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Molecular catalysts are attracting interest as drivers of redox reactions for sustainable applications. Through systematic molecular design, they could be engineered to have high selectivity and activity towards a multitude of catalytic reactions. However, as long as they are used in homogeneous setups, they will suffer from inconvenient energy supply, inefficient charge transport and difficulty in separation from reaction products. To be relevant for industrial applications, molecular catalysts must be bound to solid materials in direct contact with the energy source. In this regard, conducting polymers are particularly interesting, as they provide a straightforward means of both surface immobilization and charge transport. In this work, we synthesize and characterize three different metalloporphyrin-functionalized conducting polymers and apply them to catalysis of the hydrogen evolution reaction (HER) and the oxygen reduction reaction (ORR). We show that incorporation of porphyrins into conducting polymers is a reliable immobilization method, that the properties of both the porphyrin units and the polymer backbone are preserved in all systems, and that the polymers provide efficient charge transport to and from the catalytic centers. Nevertheless, we also find that the polymers are negatively affected by intermediates formed during the HER and the ORR. We conclude that the choice of immobilization method has a large impact on the quality of the molecular catalyst, and that the effect of the catalytic cycle on the immobilization matrix must be considered in the molecular design process.

Molecular catalysts are attracting interest as drivers of redox reactions for sustainable applications. Through systematic molecular design, they could be engineered to have high selectivity and activity towards a multitude of catalytic reactions. However, as long as they are used in homogeneous setups, they will suffer from inconvenient energy supply, inefficient charge transport and difficulty in separation from reaction products. To be relevant for industrial applications, molecular catalysts must be bound to solid materials in direct contact with the energy source. In this regard, conducting polymers are particularly interesting, as they provide a straightforward means of both surface immobilization and charge transport. In this work, we synthesize and characterize three different metalloporphyrin-functionalized conducting polymers and apply them to catalysis of the hydrogen evolution reaction (HER) and the oxygen reduction reaction (ORR). We show that incorporation of porphyrins into conducting polymers is a reliable immobilization method, that the properties of both the porphyrin units and the polymer backbone are preserved in all systems, and that the polymers provide efficient charge transport to and from the catalytic centers. Nevertheless, we also find that the polymers are negatively affected by intermediates formed during the HER and the ORR. We conclude that the choice of immobilization method has a large impact on the quality of the molecular catalyst, and that the effect of the catalytic cycle on the immobilization matrix must be considered in the molecular design process.

Research on lignin valorization has gained ground, driven by its potential to replace fossil-based phenolics in bio-based applications. Technical lignins are structurally complex and still poorly characterized, prompting the need for novel extraction processes for lignin of high analytical quality. In this context, a two-step cyclic extraction process for lignin was contrasted with a one-step cyclic extraction. The latter was shown to preserve the native structure of the spruce lignin product better and improved the yields of both the extracted lignin and residual fiber fraction. The application of the one-step cyclic extraction process to birchwood resulted in a similar protection of the lignin structure. Overall, a flexible physical protection (FPP) process for extraction of lignin with an abundance of native bonds is presented. The lignin product has a high abundance of ether bonds and hydroxyl functionalities, which are of interest in biochemical, polymer, and material applications., Not duplicate with diva2:1753851QC 20230830

The field of mechanically interlocked molecules (MIMs) has advanced rapidly in recent years, with much work focused on their use in materials, sensing, and catalysis. However, the use of MIMs in biology and biomedicine has been limited, despite the identifica-tion of naturally occurring MIMs in DNA and proteins and the poten-tial advantages of the mechanical bond in fields such as nanomedi-cine and tissue engineering. Difficulties in the synthesis of MIMs, along with their limited solubility and stability in biological media, have until recently impeded their wider application in biology. Contemporary advances have, however, enabled a broader integra-tion of the mechanical bond in biology; the mechanical interlocking endows these systems with unique functional advantages. Herein, we summarize recent advances in the application of small-molecule, biologically derived, and polymeric MIMs in biology, highlighting synergies ripe for future exploration., QC 20230722

Energy shortage and environmental pollution limit the sustainable development of human beings. Water, as a clean and renewable resource, provides a solution for sustainable energy conversion from water oxidation catalysis. Lessons should be learned from nature to explore efficient artificial catalysts. In this chapter, we will review recent major progress in natural photosynthesis, from the structure and functions to the mechanisms for the water-oxidizing center of the biological enzyme. Later, the development of molecular and material water oxidation catalysts is discussed, with a focus on the mechanisms and rational catalyst design., Part of ISBN 9780128231531QC 20230721

Inhibition of steroid sulfatase (STS) decreases estrogen production and thus, suppresses tumor proliferation. Inspired by irosustat, the first STS inhibitor in clinical trials, we explored twenty-one tricyclic and tetra-heterocyclic coumarin–based derivatives. Their STS enzyme kinetic parameters, docking models, and cytotoxicity toward breast cancer and normal cells were evaluated. Tricyclic derivative 9e and tetracyclic derivative 10c were the most promising irreversible inhibitors developed in this study, with KI of 0.05 and 0.4 nM, and kinact/KI ratios of 28.6 and 19.1 nM−1min−1 on human placenta STS, respectively., QC 20230524

Aryl diazonium salts are ubiquitous building blocks in chemistry, as they are useful radical precursors in organic synthesis as well as for the functionalization of solid materials. They can be reduced electrochemically or through a photo-induced electron transfer re- action. Here, we provide a detailed picture of the ground- and excited-state reactivity of a series of nine rare and earth-abundant photosensitizers with 13 aryl diazonium salts, which also included three macrocyclic calix[4]arene tetradiazonium salts. Nanosecond transient absorption spectroscopy confirmed the occurrence of excited-state electron transfer and was used to quantify cage- escape yields (i.e., the efficiency with which the formed radicals separate and escape the solvent cage). Cage-escape yields were large; they increased when the driving force for photo-induced elec- tron transfer increased and also tracked with the C–N2+ bond cleav- age propensity, among others. A photo-induced borylation reaction was then investigated with all the photosensitizers and proceeded with yields between 9% and 74%.

Efficient absorption is a highly important strategy to remove environmental pollutants (i.e., dyes and nano plastics), which relays on the development of innovative and sustainable absorbents. Herein, we designed an innovative aryl-based deep eutectic solvent (DES) using diphenylamine (DPA) and benzophenone (BZP) as the component at a molar ratio of 1:1, and this novel DES was denoted as DPA:BZP-1:1. The developed DPA:BZP-1:1 could efficiently adsorb RhB and PS nanoparticles from their aqueous solution/suspension, and the absorption efficiency could reach up to 97.3% and 80%, respectively. Notably, DPA:BZP-1:1 showed a higher absorption efficiency than commercial activated carbon. Experimental and computational results revealed that hydrogen bonding and 7C-7C stacking synergistically contributed to the excellent absorption ability of DPA:BZP-1:1 on dye Rhodamine B (RhB) and polystyrene (PS) nanoplastics. To the best our knowledge, this is the first study on efficient absorption of dye and nanoplastics by aryl-based DESs., QC 20230208