Tetrahedral metal-organic cages with cube-like cavities for selective encapsulation of fullerene guests and their spin-crossover properties.

Tetrahedral FeII4L6 coordination cages containing organic linkers with rigid π-electron aromatic rings and flexible alkyl units were constructed. Interestingly, these tetrahedral cages have rare cube-like cavities for selective encapsulation of fullerene guests. In addition, the solid state spin-crossover properties were influenced by guest binding of fullerene C60.