4
1 An Overview of Metal Clusters and Their Reactivity
alkali metal and coinage metal clusters offer relative simplicity as they are hydrogenlike and each bears a valence electron (s
1 ). Coinage metals typically have fully occupied d-orbital while half-filled s-orbitals, rendering a variety of tuneable metal-metal
and metal-nonmetal bonding patterns. Extensive interest has also been devoted to
the PES studies of metal clusters pertaining to both theoretical and experimental
aspects [119–133]. Meanwhile, several other spectroscopies, including the VUV +
IR two-color photoionization spectroscopy [134], infrared multiphoton dissociation
(IRMPD) action spectroscopy [35, 135–146], are available for the identification of
metal cluster structure. The IR experimental results are verified by theoretical calculation results, shedding light on the structure chemistry of gas-phase metal clusters within jellium model, under superatom characteristics [105, 147], and crystalfield-like splitting of orbitals [148, 149], and likely relativistic effect being involved
[150].
This book surveys the advances that have emerged from investigations of metal
cluster reactivity using mass spectrometry. Our focus is first directed toward the
metal cluster reactions relating to etching effect, oxidation/reduction, halogenation, hydrogen evolution reactions (HER) and energetic reaction with hydrocarbons, collision-induced dissociation (CID) [151–158], photodissociation [159–
163], cluster-size dependence and charge-state variation, charge-transfer dependence
[164], shedding light on the odd-even alternation effect (or, spin effect) [149, 165–
167], complementary-active-sites (CAS) [168] mechanisms, and the harpoon mechanism [169]. Continuing with the cluster reactivity surrounding with metallocarbohedrenes (Met-Cars) [170–172], some interesting aspects such as cluster catalysis
and cluster-assembly materials are also summarized. Also involved, are correlative
theoretical investigations based on the first-principles calculations which have been
applied to depict the reaction coordinates [173]. Advances in cluster science have
also stimulated interest in exploring superatoms and superatom complexes [101–
103], shedding light on the stability and reactivity of both naked metal clusters
[116], and ligand-protected metal nanoclusters [34, 36, 66, 174–187], enabling to
prepare new materials with the characteristics of cluster genes being inherited [68].
References
1. A.W. Castleman Jr., R.G. Keesee, Acc. Chem. Res. 19, 413–419 (1986)
2. S.N. Khanna, A.W. Castleman Jr., Quantum Phenomena in Clusters and Nanostructures
(Springer, New York, 2003)
3. A.W. Castleman Jr., Environ. Sci. Technol. 22, 1265–1267 (1988)
4. A.W. Castleman Jr., P. Jena, Proc. Natl. Acad. Sci. U. S. A. 103, 10554–10559 (2006)
5. S.A. Claridge, A.W. Castleman, S.N. Khanna, C.B. Murray, A. Sen, P.S. Weiss, ACS Nano
3, 244–255 (2009)
6. A.W. Castleman, Catal. Lett. 141, 1243–1253 (2011)
7. P. Jena, S. Behera, Clusters and Nanostructured Materials (Nova Scientific Publishers, New
York, 1996)
8. K.A. Zemski, D.R. Justes, A.W. Castleman Jr., J. Phys. Chem. B 106, 6136–6148 (2002)
9. A.W. Castleman Jr., S.N. Khanna, J. Phys. Chem. C 113, 2664–2675 (2009)
1 An Overview of Metal Clusters and Their Reactivity
alkali metal and coinage metal clusters offer relative simplicity as they are hydrogenlike and each bears a valence electron (s
1 ). Coinage metals typically have fully occupied d-orbital while half-filled s-orbitals, rendering a variety of tuneable metal-metal
and metal-nonmetal bonding patterns. Extensive interest has also been devoted to
the PES studies of metal clusters pertaining to both theoretical and experimental
aspects [119–133]. Meanwhile, several other spectroscopies, including the VUV +
IR two-color photoionization spectroscopy [134], infrared multiphoton dissociation
(IRMPD) action spectroscopy [35, 135–146], are available for the identification of
metal cluster structure. The IR experimental results are verified by theoretical calculation results, shedding light on the structure chemistry of gas-phase metal clusters within jellium model, under superatom characteristics [105, 147], and crystalfield-like splitting of orbitals [148, 149], and likely relativistic effect being involved
[150].
This book surveys the advances that have emerged from investigations of metal
cluster reactivity using mass spectrometry. Our focus is first directed toward the
metal cluster reactions relating to etching effect, oxidation/reduction, halogenation, hydrogen evolution reactions (HER) and energetic reaction with hydrocarbons, collision-induced dissociation (CID) [151–158], photodissociation [159–
163], cluster-size dependence and charge-state variation, charge-transfer dependence
[164], shedding light on the odd-even alternation effect (or, spin effect) [149, 165–
167], complementary-active-sites (CAS) [168] mechanisms, and the harpoon mechanism [169]. Continuing with the cluster reactivity surrounding with metallocarbohedrenes (Met-Cars) [170–172], some interesting aspects such as cluster catalysis
and cluster-assembly materials are also summarized. Also involved, are correlative
theoretical investigations based on the first-principles calculations which have been
applied to depict the reaction coordinates [173]. Advances in cluster science have
also stimulated interest in exploring superatoms and superatom complexes [101–
103], shedding light on the stability and reactivity of both naked metal clusters
[116], and ligand-protected metal nanoclusters [34, 36, 66, 174–187], enabling to
prepare new materials with the characteristics of cluster genes being inherited [68].
References
1. A.W. Castleman Jr., R.G. Keesee, Acc. Chem. Res. 19, 413–419 (1986)
2. S.N. Khanna, A.W. Castleman Jr., Quantum Phenomena in Clusters and Nanostructures
(Springer, New York, 2003)
3. A.W. Castleman Jr., Environ. Sci. Technol. 22, 1265–1267 (1988)
4. A.W. Castleman Jr., P. Jena, Proc. Natl. Acad. Sci. U. S. A. 103, 10554–10559 (2006)
5. S.A. Claridge, A.W. Castleman, S.N. Khanna, C.B. Murray, A. Sen, P.S. Weiss, ACS Nano
3, 244–255 (2009)
6. A.W. Castleman, Catal. Lett. 141, 1243–1253 (2011)
7. P. Jena, S. Behera, Clusters and Nanostructured Materials (Nova Scientific Publishers, New
York, 1996)
8. K.A. Zemski, D.R. Justes, A.W. Castleman Jr., J. Phys. Chem. B 106, 6136–6148 (2002)
9. A.W. Castleman Jr., S.N. Khanna, J. Phys. Chem. C 113, 2664–2675 (2009)