Synthesis and Characterization of a Bisadduct of La@C₈₂

Abstract

A bisadduct of La@C82 has been synthesized in a good yield by a Bingel-Hirsch reaction. Its structure has been well-defined by X-ray crystallographic analysis. A pair of enantiomers of the adduct form a dimer in the single crystal.

“Open Rather than Closed” Malonate Methano-Fullerene Derivatives. The Formation of Methanofulleroid Adducts of Y3N@C80

“…The bond energies for the products of the Bingel-Hirsch reaction to the [5,6] and [6,6] bonds of C80 are -63.9 and -57.9 kcal/mol, respectively. "Open Rather than Closed" Malonate Derivatives A R T I C L E S isomer I1 is the most stable structure, in excellent agreement with the experimental data.…”

“…However, this value may be misleading because the site has low occupancy and only one nitrogen atom position at the center of the endohedral has been defined. It is important to note that the Y 3 N group in the [5,6] pyrrolidine adduct, Y 3 N@C 80 -(CH 2 ) 2 -NEt, is slightly pyramidalized with the sum of the three Y-N-Y angles being 358.8°. 9 The flattening of the Y 3 N group in the Bingel-Hirsch adduct Y 3 N@C 80 -C(CO 2 CH 2 Ph) 2 may well be the result of the additional space provided inside the cage by the opening of the C1-C9 bond in the adduct.…”

“…On the other hand, the 1,3-dipolar cycloaddition occurred at a [6,6] double bond junction for Y 3 N@C 80 and Er 3 N@C 80 . These [6,6] monoadducts proved to be the kinetic product, and they underwent rearrangement to the thermodynamically more stable [5,6] monoadducts upon heating. 6 Recently, 7 both the [6,6] and the [5,6] pyrrolidine monoadducts of Sc 3 N@C 80 were isolated when an N-trityl azomethine ylide was employed instead of N-methyl or N-ethyl analogues.…”

Emergence of Highly Elaborated π-Space and Extending Its Functionality Based on Nanocarbons: New Vistas in the Fullerene World

“…However, the selectivity of Ad addition is low when the specific localization of the negative charges and the POAV values on fullerene cages is not apparent, as seen in reactions with Sc@C 2v (9)-C 82 (Figure 15a). In fact, nucleophiles selectively attack one of them to afford the corresponding monoadducts 113 and bisadducts 114 in the BingelHirsch reaction. Its mechanism is regarded as involving the nucleophilic attack of a carbanion produced in situ by deprotonation of α-halo esters or α-halo ketones.…”

Buckyballs

“…In all these fullerene cages filled with a single metal, the metal is not in the center of the cage but tends to coordinate with the cage carbons, being situated under a hexagonal ring along the C 2 axis. As a result, the distribution of charge density is highly anisotropic over the surface, with electrophiles and nucleophiles selectively attacking the two different regions [190].…”