group contents between 26 mol% to 43 mol% with respect to the Si-H functionalities for the PMSB homopolymers and contents ranging from 28 mol% to 63 mol% for the corresponding diblock copolymers as evidenced by 1 H NMR spectroscopy. The novel functional diblock copolymers are capable of undergoing microphase separation as shown via TEM. † Electronic supplementary information (ESI) available: Additional data on PMSB homopolymers, 1 H NMR spectra, SEC, and DSC of all functional hydrosilylated PMSB homo-and block copolymers, 1 H NMR spectrum of NVC@PS-b-PMSB1 precipitated in methanol, cyclic voltammogram of VFc@PMSB1, TGA of VFc@PMSB1, and XRD pattern of ceramized VFc@PMSB. See

For the first time, the successful Gilch synthesis of poly(ortho-phenylene vinylenes) (ortho-PPVs) is reported. The molar mass of the constitutionally homogeneous ortho-PPVs reaches values as high as Mw ≈ 300 000 Da. The ortho-connectivity of the repeating units forces the chains to assume closely packed conformations even in good solvents. Significant perturbation of the π-electron systems and considerable shortening of the conjugation lengths are the consequences. UV-vis absorption and photoluminescence maxima consequently are shifted clearly toward shorter wavelengths compared to, e.g., classic para-PPVs.

Front Cover: Geometric squeezing of the poly(phenylene vinylene) repeating units from conventional para‐connectivity to the ortho isomeric state induces considerable perturbation of the delocalized π–electron system. Shortened conjugation lengths and significant blue‐shifts of UV‐vis absorption and photoluminescence characteristics are the consequences. Creative graphic support in catchy visualization of that squeezing effect provided by Mr. Christian Krupp, WKC project, is gratefully acknowledged. Further details can be found in the article by V. Rittscher, S. Kuch, and M. Rehahn* on page 814.