In-situ characterization of C60 coalescence reaction

UV radiation-induced coalescence reaction of C60 were in situ monitored by Raman spectroscopy for the first time, and the process was also characterized by STM and laser desorption mass spectrometry. The Raman measurement reveal that, after the coalescence reaction, the vibration bands corresponding to the highly symmetric Ag mode of the C60 molecules either disappear or become very weak, while the bands from other vibration modes just get broaden and red-shifted, suggesting that the coalesced products are larger conjugated molecules but with lower symmetry. The STM measurements show the growth of the coalesced products which eventually form a film.