LASER STUDY ON THE RESONANCE-ENHANCED MULTIPHOTON ELECTRON DETACHMENT(REMPED) PROCESSES FOR C-60(-) AND C-70(-)

The resonance-enhanced multiphoton electron detachment (REMPED) spectr a for C-60(-) and C-70(-) have been obtained. They are regarded as the absorption spectra for these fullerene anions in the gas phase. The R EMPED spectrum of a fragment anion produced in the fragmentation proce ss of C-70(-), having a mass of 720, has been measured. This spectrum shows a threshold identical to that of C-60(-) at ca. 8200 cm(-1). Thu s the fragment anion is assigned to C-60(-) With the icosahedral struc ture. The REMPED spectrum of C-70(-) shows a broad band in the near-in frared region. The nature of the appearance of this band is discussed in consideration of the ground electronic state for C-70(-).