UV radiation-induced coalescence reaction of C-60 were in situ monitored by
Raman spectroscopy for the first time, and the process was also characteri
zed by STM and laser desorption mass spectrometry. The Raman measurement re
veal that, after the coalescence reaction, the vibration bands correspondin
g to the highly symmetric A(g) mode of the C-60 molecules either disappear
or become very weak, while the bands from other vibration modes just get br
oaden and red-shifted, suggesting that the coalesced products are larger co
njugated molecules but with lower symmetry. The STM measurements show the g
rowth of the coalesced products which eventually form a film. (C) 1999 Else
vier Science B.V. All rights reserved.