Investigations into the reactivity, properties, and applications of osmium(IV) tetraaryl complexes have been hampered by their low yielding syntheses from volatile and toxic OsO4 (typically ≤34%). Here we show that known air-stable M(aryl)4 compounds (M = Os, Ru; aryl = 2-tolyl, 2,5-xylyl) can be prepared in ≤73% yields using new, less hazardous (Oct4N)2[MX6] precursors (M = Os, Ru; X = Cl, Br). This approach also facilitates the preparation of Os(mesityl)4 (Os3) for the first time, a complex comprising bulky 2,6-dimethyl substituted aryl ligands, albeit in low yield (5%). To better understand these yield extremes, we track, by synthesizing two additional new complexes with different 2-substituted σ-aryl ligands, a clear relationship between the yields of Os(aryl)4 and ligand steric bulk. Single-crystal X-ray structures of these compounds indicate that the observed yield trend reflects the ease of accommodating aryl substituents into an open pocket that lies directly opposite each M-aryl coordination site. We perform variable-temperature 1H NMR studies of Os3, utilize a "tetrahedricity" metric to assess geometric distortion in Ru(aryl)4 and Os(aryl)4 materials, and calculate cone angle and percentage buried volume metrics to further illustrate and help quantify -aryl ligand steric properties. Solution cyclic voltammograms of Os(aryl)4 show that the potentials ofmore »
Moving beyond the constraints of chemistry via crystal structure discovery with isotropic multiwell pair potentials
The rigid constraints of chemistry—dictated by quantum mechanics and the discrete nature of the atom—limit the set of observable atomic crystal structures. What structures are possible in the absence of these constraints? Here, we systematically crystallize one-component systems of particles interacting with isotropic multiwell pair potentials. We investigate two tunable families of pairwise interaction potentials. Our simulations self-assemble a multitude of crystal structures ranging from basic lattices to complex networks. Sixteen of the structures have natural analogs spanning all coordination numbers found in inorganic chemistry. Fifteen more are hitherto unknown and occupy the space between covalent and metallic coordination environments. The discovered crystal structures constitute targets for self-assembly and expand our understanding of what a crystal structure can look like.
- Publication Date:
- NSF-PAR ID:
- 10228922
- Journal Name:
- Proceedings of the National Academy of Sciences
- Volume:
- 118
- Issue:
- 21
- Page Range or eLocation-ID:
- Article No. e2024034118
- ISSN:
- 0027-8424
- Publisher:
- Proceedings of the National Academy of Sciences
- Sponsoring Org:
- National Science Foundation
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