C₆₀O₃, a Fullerene Ozonide:  Synthesis and Dissociation to C₆₀O and O₂

Abstract

An unstable intermediate has been detected and isolated in the reaction of ozone with C60 in solution. On the basis of its UV−vis absorption spectrum, the measured release of O2 in its decay to the epoxide C60O, and the first-order kinetics of this reaction, the intermediate has been identified as C60O3, a primary ozonide. This [6,6]-closed adduct of ozone with C60 thermally dissociates to C60O plus O2 in toluene solution, octane solution, and the solid phase with rate constants (at 23 °C) of 4.6 × 10-2, 1.3 × 10-3, and 3.0 × 10-3 min-1, respectively. The activation energy for dissociation in toluene solution is approximately 89 kJ mol-1. Semiempirical quantum calculations indicate that the formation and subsequent dissociation of C60O3 are both exothermic processes. These findings constitute the first observation of a fullerene ozonide.

Peroxide intermediates of oxidation processes: Organic trioxides

“…Comparison of calculated activation enthalpies (9.6 and 15.5 kJ mol −1 , respectively) shows that [6,6]-addition is energetically more favorable, which confirms the conclusions 277 about the structure of the C 60 O 3 ozonide that was isolated by the authors. The saddle point 6,6-TS has the C S symmetry ( Figure 5) that is characteristic of transition states of O 3 addition to double bonds of symmetric alkenes.…”

“…In the case of C 60 O 3 thermal decay, maxima at 328 and 424 nm as well as a diffuse maximum at 490 nm appear in the spectrum of the reaction mixture, which indicate that C 60 O epoxide is formed. On the basis of the changes in the intensity of the peak at 424 nm, the rate constant of C 60 O 3 thermal decay was found to be 7.7 × 10 −4 s −1 (296 K), the activation energy of thermal decay is 89.4 kJ mol −1 , whereas the pre-exponential factor is typical of monomolecular dissociation through rotational movement 277 .…”

“…Fullerene ozonides, along with perfluorotrioxides, are the most long-living polyoxide species. It fact, their thermal stability, which is extraordinary for compounds with a chain of three covalent-bound oxygen atoms, made it possible to isolate ozonides in preparative amounts by high-performance liquid chromatography (HPLC) and characterize them by electron [277][278][279]IR 280 , and 13 C NMR spectroscopy (only cc-C 70 O 3 ) 279 .…”

“…Fullereno-1,2,3-trioxolanes C 60 (O 3 ) x , x = 1-3 277,278 , ab-C 70 O 3 , and cc-C 70 O 3 279 were identified as primary products of C 60 and C 70 reactions with ozone. The preparation conditions, the specific features of the absorption spectra of fullereno-1,2,3-trioxolanes, and their conversion products are presented in Table 16.…”

Theoretical study of the corannulene ozonolysis and evaluation of the various reaction paths

“…The ozonization of C 60 and the dissociation of the formed ozonide C 60 O 3 have been investigated theoretically at the AM1 level of theory [24] and experimentally [25,26]. Heymann et al have presented their complete study of the ozonization of C 60 and C 70 and the subsequent photolysis and thermolysis of the formed ozonides [27,28]. The ozonolysis of C 60 and C 70 theoretically have studied by means of the AM1 and DFT methods [29][30][31][32].…”