12.4 Dependence on the Ionization Energy
209
Fig. 12.11 A Typical TOF mass spectra of copper cluster anions produced via the laser ablation
source (a) and after exposure to different quantity of NO gas with a partial pressure at 36 mPa
(b), 39 mPa (c) and 62 mPa (d) respectively. The numbers of atoms in copper cluster anions are
labelled on top of panel (a). B Kohn-sham energy level correlation between Cu
−
18 cluster with a
scalar relativistic Cu − (3d 10 4s 2 ), and a Cu 17 hollow cage at a removal of the interior copper atom
Cu
–
17–19 are inert even in the presence of sufficient reactants. While the stabilities of
Cu
–
17 and Cu
–
19 are due to their closed electronic shell structures, it is intriguing to
observe abnormal stability of an open-shell cluster Cu
–
18 . The ab initio calculations
revealed that Cu
–
18 bears a Cu@Cu
–
17 core-shell structure, and the unique electronic
configuration allows the unpaired SOMO electron to be mainly contributed by the
central copper atom (Fig. 12.11B); meanwhile the other 18 delocalized valence electrons occupy the lower-energy orbitals of the superatomic cluster. The unique electronic and geometric structures of Cu@Cu
–
17 result in a large HOMO-LUMO gap,
a large VDE value, as well as a large Cu-Cu binding energy but small NO-binding
energy; meanwhile, there is -1.06 |e| negative charge distributed on the interior copper
core, giving rise to tight electromagnetic shielding thus prohibiting electron transfer
from the Cu
–
18 cluster.
References
1. J. Sauer, B. Schroder, Angew. Chem. Int. Ed. 4, 711–714 (1965)
2. M. Ichikawa, M. Soma, T. Onishi, K. Tamaru, J. Phys. Chem. 70, 2069–2070 (1966)
3. M.S. Wrighton, H.B. Abrahamson, D.L. Morse, J. Am. Chem. Soc. 98, 4105–4109 (1976)
4. S.J. Formosinho, Molecular Photochemistry 8, 459–475 (1977)
5. H.B. Abrahamson, M.S. Wrighton, Inorg. Chem. 17, 3385–3388 (1978)
6. L.N. Domelsmith, P.D. Mollere, K.N. Houk, R.C. Hahn, R.P. Johnson, J. Am. Chem. Soc.
100, 2959–2965 (1978)
7. D. Ghesquiere, R. Arnaud, C. Caze, J. Phys. Chem. 83, 2029–2034 (1979)
8. G. Mauclaire, R. Derai, S. Fenistein, R. Marx, R. Johnsen, J. Chem. Phys. 70, 4023–4026
(1979)
9. K. Fujimori, N.A. Wickramasinghe, Aust. J. Chem. 33, 189–193 (1980)
10. J.S. Keute, D.R. Anderson, T.H. Koch, J. Am. Chem. Soc. 103, 5434–5439 (1981)
209
Fig. 12.11 A Typical TOF mass spectra of copper cluster anions produced via the laser ablation
source (a) and after exposure to different quantity of NO gas with a partial pressure at 36 mPa
(b), 39 mPa (c) and 62 mPa (d) respectively. The numbers of atoms in copper cluster anions are
labelled on top of panel (a). B Kohn-sham energy level correlation between Cu
−
18 cluster with a
scalar relativistic Cu − (3d 10 4s 2 ), and a Cu 17 hollow cage at a removal of the interior copper atom
Cu
–
17–19 are inert even in the presence of sufficient reactants. While the stabilities of
Cu
–
17 and Cu
–
19 are due to their closed electronic shell structures, it is intriguing to
observe abnormal stability of an open-shell cluster Cu
–
18 . The ab initio calculations
revealed that Cu
–
18 bears a Cu@Cu
–
17 core-shell structure, and the unique electronic
configuration allows the unpaired SOMO electron to be mainly contributed by the
central copper atom (Fig. 12.11B); meanwhile the other 18 delocalized valence electrons occupy the lower-energy orbitals of the superatomic cluster. The unique electronic and geometric structures of Cu@Cu
–
17 result in a large HOMO-LUMO gap,
a large VDE value, as well as a large Cu-Cu binding energy but small NO-binding
energy; meanwhile, there is -1.06 |e| negative charge distributed on the interior copper
core, giving rise to tight electromagnetic shielding thus prohibiting electron transfer
from the Cu
–
18 cluster.
References
1. J. Sauer, B. Schroder, Angew. Chem. Int. Ed. 4, 711–714 (1965)
2. M. Ichikawa, M. Soma, T. Onishi, K. Tamaru, J. Phys. Chem. 70, 2069–2070 (1966)
3. M.S. Wrighton, H.B. Abrahamson, D.L. Morse, J. Am. Chem. Soc. 98, 4105–4109 (1976)
4. S.J. Formosinho, Molecular Photochemistry 8, 459–475 (1977)
5. H.B. Abrahamson, M.S. Wrighton, Inorg. Chem. 17, 3385–3388 (1978)
6. L.N. Domelsmith, P.D. Mollere, K.N. Houk, R.C. Hahn, R.P. Johnson, J. Am. Chem. Soc.
100, 2959–2965 (1978)
7. D. Ghesquiere, R. Arnaud, C. Caze, J. Phys. Chem. 83, 2029–2034 (1979)
8. G. Mauclaire, R. Derai, S. Fenistein, R. Marx, R. Johnsen, J. Chem. Phys. 70, 4023–4026
(1979)
9. K. Fujimori, N.A. Wickramasinghe, Aust. J. Chem. 33, 189–193 (1980)
10. J.S. Keute, D.R. Anderson, T.H. Koch, J. Am. Chem. Soc. 103, 5434–5439 (1981)