Enantiopure Polyradical Tetrahedral Pd12L6 Cages

The synthesis of cages with a polyradical framework remains a challenging task. Herein is reported an enantiomeric pair of quinoid‐bridged polyradical tetrahedral palladium(II) cages that are stabilized by an unusual dianionic diradical form (dhbq..2−). These cages have been characterized by electron paramagnetic resonance and UV‐visible spectroscopy, squid magnetometry and mass spectrometry. Single‐crystal‐derived X‐ray investigations of the iso‐structural cages built on fluoranilate linkers confirm the tetrahedral structure of the obtained radical cages. Theoretical calculations showed that the diradical state of the dhbq anions is more stable than the usual monoradical state. A weak ferromagnetic exchange between adjacent radical centers was observed in DFT studies. Polyradical captured in a cage: Chiral polyradical PdII tetrahedral cages supported by tris(imido)phosphate trianions and diradical dhbq••2− linkers were synthesized. DFT calculations show that these cages exhibit integer spin states and ferromagnetic exchange between the adjacent radical bridges via the PdII atoms. This work provides insights into the design and synthesis of stable cage frameworks with potential in the areas of spin‐electronic devices and catalysis.