`Nitrogen doped' C60 dimers (N@C60–C60)

Spin Quantum Computing with Endohedral Fullerenes

“…Covalent modifications have been investigated since the early days: Dietel et al have shown the first mono-adducts characterized by D values of around 10 MHz, and regio-selective attachment of up to six addends of N@C60, affording a nearly cubic hexakis adduct. 74 Franco et al have systematically varied addends in monoadducts and investigated their effect on D. 75 First fullerene dimers were reported by Goedde et al 76 and many contributions were made by the Porfyrakis group. 53,57,77,78 Covalent functionalization leads to D values of up to 15 MHz for N@C60 (comparable to the hyperfine interaction), but the resulting EPR spectra are usually broad and of little use for quantum information due to random orientation of the molecular axes induced by the covalent addends.…”

“…The main reason is the low overall synthesis yield of endohedral fullerenes, which makes chemical coupling reactions hard to realize. Although C60 dimers can be easily produced and 'half-endohedral' dimers have been demonstrated using various approaches, 76,77 all coupling reactions bear the inherent danger of spin loss. The Porfyrakis group has studied this problem in some detail; recent achievements include nearly lossless Bingel reactions 57 as well as more sophisticated dimer coupling schemes 77 that take into account the limitations of low-yield endohedral synthesis.…”

Control of C₆₀ Behavior for High Yield Synthesis of N@C₆₀ in RF-Plasma

“…Then, the compound including C 60 and N@C 60 is dissolved in toluene. [9] The solution, which contains N@C 60 and C 60 , is analyzed by electron spin resonance (ESR) and ultraviolet-visible absorption spectroscopy (UV-vis). The purity is defined as the molar concentration ratio of N@C 60 to C 60 (N@C 60 /C 60 ) dissolved in the solvent, which are estimated by ESR and UV-vis measurements, respectively.…”

“…One is to clarify the encapsulation mechanism of the nitrogen atom into C 60 , and to control the plasma parameter to the best condition. The other is to control C 60 behavior, i.e., to sublimate C 60 in dispersed form, which contributes to an increase in the reaction between C 60 and nitrogen ions to form N@C 60 [9].…”

Solvent‐Free Carbon‐Carbon Bond Formations in Ball Mills

“…[51,52] To stop the reaction at the dimer or trimer stage is difficult and, commonly, mixtures of products result. In 1997, however, Komatsu and co-workers found that mixing of C 60 (58) and KCN (20 equivs.) in a vibration ball mill (50 Hz, 30 min) led to dumb-bell shaped C 120 (60) in 30 % yield (Scheme 17).…”