Synthesis, X-ray single-crystal structure determination, and magnetic properties of [Rb(benzo[18]crown-6)](+) salts containing well-ordered fulleride trianions C60(3-).

Finally, a structure with well-resolved C(60) (3-) ions and S=1/2 spin system: The two novel title compounds have clearly S=1/2 and not S=3/2 electronic states, as expected for the occupation of the triply degenerate LUMO of C(60.) These structures with well-ordered fullerene trianions show that the expected Jahn-Teller distortion is not observable in X-ray diffraction experiments.Crystals of the composition [Rb(benzo[18]crown-6)](3)[eta(3)-C(60)](C(7)H(8))(C(3)H(7)NO)(4.