J. Mass Spectrom. Soc. Jpn.

Vol. 57, No. 6, 2009

COMMENTARY  2  

Fundamentals of Mass Spectrometry
῍Superexcited States of Molecules῍Noriyuki KDJ8=>   Department of Chemistry, Tokyo Institute of Technology,

Meguro-ku, TOKYO, JAPAN
Superexcited states of molecules are defined as neutral excited states that have energies higher than the firstionization energy. They are much different from ordinary excited states of which energies are below the firstionization energy. The characteristics and dynamics of the superexcited states are discussed to substantiate thatthe molecule obtaining energy higher than the first ionization energy does not always ionize.
(Received May 25, 2009; Accepted May 25, 2009)

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10 ABC'D! EFG *+ (1996), p. 124.
5) ,-./ 0 ;<ῌ452367 14! 4589 *+ (2007), p. 37, p. 192.
6) HIJK LMN O  73, 32 (2002).
7) LMN O HIJK "#23$P 61, 671 (2006).
8) Y. Hatano, Phys. Reports, 313, 109 (1999).

ῌ    ! "#$% $&'() *+ (2006), p. 225.
2) H. Nakamura, Int. Rev. Phys. Chem., 10, 123 (1991).
3) ,-./ 0 1 23ῌ452367 11! 458
9 *+ (2000), p. 393.
4) ,-./ :0 :1 ;<ῌ=23>?@1)

Keywords: Superexcited states, Ionization energy, Autoionization, Neutral dissociation, Photoionization quantum yieldῌ 391 ῌ