Journalartikel

Jahr der Veröffentlichung: 2018

Seiten: 505-510

Zeitschrift: Nature

Bandnummer: 554

DOI Link: https://doi.org/10.1038/nature25765

Verlag: Nature Research

Abstract: 

Mechanical stimuli can modify the energy landscape of chemical reactions
and enable reaction pathways, offering a synthetic strategy that
complements conventional chemistry^1,2,3. These mechanochemical mechanisms have been studied extensively in one-dimensional polymers under tensile stress^4,5,6,7,8,9 using ring-opening¹⁰ and reorganization¹¹, polymer unzipping^6,12 and disulfide reduction^13,14
as model reactions. In these systems, the pulling force stretches
chemical bonds, initiating the reaction. Additionally, it has been shown
that forces orthogonal to the chemical bonds can alter the rate of bond
dissociation¹⁵.
However, these bond activation mechanisms have not been possible under
isotropic, compressive stress (that is, hydrostatic pressure). Here we
show that mechanochemistry through isotropic compression is possible by
molecularly engineering structures that can translate macroscopic
isotropic stress into molecular-level anisotropic strain. We engineer
molecules with mechanically heterogeneous components—a compressible
(‘soft’) mechanophore and incompressible (‘hard’) ligands. In these
‘molecular anvils’, isotropic stress leads to relative motions of the
rigid ligands, anisotropically deforming the compressible mechanophore
and activating bonds. Conversely, rigid ligands in steric contact impede
relative motion, blocking reactivity. We combine experiments and
computations to demonstrate hydrostatic-pressure-driven redox reactions
in metal–organic chalcogenides that incorporate molecular elements that
have heterogeneous compressibility^16,17,18,19,
in which bending of bond angles or shearing of adjacent chains
activates the metal–chalcogen bonds, leading to the formation of the
elemental metal. These results reveal an unexplored reaction mechanism
and suggest possible strategies for high-specificity mechanosynthesis.

Harvard-Zitierstil: Yan, H., Yang, F., Pan, D., Lin, Y., Hohman, J., Solis-Ibara, D., et al. (2018) Sterically controlled mechanochemistry under hydrostatic pressure, Nature, 554, pp. 505-510. https://doi.org/10.1038/nature25765

APA-Zitierstil: Yan, H., Yang, F., Pan, D., Lin, Y., Hohman, J., Solis-Ibara, D., Li, F., Dahl, J., Carlson, R., Tkachenko, B., Fokin, A., Schreiner, P., Galli, G., Mao, W., Shen, Z., & Melosh, N. (2018). Sterically controlled mechanochemistry under hydrostatic pressure. Nature. 554, 505-510. https://doi.org/10.1038/nature25765