In English

Abstract

Experimental and theoretical aspects of fullerene C60 ionization, fragmentation and aggregation are discussed by laser desorption/ionization mass spectrometry and quantum chemistry. Ion formation and chemical reactions of fullerene molecule depend essentially upon the nature and properties of the surface where it is deposited as well as upon the conditions of deposition and the mechanisms of ion-molecular reactions which occur in the ion source of mass spectrometer.It has been shown that the energy of single photon is enough to ionize an adsorbed fullerene molecule due to transition of single electron to the Fermi level of support and consequent overcoming the barrier of image forces. Nevertheless, this mechanism cannot explain the observed mass spectra completely, in particular the high level of fullerene fragmentation, because of lack of photon energy. Plasmon resonance resulted from multi-photon excitation of fullerene molecule in condensed state is the initial stage and the main mechanism of energy supply for fullerene laser induced ionization, fragmentation, aggregation, and chemical reactions which take place in both adsorbed state and ion plum. Explanation of observed experimental results concerning fullerene fragmentation and aggregation is proposed based on the results of quantum chemical calculations and on heuristic considerations.