Vibrational cooling in a cold ion trap:: Vibrationally resolved photoelectron spectroscopy of cold C-60 anions -: art. no. 051106

We demonstrate vibrational cooling of anions via collisions with a background gas in an ion trap attached to a cryogenically controlled cold head (10-400 K). Photoelectron spectra of vibrationally cold C-60(-) anions, produced by electrospray ionization and cooled in the cold ion trap, have been obtained. Relative to spectra taken at room temperature, vibrational hot bands are completely eliminated, yielding well-resolved vibrational structures and a more accurate electron affinity for neutral C-60. The electron affinity of C-60 is measured to be 2.683 +/- 0.008 eV. The cold spectra reveal complicated vibrational structures for the transition to the C-60 ground state due to the Jahn-Teller effect in the ground state of C-60(-). Vibrational excitations in the two A(g) modes and eight H-g modes are observed, providing ideal data to assess the vibronic couplings in C-60(-) (C) 2005 American Institute of Physics.