Supramolecular polymers based on benzene-1,3,5-tricarboxamides (BTAs) functionalized with an L- or D-proline moiety display high catalytic activity towards aldol reactions in water. High turnover frequencies (TOF) of up to 27×10(-4) s(-1) and excellent stereoselectivities (up to 96% de, up to 99% ee) were observed. In addition, the catalyst could be reused and remained active at catalyst loadings and substrate concentrations as low as 0.1 mol % and 50 mM, respectively. A temperature-induced conformational change in the supramolecular polymer triggers the high activity of the catalyst. The supramolecular polymer's helical sense in combination with the configuration of the proline (L- or D-) is responsible for the observed selectivity.
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http://dx.doi.org/10.1002/chem.201405410 | DOI Listing |
Angew Chem Int Ed Engl
January 2025
Universidad Complutense de Madrid Facultad de Ciencias Quimicas, Inorganic Chemistry Department, 28034, Madrid, SPAIN.
Achieving high battery performance from low-cost, easily synthesisable electrode materials is crucial for advancing energy storage technologies. Metal organic frameworks (MOFs) combining inexpensive transition metals and organic ligands are promising candidates for high-capacity cathodes. Iron-chloranilate-water frameworks are herein reported to be produced in aqueous media under mild conditions.
View Article and Find Full Text PDFSci Total Environ
January 2025
Department of Chemical Engineering, Tennessee Technological University, Cookeville, TN, United States. Electronic address:
The overall objective of the present work was to quantify how shear, coupled with varying salt concentration, affected the particle size distribution and relaxation/aggregation behavior for various organic sources of nonliving natural organic matter (NNOM) in surface water. NNOM has been implicated as a conditioning agent leading to the formation of biofilms such as algae. NNOM is also a responsible in surface waters for facilitated transport of a variety of anthropogenic pollutants.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, 1098 XH Amsterdam, Netherlands.
We present the synthesis, structural analysis, and remarkable reactivity of the first carbon nanohoop that fully incorporates ferrocene in the macrocyclic backbone. The high strain imposed on the ferrocene by the curved nanohoop structure enables unprecedented photochemical reactivity of this otherwise photochemically inert metallocene complex. Visible light activation triggers a ring-opening of the nanohoop structure, fully dissociating the Fe-cyclopentadienyl bonds in the presence of 1,10-phenanthroline.
View Article and Find Full Text PDFDalton Trans
January 2025
Department of Chemistry, Graduate School of Natural Science and Technology, Shimane University, 1060, Nishikawatsu, Matsue, Shimane, 690-8504, Japan.
Paddlewheel-type diruthenium(II,II) complexes are paramagnetic with two unpaired electrons ( = 1) and can be utilized as versatile building blocks for higher-order structures, such as supramolecular complexes, coordination polymers, and metal-organic frameworks, although they are generally highly air-sensitive. In this study, we developed an air-stable paddlewheel-type diruthenium(II,II) complex with two electron-withdrawing 1,8-naphthyridine-2-carboxylate (npc) ligands, [Ru(μ-npc)(OCMe)] (1). The two acetate ligands in 1 can be replaced by other carboxylate ligands; the solvothermal reactions of 1 with benzoic acid (HOCPh) yields the heteroleptic [Ru(μ-npc)(OCPh)] (2), whereas its reaction with 1,8-naphthyridine-2-carboxylic acid (Hnpc) produces the homoleptic [Ru(μ-npc)(η-npc)] (3).
View Article and Find Full Text PDFChemistry
January 2025
Brandeis University, Chemistry, 415 South Street,, Waltham, 02453, UNITED STATES OF AMERICA.
We designed and synthesized three diacetylene monomers M1-M3 having two NH2 groups. As anticipated, the NH2 groups aided the preorganization of these monomers by N-H…N hydrogen bonding. In the crystals of monomer M1 and M2, the intermolecular N-H…N hydrogen bonding preorganized the diyne units in an orientation suitable for their topochemical polymerization, but in the case of monomer M3, the distance was slightly larger than that recommended for the topochemical reaction.
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