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The unique surface properties of grafted polydimethylsiloxane (PDMS) chains, particularly their omniphobicity and low friction, are influenced by molecular structure and tethering density. Despite molecularly smoothness and homogeneity, these surfaces exhibit significant variability in wettability and contact angle hysteresis (CAH). This work uncovers the molecular structure of grafted PDMS chains. Grafted PDMS chains synthesized using a difunctional chlorosilane initiator, which exhibits CAH <2° on silicon wafers, adopt a brush-to-mushroom conformation with a molecular weight ≈7,800 g mol -1 , a grafting density of 0.22 ± 0.4 chains nm -2 , and a thickness of ≈3 nm. Each PDMS chain terminates with a silanol group, and ≈96% of substrate silanols remain unreacted. The presence of these terminal silanols is confirmed with time-of-flight secondary ion mass spectroscopy, as is their removal when exchanged for trimethylsilyl groups, both on the substrate and terminating the PDMS chains. Quartz crystal microbalance with dissipation measurements show that this "capping" procedure exchanges ≈1.5 silanols nm -2 ; capping occurs at the substrate and PDMS chain end. The findings suggest that grafted, capped PDMS chains of this molecular weight are able to achieve excellent omniphobic properties even when the majority of surface silanols remain unreacted, which may aid in the design of future omniphobic materials., (© 2024 The Author(s). Small published by Wiley‐VCH GmbH.)

The integration of next-generation electronics into society is rapidly reshaping our daily interactions and lifestyles, revolutionizing communication and engagement with the world. Future electronics promise stimuli-responsive features and enhanced biocompatibility, such as skin-like health monitors and sensors embedded in food packaging, transforming healthcare and reducing food waste. Imparting degradability may reduce the adverse environmental impact of next-generation electronics and lead to opportunities for environmental and health monitoring. While advancements have been made in producing degradable materials for encapsulants, substrates, and dielectrics, the availability of degradable conducting and semiconducting materials remains restricted. π-Conjugated polymers are promising candidates for the development of degradable conductors or semiconductors due to the ability to tune their stimuli-responsiveness, biocompatibility, and mechanical durability. This perspective highlights three design considerations: the selection of π-conjugated monomers, synthetic coupling strategies, and degradation of π-conjugated polymers, for generating π-conjugated materials for degradable electronics. We describe the current challenges with monomeric design and present options to circumvent these issues by highlighting biobased π-conjugated compounds with known degradation pathways and stable monomers that allow for chemically recyclable polymers. Next, we present coupling strategies that are compatible for the synthesis of degradable π-conjugated polymers, including direct arylation polymerization and enzymatic polymerization. Lastly, we discuss various modes of depolymerization and characterization techniques to enhance our comprehension of potential degradation byproducts formed during polymer cleavage. Our perspective considers these three design parameters in parallel rather than independently while having a targeted application in mind to accelerate the discovery of next-generation high-performance π-conjugated polymers for degradable organic electronics.

Dye-dye conjugates have attracted significant interest for their utility in applications such as bioimaging, theranostics, and light-harvesting. Many classes of organic dyes have been employed in this regard; however, building blocks don't typically extend beyond small chromophores. This can lead to minor changes to the optoelectronic properties of the original dye. The exploration of dye-dye structures is impeded by long synthetic routes, incompatible synthetic conditions, or a mismatch of the desired properties. Here, we present the first-of-their-kind dye-dye conjugates of boron difluoride complexes of formazanate and dipyrromethene ligands. These conjugates exhibit dual photoluminescence bands that reach the near-infrared spectral region and implicate anti-Kasha processes. Cyclic voltammetry experiments revealed the generation of polyanionic species that can reversibly tolerate the uptake of up to 6 electrons. Ultimately, we demonstrate that BF 2 formazanates can serve as a synthetically accessible platform to build upon new classes of dye-dye conjugates., (© 2023 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)