The stereoselectivity of a Diels-Alder reaction within the periphery of hierarchically assembled titanium(IV) helicates formed from mixtures of achiral, reactive and chiral, unreactive ligands was investigated in detail. Following the pathway of the chiral induction, the chiral ligands, solvents as well as substituents at the dienophile were carefully varied. Based on the results of the stoichiometric reaction, a secondary amine-catalyzed nitro-Michael reaction is performed as well which afforded reasonable diastereoselectivities.
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http://dx.doi.org/10.3762/bjoc.16.195 | DOI Listing |
Molecules
January 2025
Department of Chemistry, University of Connecticut, Storrs, CT 06269, USA.
Optically responsive materials are applied in sensing, actuators, and optical devices. One such class of material is dye-doped liquid crystal polymers that self-assemble into cholesteric mesophases that reflect visible light. We report here the synthesis and characterization of a family of linear and mildly crosslinked terpolymers prepared by the ROMP of norbornene-based monomers.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Mechanical Engineering, National University of Singapore, Singapore, Singapore.
Biological materials, such as bamboo, are naturally optimized composites with exceptional mechanical properties. Inspired by such natural composites, traditional methods involve extracting nanofibers from natural sources and applying them in composite materials, which, however, often results in less ideal mechanical properties. To address this, this study develops a bottom-up nanofiber assembly strategy to create strong fiber-reinforced composite hydrogels inspired by the hierarchical assembly of bamboo.
View Article and Find Full Text PDFInorg Chem
January 2025
Industrial Research Institute of Nonwovens & Technical Textiles, Shandong Engineering Research Center for Specialty Nonwoven Materials, College of Textiles & Clothing, Qingdao University, Qingdao, Shandong 266071, P. R. China.
Promoting the rate of the oxygen reduction reaction (ORR) is critical for boosting the overall energy efficiency of the flexible zinc-air batteries (FZABs). Inspired by nature, we designed "branch-leaf" like hierarchical porous carbon nanofibers with ultralow loadings of Ir nanoparticles (NPs) derived from covalent-organic framework/metal-organic framework (COF/MOF) core-shell hybrids. The as-obtained Ir/FeZn-hierarchical porous carbon nanofibers (HPCNFs) showcase enhanced ORR performance, and the ultralow Ir loading reduces the cost while maintaining catalytic capacity.
View Article and Find Full Text PDFCarbohydr Polym
March 2025
Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084, PR China. Electronic address:
High-performance solar interface evaporators provide a promising, sustainable, and cost-effective solution to the global freshwater crisis through seawater purification. However, achieving a delicate balance between maximizing the evaporation rate and ensuring continuous, stable, and durable operation presents a critical challenge. Herein, we present a biomimetic cellulose/polypyrrole-coated silica/graphene evaporator with self-assembled nanofiber networks and vertically aligned vessels for enhanced salt resistance.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
National Energy Metal Resources and New Materials Key Laboratory, Engineering Research Center of the Ministry of Education for Advanced Battery Materials, Hunan Provincial Key Laboratory of Nonferrous Value-Added Metallurgy, School of Metallurgy and Environment, Central South University, Changsha 410083, P. R. China.
Rechargeable Zn-air batteries (RZABs) are poised for industrial application, yet they require low-cost, high-performance catalysts that efficiently facilitate both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). The pivotal challenge lies in designing multimetal active sites and optimizing the carbon skeleton structure to modulate catalyst activity. In this study, we introduce a novel hierarchical porous carbon-supported FeCoNi bifunctional catalyst, synthesized via a spray combustion method.
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