Yatsuhashi Tomoyuki, Nakashima Nobuaki
Department of Chemistry, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi, Osaka 558-8585 Japan.
J Phys Chem A. 2008 Jul 3;112(26):5781-5. doi: 10.1021/jp8023028. Epub 2008 Jun 11.
Desorption of C 60 (+) and its dimer cation was investigated on irradiation with nonresonant femtosecond laser pulses at 1.4 mum. Ionization of solid C 60 revealed strikingly different features, such as the absence of multiply charged molecular ions, the emission of C (+) at low laser intensity, C 2 attachments, delayed ionization, and dimer cation formation, as compared with the gas phase experiments. The large kinetic energy distribution of ions found in this study indicated that the desorption process was mainly driven by an electrostatic mechanism rather than by thermal, photochemical, or volume expansion mechanisms. Singly charged C 60 emission by a Coulomb explosion due to the high density of C 60 (+) is suggested.
研究了在1.4μm非共振飞秒激光脉冲辐照下C60(+)及其二聚体阳离子的解吸情况。与气相实验相比,固态C60的电离显示出显著不同的特征,如不存在多电荷分子离子、在低激光强度下发射C(+)、C2附着、延迟电离和二聚体阳离子形成。本研究中发现的离子的大动能分布表明,解吸过程主要由静电机制驱动,而非热、光化学或体积膨胀机制。有人提出,由于C60(+)的高密度,通过库仑爆炸产生单电荷C60发射。