DIODE LASER SPECTROSCOPY OF CLUSTERS PRODUCED BY THE PICK-UP METHOD

用分子动力学方法模拟了具有不同形状异构体的Ar团簇的振动运动。结果表明，在近球形异构体中，只有呼吸振动被激发，而在非球形异构体中，四重球状振动被显著激发。四重球面振动的激发与同分异构体的球度密切相关。另一方面，当激发非球形Ar&lt；30&gt；时，在光谱中观察到三个很强的峰。用质谱学方法研究了Ar团簇与CO2分子通过拾取方法碰撞时的分子交换反应。在分子交换反应中产生了二元团簇Ar_mCO_2。测量的反应截面和反应中Ar原子的平均释放数与分子动力学方法计算的结果基本一致。用质谱学方法研究了(CO2)n团簇与CH3OH通过拾取方法发生的分子交换反应。用半导体激光器组装了一台测量二聚体振转光谱的装置，并测量了(CO2)2的振转光谱。当引入CH_3OH时，吸收峰消失，表明(CO_2)_2被拾取方法衰减。

The vibrational motion of Ar clusters having isomers in a variety of shapes was simulated by the molecular dynamics method. It was found that only the breathing vibration was excited in nearly spherical isomers, while signifin cant excitation of the quadruple spheroidal vibration was observed in non-spherical isomers. The excitation of the quadruple spheroidal vibration was found to be closely related to the degrees of sphericality fo the isomers. On the other hand, when a non-spherical Ar_<30> was excited, three strong peaks were observed in the spectra. One of the three peaks was assigned to the bending vibration of the cluster in whole.Molecular exchange reaction of an argon cluster, in collision with a CO_2 molecule by pick-up method was investigated by mass spectrometry. Binary clusters, Ar_mCO_2, were found to be produced in the molecular exchange reaction. The measured reaction cross section and the average numbers of release Ar atoms in the reaction were almost consistent with those calculated by the molecular dynamics method.Molecular exchange reaction of (CO_2)_n cluster, in collision with CH_3OH by pick-up method was investigated by mass spectrometry. An apparatus for measurement of vibration-rotation spectra of dimers was assembled with a diode laser and the vibration-rotation spectrum of (CO_2)_2 was measured. Peaks of the spectrum was found to disappear when CH_3OH was introduced, indicating that (CO_2)_2 was attenuated by the pick-up method.