The reaction mechanism for the cycloaddition of CO to styrene oxide in the presence of macrocyclic pseudopeptides has been studied using DFT methods. Computational calculations indicate that the unprecedented catalytic behaviour previously observed experimentally, in which the most reactive species was not the most nucleophilic but the most basic one, can be associated to the tight cooperativity between several supramolecular interactions promoted by simple peptidomimetics able to display a synzymatic behaviour. This bizarre catalytic performance afforded remarkable conversions of a sluggish substrate like styrene oxide into the desired cyclic carbonate, even under relatively mild reaction conditions, opening the way for the practical use of CO as a raw material in the preparation of valuable chemicals. Furthermore, the remote modification of essential structural features of the macrocycle (synzyme engineering) permitted the driving forces of the synzymatic system to be analyzed, stressing the crucial synergic effect between an elegantly preorganized oxyanion hole and additional aromatic interactions.
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http://dx.doi.org/10.1039/d2ob00948j | DOI Listing |
Nat Commun
January 2025
Department of Physics, University of Michigan, Ann Arbor, MI, USA.
Excitons, bound electron-hole pairs, influence the optical properties in strongly interacting solid-state systems and are typically most stable and pronounced in monolayer materials. Bulk systems with large exciton binding energies, on the other hand, are rare and the mechanisms driving their stability are still relatively unexplored. Here, we report an exceptionally large exciton binding energy in single crystals of the bulk van der Waals antiferromagnet CrSBr.
View Article and Find Full Text PDFNat Commun
January 2025
Shanghai Key Laboratory MFree, Institute for Shanghai Advanced Research in Physical Sciences, Shanghai, 201203, China.
In recent years, metal hydride research has become one of the driving forces of the high-pressure community, as it is believed to hold the key to superconductivity close to ambient temperature. While numerous novel metal hydride compounds have been reported and extensively investigated for their superconducting properties, little attention has been focused on the atomic and electronic states of hydrogen, the main ingredient in these novel compounds. Here, we present combined H- and La-NMR data on lanthanum superhydrides, LaH, (x = 10.
View Article and Find Full Text PDFPhilos Trans A Math Phys Eng Sci
January 2025
Binghamton Center of Complex Systems, Binghamton University, State University of New York, Binghamton, NY 13902, USA.
Artificial swarm systems have been extensively studied and used in computer science, robotics, engineering and other technological fields, primarily as a platform for implementing robust distributed systems to achieve pre-defined objectives. However, such swarm systems, especially heterogeneous ones, can also be utilized as an ideal platform for creating open-ended evolutionary dynamics that do not converge toward pre-defined goals but keep exploring diverse possibilities and generating novel outputs indefinitely. In this article, we review Swarm Chemistry and its variants as concrete sample cases to illustrate beneficial characteristics of heterogeneous swarm systems, including the cardinality leap of design spaces, multi-scale structures/behaviours and their diversity, and robust self-organization, self-repair and ecological interactions of emergent patterns, all of which serve as the driving forces for open-ended evolutionary processes.
View Article and Find Full Text PDFCurr Biol
January 2025
Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Department of Pathology, Brigham and Women's Hospital, Boston, MA 02115, USA. Electronic address:
The vertebrate bauplan is primarily established via the formation of embryonic tissues in a head-to-tail progression. The mechanics of this elongation, which requires the presomitic mesoderm (PSM), remain poorly understood. Here, we find that avian PSM explants can elongate autonomously when physically confined in vitro, producing a pushing force promoting posterior elongation of the embryo.
View Article and Find Full Text PDFSci Adv
January 2025
Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China.
Ice core measurements reveal dipole-like snow accumulation trends over West Antarctica throughout the 20th century, with an increase of >2000 billion metric tons over the Antarctic Peninsula and Ellsworth Land but a decrease of ~500 billion metric tons over Marie Byrd Land. Although atmospheric teleconnections were frequently revealed, linking variability between tropics and higher latitudes on interannual and decadal timescales, centennial-scale teleconnection is absent from literature. Here, using statistical analysis and numerical experiments, we reveal that changes of tropical oceans throughout the 20th century drive the long-term Antarctic snowfall trend.
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