Persistant Organic High-Spin Trinitrenes

Persistent Organic High-Spin Trinitrenes
E. Medez-Vega, J. Mieres-Perez, S. V. Chapyshev, W. Sander, Angew. Chem. Int. Ed. 58 (2019), 12720.

The septet ground state trinitrenes 1,3,5-trichloro-2,4,6-trinitrenobenzene and 1,3,5-tribromo-2,4,6-trinitrenobenzene were isolated in inert (Ar, Ne, and Xe) as well as reactive matrices (H2, O2, and H2O) at cryogenic temperatures. These trinitrenes were obtained in high yields by UV photolysis of the corresponding triazides and characterized by IR and UV–vis spectroscopy. The trinitrenes, despite bearing six unpaired electrons, are remarkably unreactive towards molecular oxygen and hydrogen and are persistent in water ice up to 160 K where the water matrix starts to sublime off.

Read the article in Angew. Chem.




M. Winkler, W. Sander, Acc. Chem. Res. 47 (2014), 31-44.


Consistent with the definition of diradicals, triradicals are species in which three electrons occupy three (nearly) degenerate orbitals, resulting in close-​lying quartet and doublet states. The same concepts and rules that can be used to predict and rationalize the ground state multiplicity of diradicals also apply to triradicals, but the greater no. of states in triradicals generally leads to more complex electronic structures.

Read our publication in Acc. Chem. Res.




1,3,5-TrimethylenbenzeneThe highly symmetrical quartet triradical trimethylenebenzene has been isolated for the first time (see structure). Despite its open-shell character, it was photochemically stable and this makes it a promising building block for magnetic materials.

Isolation and Characterization of the Triradical 1,3,5-Trimethylenebenzene
P. Neuhaus, W. Sander, Angew. Chem. Int. Ed., 49 (2010), 7277-7280.

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Research highlights at nature.com


Some diradicals investigated in our laboratory



Didehydro and Tridehydrobenzenes

Di- and tridehydrobenzenes that have been for the first time spectroscopically characterized in our group are shown in yellow.


Nitrene Radical vs. Carbene

An unusual nitrene radical with a quartet electronic ground state compared to a carbene. Both molecules have been characterized by IR and EPR spectroscopy.