Laser MS study of self-assembled mono- and dilayer film of C-60 with ethylene diamine as intermolecular string

Self-assembled film of C-60 with ethylene diamine as intermolecular string were analyzed by the method of laser time-of-flight mass spectrometry. Simi lar mass spectra were found for self-assembled monolayer film of C-60 on gl ass or silicon surface. For die glass film, the highest ion was C-112(+), w hile for silicon film was C-102(+). When n>32, the fragmentation of C-n, sh owed the lost of two carbon atoms each time. And the adduct (C-60+ ethylene diamine) wasn't found in the spectra. It was assumed that at such a condit ion only C-60 and its dimer are desorbed. The reason was that the bond betw een ethylene diamine and the surface of glass or silicon were stronger than that between ethylene diamine and C-60. The spectra of self-assembled dila yer film of C-60 was different from that of monolayer film. In the spectra of dilayer film, when m/z<600, few peaks were found; when 600<m/z<720, the spectra had the characteristic fragmentary spectra of pure C-60; when m/z>7 20, there was a broad peak. The above results demonstrated that laser MS ca n provide useful structural information in the study of fullerene film.