Size-selective formation of C78 fullerene from a three-dimensional polyyne precursor.
Multicyclic cagelike cyclophanes 2 a and 2 b containing cyclobutene rings have been prepared as precursors of three-dimensional polyynes C78H18 (1a) and C78H12Cl6 (1b), respectively. Laser irradiation of 2a and 2b induced expulsion of the aromatic fragment, indane, to give the three-dimensional polyyne anions C78H18- and C78H12Cl6-, respectively. Whereas the former anion lost only four hydrogen atoms to form C78H14-, complete loss of all hydrogen and chlorine atoms was observed from the latter anion, to yield a C78- ion that has a fullerene structure which was proven by its characteristic fragmentation pattern.
Tobe
Yoshito
Y
Division of Frontier Materials Science, Graduate School of Engineering Science, Osaka University, and CREST (JST), 1-3 Machikaneyama, Toyonaka 560-8531, Japan. tobe@chem.es.osaka-u.ac.jp
Umeda
Rui
R
Sonoda
Motohiro
M
Wakabayashi
Tomonari
T