1. A Molecular Carbonyl Metal Cluster CO ligand shell A Spherical Capacitor Metal core

2. To be truly assimilable to a molecular capacitor a CO-stabilized cluster should fulfill a few conditions: 1. the CO ligand shell should insulate the metal core 2. the metal cluster should have electron-sink behaviour (be multivalent or, at least, display redox behaviour) 3. the “metal” core of the cluster should undergo transition from insulator-to-metal or be, at least, in a semiconductor regime

3. [Ni 32 C 6 (  -CO) 36 ] 6-

4. Frontier region and CV profile of [Ni 32 C 6 (CO) 36 ] 6- 6-/7- 7-/8- 8-/9- 9-/10- 5-/6-  E av = 0.28 V DFT: 7 almost degenerate MOs containing 10 electrons.

5. CV and DPV of C 60 Q. Xie, E. Perez-Cordero, L. Echegoyen, J. Am. Chem. Soc., 1992, 114, 3977  E av = 0.45 V

6. STM Coulomb staircase, CV and DPV of alkanethiolate Au 146 cluster R. L. Whetten et al., J. Am. Chem. Soc., 1997, 119, 9279  E av = ca. 0.4 V

7. 1- [Ni 11 Sb 2 (CO) 18 ] n- ; 2-[Ni 11 Bi 2 (CO) 18 ] n- ; 3-[Ni 13 Sb 2 (CO) 24 ] n- ; 4- [Rh 14 (CO) 25 ] n- ; 5- [Ni 5 Rh 9 (CO) 25 ] n- ; 6- [Pt 19 (CO) 22 ] n- ; 7- [Pt 24 (CO) 30 ] n- ; 8- [Ni 32 C 6 (CO) 36 ] n- ; 9- [HNi 38 C 6 (CO) 42 ] n- ; 10- [Ni 38 C 6 (CO) 42 ] n- ; 11- [HNi 36 Pt 4 (CO) 45 ] n- ; 12- [Ni 36 Pt 4 (CO) 45 ] n- ; 13- [Ni 38 Pt 6 (CO) 48 ] n- ; 14-[HNi 38 Pt 6 (CO) 48 ] n-. Experimental Proof of the Size-induced Insulator-Metal Transition of the Metallic Kernel of a Metal Carbonyl Cluster

8. Carbonyl Metal Clusters do behave as Molecular Capacitors: CO shell Metal core 5-/6-/7-/8-/9-/10- 1. The CO shell insulates the metal core 2. The cluster behaves as an electron sink 3. The electrons are injected or ejected one by one, each at a specific potential 4. The potentials can be tuned (hydride, surface colouring, change of intersttial metal atoms, etc.) 5. The metal core undergoes metallisation as a function of nuclearity 6. The dimensions trespass from the bottom in the nano field n e -

9. Magnetic Properties of Odd-electron Carbonyl Metal Clusters: e.g. [Fe 3 Pt 3 (CO) 15 ] - L.J. De Jongh et al., Phys. Rev. Lett., 1998, 81, 3211; J. Sinzig, Ph.D. Thesis, Leiden,1997

10. On the Way Towards Metallization of the Cluster Metal Core. Magnetic Properties of Even-electron Carbonyl Metal Clusters? [Ni 16 Pd 16 (CO) 40 ] 4- 17 MOs [Ni 32 Pt 24 (CO) 56 ] 6- 30 MOs All within –11 and –9.5 eV. Some MOs are almost degenerate.