Prof. John A. Gladysz, Texas A&M University College of Arts & Sciences, USA

“From Molecular Gyroscopes to Homeomorphic Isomerization: Molecules that Turn Themselves Inside-Out”

The Houdini-like escape of metal fragments from the cage-like dibridgehead diphosphine ligands of so-called "gyroscope-like" complexes (e.g., 1) will be described. The resulting diphosphines P((CH2)n)3P (2) can exist as in,in, out,out, and in,out isomers. The in,in and out,out isomers can interconvert by "homeomorphic isomerization" (3), a process that turns a molecule inside-out, like an article of clothing, exchanging exo and endo functionality. At temperatures sufficient for pyramidal inversion at phosphorus (ca. 150 °C), the in,in and out,out isomers equilibrate with in,out isomers. Trends in the rates and K(eq) values will be interpreted, together with a wealth of crystallographic data.

Metal complexes are easily reconstituted from the "empty" dibridgehead diphosphines 2. Ap­plications of these phenomena in the selective binding and transport of various metal fragments will be reported. The synthesis and properties of analogous diphosphine dioxides, diarsines, and di(triaryl)phosphines will also be described. 

References

(1) Lang, G. M.; Shima, T.; Wang, L.; Cluff, K. J.; Skopek, K.; Hampel, F.; Blümel, J.; Gladysz, J. A. J. Am. Chem. Soc. 2016, 138, 7649.

(2) Kharel, S.; Joshi, H.; Bierschenk, S.; Stollenz, M.; Taher, D.; Bhuvanesh, N.; Gladysz, J. A. J. Am. Chem. Soc. 2017, 139, 2172.

(3) Joshi, H.; Kharel, S.; Ehnbom, A.; Skopek, K.; Hess, G. D.; Fiedler, T.; Hampel, F.; Bhuvanesh, N.; Gladysz, J. A. J. Am. Chem. Soc. 2018, 140, 8463.

(4) Ehnbom, A.; Gladysz, J. A. Chem. Rev. 2021, 121, 3701.

(5) Estrada, A. L.; Wang, Y.; Hess, G.; Hampel, F.; Gladysz, J. A. Inorg. Chem. 2022, 61, 17012.

(6) Zhu, Y.; Stollenz, M.; Zarcone, S. R.; Kharel, S.; Hemant, J.; Bhuvanesh, N.; Reibenspiess, J. H.; Gladysz, J. A. Chem. Sci. 2022, 13, 13368.

(7) Zarcone, S. R.; Bhuvanesh, N.; Gladysz, J. A. Chem. Eur. J. 2023, 29, e202302200.

(8) Zarcone, S. R.; Verardi, P. J.; Chu, G. M.; Bhuvanesh, N.; Gladysz, J. A. Organometallics 2024, 43, 1285-1298.

(9) Zarcone, S. R.; Zhang, Z.; Handunneththige, S.; Ni, Z.; Bhuvanesh, N.; Nippe, M.; Mey­er, K.; Hall, M. B.; Gladysz, J. A. Inorg. Chem. 2024, 63,