Owing to the strength of the C-F bond, the 'direct' preparation of Grignard reagents, i.e., the interaction of elemental magnesium with an organic halide, typically in an ethereal solvent, fails for ...bulk magnesium and organofluorine compounds. Previously described mechanochemical methods for preparing Grignard reagents have involved ball milling powdered magnesium with organochlorines or bromines. Activation of the C-F bond through a similar route is also possible, however. For example, milling 1- and 2-fluoronaphthalene with an excess of magnesium metal for 2 h, followed by treatment with FeCl
and additional milling, produces the corresponding binaphthalenes, albeit in low yields (ca. 20%). The yields are independent of the particular isomer involved and are also comparable to the yields from corresponding the bromonaphthalenes. These results may reflect similar charges that reside on the α-carbon in the naphthalenes, as indicated by density functional theory calculations.
The “disappearing polymorph” phenomenon is well established in organic solids, and has had a profound effect in pharmaceutical materials science. The first example of this effect in metal‐containing ...systems in general, and in coordination‐network solids in particular, is here reported. Specifically, attempts to mechanochemically synthesize a known interpenetrated diamondoid (dia) mercury(II) imidazolate metal–organic framework (MOF) yielded a novel, more stable polymorph based on square‐grid (sql) layers. Simultaneously, the dia‐form was found to be highly elusive, observed only as a short‐lived intermediate in monitoring solvent‐free synthesis and not at all from solution. The destabilization of a dense dia‐framework relative to a lower dimensionality one is in contrast to the behavior of other imidazolate MOFs, with periodic density functional theory (DFT) calculations showing that it arises from weak interactions, including structure‐stabilizing agostic C−H⋅⋅⋅Hg contacts. While providing a new link between MOFs and crystal engineering of organic solids, these findings highlight a possible role for agostic interactions in directing topology and stability of MOF polymorphs.
Mechanochemical synthesis of mercury(II) imidazolate reveals a layered framework that is, based on reaction monitoring and theoretical calculations, more stable than the previously reported interpenetrated polymorph. The stabilization highlights a role for weak agostic contacts in MOF stability, whereas the inability to reproduce the previously known form represents the first example of the disappearing polymorph phenomenon in coordination chemistry.
A Diverse View of Science to Catalyse Change Urbina-Blanco, César A; Jilani, Safia Z; Speight, Isaiah R ...
Journal of the American Chemical Society,
08/2020, Letnik:
142, Številka:
34
Journal Article
Valuing diversity leads to scientific excellence, the progress of science and, most importantly, it is simply the right thing to do. We must value diversity not only in words, but also in actions.
A Diverse View of Science to Catalyse Change Urbina‐Blanco, César A.; Jilani, Safia Z.; Speight, Isaiah R. ...
Angewandte Chemie (International ed.),
October 12, 2020, Letnik:
59, Številka:
42
Journal Article
Recenzirano
Odprti dostop
Valuing diversity leads to scientific excellence, the progress of science and most importantly, it is simply the right thing to do. We can value diversity not only in words, but also in actions.
A diverse view of science to catalyse change Urbina-Blanco, César A; Jilani, Safia Z; Speight, Isaiah R ...
Chemical science (Cambridge),
09/2020, Letnik:
11, Številka:
34
Journal Article
Recenzirano
Odprti dostop
Valuing diversity leads to scientific excellence, the progress of science and, most importantly, it is simply the right thing to do. We can value diversity not only in words, but also in actions.
...Valuing diversity leads to scientific excellence, the progress of science and, most importantly, it is simply the right thing to do. We must value diversity not only in words, but also in actions.
A diverse view of science to catalyse change Mack, James; Yang, Ying-Wei; Wadle, Austin ...
Croatica Chemica Acta,
01/2020, Letnik:
93, Številka:
1
Journal Article, Web Resource
Recenzirano
Odprti dostop
Valuing diversity leads to scientific excellence, the progress of science and, most importantly, it is simply the right thing to do. We must value diversity not only in words, but also in actions.
...This article is co-published in the following journals: Nature Chemistry ( https://doi.org/10.1038/s41557-020-0529-x ), Chemical Science ( https://doi.org/10.1039/D0SC90150D ), Journal of the American Chemical Society ( https://doi.org/10.1021/jacs.0c07877 ), Angewandte Chemie International Edition ( https://doi.org/ 10.1002/anie.202009834 ), Canadian Journal of Chemistry ( https://doi.org/10.1139/cjc-2020-0323 ), and Croatica Chemica Acta ( https://doi.org/10.5562/diversity2020 ).
A Diverse View of Science to Catalyse Change Urbina‐Blanco, César A.; Jilani, Safia Z.; Speight, Isaiah R. ...
Angewandte Chemie,
October 12, 2020, Letnik:
132, Številka:
42
Journal Article
The “disappearing polymorph” phenomenon in metal–organic frameworks has been demonstrated and presents intermolecular agostic interactions, validated by Bader analysis of electron density shown in ...the image, as structure‐directing elements in such materials. More information can be found in the Full Paper by T. P. Hanusa, T. Friščić, et al. on page 1811.
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