The Existence of Stable Tm@C₈₂ Isomers

Abstract

Endohedral fullerene compounds with isomeric carbon frameworks have been identified for the first time. The three stable isomers of Tm2+@C 822− were separated by HPLC, and characterized by cyclic voltammetry and by UV/Vis/NIR and 13C NMR spectroscopy as probably having C2, Cs, and C3v symmetry (see picture).

Discrete Fulleride Anions and Fullerenium Cations

“…The triplet features (2D ) 26 G) increase in intensity with temperature, consistent with a singlet-triplet gap of 0.022 eV (180 cm -1 ). The trianion has doublet-type features with g ) 2.003 and ∆H pp ) 3.9 G. The EPR characteristics for all reduction states are consistent with a doubly degenerate ground state for the D 2d isomer of C 84 .…”

“…A number of reports on the electrochemistry of endohedral fullerenes have also appeared. 24,62,65,84,85 …”

“…This is beginning to change now that preparative amounts of C 70 , C 76 , C 78 , C 84 , and others are now commercially available.…”

“…Metal-fullerene complexes tend to dissociate upon reduction. 40 This same property in methanofullerenes (the so-called retro-Bingel reaction) has been turned to advantage in the preparation of enantiomerically pure C 76 404 and isomerically pure C 84 . 66 In certain cases, the addenda in bismethano [60]fullerenes "walk" around the sphere while in their fulleride form.…”

MonometallofullereneTm@C82: Proof of an Encapsulated Divalent Tm Ion by High-Energy Spectroscopy

“…In the past, much work has been carried out on metallofullerenes of La [3,4], Y [5], and Sc [6], whereby C 82 and C 84 form the host cages. More recently, metallofullerenes containing rare earth ions have been produced, such as Gd [7] and Tm [8].…”