화학공학소재연구정보센터
Journal of Physical Chemistry A, Vol.104, No.40, 9171-9179, 2000
Laser-induced formation, fragmentation, coalescence, and delayed ionization of the C59N heterofullerene
The formation of the nitrogen heterofullerene, C59N, following the ablation of a variety of fullerene derivatives, all of which possess organic ligands bound to the carbon cage through a nitrogen atom, has been investigated utilizing laser desorption/ionization mass spectrometry. investigating the formation of cationic and anionic C59N+/-, this approach is found to be a new and very efficient way to implement the initially exohedral nitrogen atom into the carbon cage. The laser-induced heterofullerene formation is discussed in terms of the structure and the charge state dependency of the target material. In further experiments, the coalescence reactivity, leading toward the formation of larger clusters has been examined following laser ablation of thin films of the (C59N)(2) dimer. Coalescence leads to two major reaction products, consisting of larger Cn-1N+ clusters which retain the nitrogen atom networked into a larger carbon cage and pure C-n(+) (n = even) carbon clusters, The Cn-1N+ cluster formation is accompanied by abundant metastable transitions caused by the loss of CN and the resulting implications for the coalescence mechanism are discussed. Finally, evidence is presented for the delayed electron emission of C59N .. The observation of delayed ionization of heterofullerenes is unprecedented, revealing a similar resistance toward fragmentation as in the case of their all-carbon fullerene analogues.