Dimerization of Endohedral Fullerene in a Superatomic Crystal

Abstract

We describe a solid state material created from the reaction of Ni9Te6(PEt3)8 and Lu3N@C80. The resulting superatomic crystal, [Ni12Te12(PEt3)8]2[(Lu3N@C80)2], contains dimers of Lu3N@C80 that form upon reduction of the fullerene through a single C−C bond at the triple hexagon junctions. The encapsulated Lu3N cluster displays an unprecedented orientation that is collinear and coplanar with the intercage carbon bond. Density functional theory calculations rationalize this unique bonding and relative orientation of the Lu3N clusters. Our structural and theoretical results provide new insights into the effect that the M3N cluster species has on the dimerization process of endohedral fullerenes.

Molecular Structure and Magnetic and Optical Properties of Endometallonitridofullerene Sc3N@Ih‐C80 in Neutral, Radical Anion, and Dimeric Anionic Forms

“…Endometallofullerenes can show promising magnetic properties, such as single‐molecule magnet behavior, and semiconducting properties even in the neutral state . Anionic compounds based on endometallofullerenes are still rather rare, and only two compounds with dimerized endometallofullerene anions have been obtained . Due to the high tendency to dimerize in both solution and the solid state, monomeric endometallofullerene radical anions were not obtained for a long time.…”

“…In agreement with the experimental data, DFT calculations showed a distortion of the cluster shape in the dimer and an intercage C−C bond of 1.598 Å . Note that the orientation of the Sc 3 N cluster in (Sc 3 N@C 80 − ) 2 differs from that of the cluster in the (Lu 3 N@C 80 − ) 2 dimer, which also crystallizes as a 666 isomer but has a different orientation of the Lu 3 N cluster with a single lutetium atom facing the intercage bonding site …”

“…ter in (Sc 3 N@C 80 À ) 2 differs from that of the cluster in the (Lu 3 N@C 80 À ) 2 dimer,w hich also crystallizes as a6 66 isomer but has ad ifferent orientation of the Lu 3 Nc luster with as ingle lutetium atom facing the intercage bondings ite. [16] Ac loser look at the orientations of the Sc 3 Nc lusters howed that to ag reat extent the disorderi sc aused by the symmetry of the hostingf ullerene. Without the endohedral cluster,t he 666 isomer of the (I h -C 80 ) 2 dimer has idealized D 3d molecular symmetry,w hereas the site symmetryo ft he monomerf ragment is C 3v (the C 3 symmetry axis lies along the intercage CÀC bond).A pplying the symmetry operations of this group to the major cluster orientation, two more equivalent positionsw ere obtained.…”

“…[11,14] Anionic compounds based on endometallofullerenes are still rather rare, and only two compounds with dimerized endometallofullerene anions have been obtained. [15,16] Due to the high tendency to dimerize in both solution and the solid state, [15][16][17] monomeric endometallofullerene radicala nions were not obtained foral ong time. Only recently have endometallofullerener adical anions been stabilized in the solids tate by using organic cations of special shape to preventt heir dimerization in the crystal.…”

Structure of [60]fullerene with a mobile lithium cation inside

“…A crystal of dimerized Li + @C 60 − without anions was also obtained by electrochemical reduction [22]. The crystal is different from other dimerized endohedral metallofullerene crystals that consist of negatively charged endohedral metallofullerenes and positively charged donor molecules [23,24]. The Li + cation in the dimerized Li + @C 60 − is localized near the carbon atom that is nearest to the carbon atom forming an inter-fullerene single C–C bond at 100 K. Temperature dependence of the position and motion of the localized Li + cation in the dimerized Li + @C 60 − would provide us with essential information about the thermal stability of the (Li + @C 60 − ) 2 dimer and the Li + –C bond.…”