Passerini Multicomponent Reactions Enabling Self-Reporting Photosensitive Tetrazole Polymers.

We introduce the synthesis of photosensitive tetrazole monomers via Passerini multicomponent reactions (MCRs). We exploit the MCR's tolerance toward various functional groups under mild, catalyst-free conditions in a one-pot reaction setup to generate tetrazole-containing monomers featuring a methacrylic moiety, which enables their subsequent reversible addition-fragmentation chain transfer (RAFT) polymerization. By employing tetrazoles with either a 4-methoxy phenyl or a pyrene substituent, further modifications of the polymers in a wavelength-orthogonal, self-reporting fashion upon irradiation with either UV or visible light become possible.

Prevent or Cure-The Unprecedented Need for Self-Reporting Materials.

Self-reporting smart materials are highly relevant in modern soft matter materials science, as they allow for the autonomous detection of changes in synthetic polymers, materials, and composites. Despite critical advantages of such materials, for example, prolonged lifetime or prevention of disastrous material failures, they have gained much less attention than self-healing materials. However, as diagnosis is critical for any therapy, it is of the utmost importance to report the existence of system changes and their exact location to prevent them from spreading. Thus, we herein critically review the chemistry of self-reporting soft matter materials systems and highlight how current challenges and limitations may be overcome by successfully transferring self-reporting research concepts from the laboratory to the real world. Especially in the space of diagnostic self-reporting systems, the recent SARS-CoV-2 (COVID-19) pandemic indicates an urgent need for such concepts that may be able to detect the presence of viruses or bacteria on and within materials in a self-reporting fashion.

A Guanidine-Based Superbase as Efficient Chemiluminescence Booster.

We introduce the guanidine-based superbase 1,5,7-triaza-bicyclo-[4.4.0]dec-5-ene (TBD) as efficient enabler for chemiluminescence (CL) based on luminol in a simple, ready-to-use two component system. The strong CL is generated by the superbase's properties as peroxidase mimetic and bifunctional coreactant. The herein established concept allows for CL enabling molecules (superbases) to be readily implemented in larger molecular structures, including in polymers.

Polybutadiene Functionalization via an Efficient Avenue.

We introduce a facile and quantitative postpolymerization functionalization methodology for 1,4-polybutadienes, allowing us to decorate their pendent alkene functionalities with bromine and alkoxyether motifs carrying an array of functional groups ranging from tetrazoles to pyrenes. Specifically, the approach makes use of a mild, metal-free, electrophilic cascade reaction employing N-bromosuccinimide (NBS), a cyclic ether (i.e., THF), and a functional carboxylic acid. Detailed NMR, SEC, and ATR-IR studies confirm the successful modification.