We report here the synthesis of polyureas from the dehydrogenative coupling of diamines and diformamides. The reaction is catalysed by a manganese pincer complex and releases H gas as the only by-product making the process atom-economic and sustainable. The reported method is greener in comparison to the current state-of-the-art production routes that involve diisocyanate and phosgene feedstock. We also report here the physical, morphological, and mechanical properties of synthesized polyureas. Based on our mechanistic studies, we suggest that the reaction proceeds isocyanate intermediates formed by the manganese catalysed dehydrogenation of formamides.
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http://dx.doi.org/10.1039/d3cy00284e | DOI Listing |
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January 2025
Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, Sendai, 980-8577, Japan.
Hollandite-type α-MnO exhibits exceptional promise in current industrial applications and in advancing next-generation green energy technologies, such as multivalent (Mg, Ca, and Zn) ion battery cathodes and aerobic oxidation catalysts. Considering the slow diffusion of multivalent cations within α-MnO tunnels and the catalytic activity at edge surfaces, ultrasmall α-MnO particles with a lower aspect ratio are expected to unlock the full potential. In this study, ultrasmall α-MnO (<10 nm) with a low aspect ratio (c/a ≈ 2) is synthesized using a newly developed alcohol solution process.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
This work introduces a novel Mn(I)-catalyzed enantioselective alkylation methodology that efficiently produces a wide array of P-chiral phosphines with outstanding yields and enantioselectivities. Notably, the exceptional reactivity of Mn(I) complexes in these reactions is demonstrated by their effective catalysis with both typically reactive alkyl iodides and bromides, as well as with less reactive alkyl chlorides. This approach broadens the accessibility to various P-chiral phosphines and simplifies the synthesis of chiral tridentate pincer phosphines to a concise 1-2 step process, contrary to conventional, labor-intensive multistep procedures.
View Article and Find Full Text PDFDalton Trans
January 2025
School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, Jiangsu, China.
Three new sodium manganese fluoro-pyrophosphate compounds, namely, NaMn(PO)F (I), NaMn(PO)F (II), and NaMn(PO)F (III), have been synthesized by heating a mixture of NaPF, NaPOF or NaHPO with different Mn sources in NaNO and KNO fluxes. The structures of the title compounds were characterized single-crystal X-ray diffraction (XRD). II is characteristic of a shell of Na ions that encloses one [Mn(PO)F] unit, whereas I and III reveal three-dimensional (3D) frameworks that consist of MnO, Mn/NaOF octahedra or MnO octahedra and distorted MnO square pyramids with PO units, where Na cations reside in different-membered ring one-dimensional (1D) tunnels.
View Article and Find Full Text PDFMolecules
December 2024
Alan G. MacDiarmid Institute, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, China.
Manganese dioxide (MnO) shows great potential in the field of electrochemical performance. But its poor conductivity, easy dissolution in electrolytes and undesirable ionic accessibility hinder its application. The construction of mesoporous polypyrrole/manganese dioxide (PPy/MnO) composites can effectively alleviate these problems.
View Article and Find Full Text PDFDalton Trans
January 2025
Department of Chemistry, Universitat de les Illes Balears, Crta de Valldemossa km 7.5, 07122 Palma de Mallorca, Baleares, Spain.
This perpective delves into the emerging field of matere bonds, a novel type of noncovalent interaction involving group 7 elements such as manganese, technetium, and rhenium. Matere bonds, a new member of the σ-hole family where metal atoms act as electron acceptors, have been shown experimentally and theoretically to play significant roles in the self-assembly and stabilization of supramolecular structures both in solid-state and solution-phase environments. This perspective article explores the physical nature of these interactions, emphasizing their directionality and structural influence in various supramolecular architectures.
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