Synthesis of atomic and molecular endohedral fullerenes

Hoffman, Gabriela (2021) Synthesis of atomic and molecular endohedral fullerenes. University of Southampton, Doctoral Thesis.

Record type: Thesis (Doctoral)

Abstract

This work presents syntheses of fullerene C₆₀ enclosing atoms and molecules inside its cavity. These clusters are very convenient systems to study physical and spectral properties on atomic level. Endohedral fullerenes can be synthesised by performing a sequence of chemical reactions to open a hole in C₆₀, followed by insertion of the guest atom or molecule and chemical closure. This process is known as molecular surgery. In this work, opening route to key open cage fullerene containing 12-membered ring has been improved. 12-membered ring is a key precursor to open the fullerene cavity in order to insert atoms and molecules. The synthesis has been improved to higher yielding, safer and faster process. Two novel open cage fullerenes have been isolated and crystal structures obtained. These proved to be mechanistically important for the closing steps of the fullerene. Syntheses of He@C₆₀, H₂@C₆₀ and Ne@C₆₀ have been improved and high filling factors between 50- 100% achieved. Kr@C₆₀ has been prepared for the first time by molecular surgery, isolated with 100% filling factor and a crystal structure was obtained. Finally, N2@C₆₀ was prepared as a mixture containing empty C₆₀ and H₂O@C₆₀ and the ¹³C NMR spectra was recorded for the first time.