The Orthogonal (e,e,e)‐Tris‐Adduct of 9,10‐Dimethylanthracene with C₆₀‐Fullerene: A Hidden Cornerstone of Fullerene Chemistry. Preliminary Communication

Abstract

Tris(9',10]ethanoanthracene [11',12': 1,9;11'',12'': 16,17;11''',12''': 30,31]) [5,6]fullerene C 60 , the orthogonal (e,e,e)-tris-adduct of C 60 and 9,10-dimethylanthracene, was obtained from [4 þ 2]-cycloaddition (Diels -Alder reaction) at room temperature. The thermally unstable orange red (e,e,e)-tris-adduct was purified by chromatography and was isolated in the form of red monoclinic crystals. Its C 3 -symmetric addition pattern was established spectroscopically. Its structure could be further investigated by single crystal X-ray diffraction. The (e,e,e)-tris-adduct of C 60 and 9,10-dimethylanthracene has earlier been suggested as intermediate and reversibly formed critical component in template directed addition reactions of C 60 . This previously elusive compound has now been isolated and structurally characterized.Introduction. -The discovery of the fullerenes [1] and of an efficient method to produce substantial amounts of these spherical carbon molecules [2] has opened a new era of chemistry [1] [3 -5] and has paved the way to synthetic, spectroscopic, and structural studies [6]. One major goal of these studies concerned the exploration of methods to achieve specific exohedral modifications of the symmetric spherical C- . In other cases, the thermal reversibility was exploited to achieve reversible attachment of fullerenes to solid support [19].As the highly symmetrical C-sphere provided by the [5,6]fullerene 1 represents a unique basis for building up three dimensional molecular structures by multiple exohedral functionalization, particular attention was paid to the problem of regioselectivity in functionalization reactions [7] [8]. The underlying need for regiocontrol has provoked extensive studies on i) the patterns of the inherent reactivity of [5,6]fullerene

Remendable polymers via reversible Diels–Alder cycloaddition of anthracene‐containing copolymers with fullerenes

“…Although the 1 H NMR studies in solution may not be directly applicable to the solid bulk material, those measurements are still useful for understanding of the time scale in relation to DA reaction conversion. Due to the highly reversible system, the final conversion within the bulk materials was uncertain.…”

“…reported a DA cycloaddition of a bis‐ anthracene ester with C 60 ‐fullerene in the solid state by mechanochemical preparation and investigated a dissociation in the temperature range 40–65 °C. Kräutler and coworkers investigated intensively the formation of mono‐ and bis‐ adducts in the solid state and solution as well as the formation of different regioisomers and the decomposition reaction. Moreover, the authors reported the instability of the bis‐ and tris‐ adducts resulting in rapid rDA reactions.…”

Invertomers of Fullerenophosphates

“…Recently, we reported the crystal structure of a pentakisadduct with an incomplete octahedral addition pattern and Chronakis and co‐workers published the structure of a trisadduct with e edge , e face , trans ‐ 1 ‐geometry 17. An e , e , e ‐tris‐dimethylanthracene adduct was the only other fullerene derivative with an e , e , e ‐addition pattern that was crystallized to date 18. The single crystals of the P in ‐isomer 18 were grown from hot [D 8 ]toluene solution.…”

Molecular self-healing mechanisms between C60-fullerene and anthracene unveiled by Raman and two-dimensional correlation spectroscopy

“…54,56 The time-dependent measurements were performed as follows: first two spectra were recorded at ambient temperature. All Raman spectra contained slight contaminations of anthracene, which stems from the unavoidable degradation of the Diels-Alder adducts.…”