The remarkable chemistry of trannulenes: green fluorinated fullerenes with unconventional aromaticity.
We report the first reaction of trannulenes involving their thermal isomerization to a new class of compounds termed "triumphenes". The thermodynamically controlled conversion of trannulenes into triumphenes is accompanied by an unprecedented migration of three organic addends from one hemisphere of the fullerene cage to another. The reaction products, bearing aliphatic substituents, might find applications in materials science as strong electron acceptors due to the presence of fifteen electron-withdrawing fluorine atoms in their molecular framework. It was revealed that the isomerization of trannulenes can be affected by the presence of unsaturated compounds in the reaction mixture. Heating of trannulenes C(60)F(15)R(3) with C(60), C(70), anthracene, or pentacene at reflux in 1,2-dichlorobenzene yields fluorinated derivatives C(60)F(14)R(2)A, which possess a fused cyclic addend A. The products of this reaction have "triumphene-type" addition patterns and seem to be formed through an unprecedented sequence of elimination, addition, and isomerization steps. The molecular structure of a representative triumphene was proven unambiguously by X-ray single-crystal diffraction analysis and by NMR spectroscopy. The reactions revealed here open up numerous opportunities for chemical derivatization of fluorinated fullerenes. This method promises to provide a new path towards valuable photoactive materials and a new generation of fullerene-based compounds that are suitable for biomedical applications.
Khakina
Ekaterina A
EA
Institute of Problems of Chemical Physics of Russian Academy of Sciences, Semenov Prospect 5, Chernogolovka, Moscow region, 142432, Russia.
Troyanov
Sergey I
SI
Peregudov
Alexander S
AS
Soulimenkov
Ilya V
IV
Polyakova
Natalya V
NV
Troshin
Pavel A
PA
D018360:Crystallography, X-Ray; D037741:Fullerenes / Q000737:chemistry*; D054879:Halogenation; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D013816:Thermodynamics
D037741:Fullerenes