Synthesis and characterization of the paramagnetic [Ag13Fe8(CO)32]4- tetraanion: a cuboctahedral Ag13 cluster stabilized by Fe(CO)4 groups behaving as 4-electron donors

[Ag21{S2P(OiPr)2}12]+: An Eight‐Electron Superatom

“…This structure consists of a centered icosahedron Ag 13 core that is further capped by eight silver atoms and stabilized by 12 dithiophosphate ligands (dtp; {S 2 P(O i Pr) 2 } − ). To the best of our knowledge, the core unit of this nanocluster is the first example of silver‐centered Ag 12 icosahedron,17 even though a metal‐centered icosahedron is known with other noble metals, such as palladium18 and gold,19, 7c and more importantly embedding a silver atom inside an icosahedron Ag 12 shell has been a topical project in contemporary theoretical calculations 20…”

Molecular Magnetic Quantum Dots in Multivalent Metal Cluster Compounds

“…In both cases the hyperfine splitting of the ESR line is due to the interaction of the unpaired elec- tron spin with the nuclear spins of Pt and Ag, respectively [6,8] (isotope 57 Fe features a nuclear spin, but with only 2% abundance, it cannot be detected). The ESR spectra thus point to a substantial amount of spin density at the nonmagnetic metal sites, in good agreement with the calculated spin density maps presented below.…”

“…1 [6][7][8][9]. Depending on the valency, these materials are either nonmagnetic or carry an unpaired spin 1 2 on each cluster molecule.…”

“…In the Pt 3 Fe 3 cluster, about 18% population of the spin density is localized on the 3 Pt atoms and about 70% on the 3 Fe atoms, confirming that the magnetism is not carried by electrons in localized (Fe) atomic orbitals, but in delocalized cluster molecular orbitals. For the Ag 13 Fe 8 cluster, the ESR data [8] showed that 25% of the spin density is located on the central Ag atom, whereas the 12 peripheral Ag atoms carry negligible spin ͑Ӎ1%͒. This would imply an even larger spin density on the central Ag atom than on each of the Fe atoms ͑Ӎ10%͒.…”

[{Ag(tBuNH2)2}4][{Ag(tBuNH2)(tBuN=CHCH3)}2][Ag12(CF3CO2)14] – eine Verbindung mit einem Ag128+-Clusterkern

“…[9] Alle drei Polyeder können als Ausschnitte einer kubisch dichtesten Packung von Metallatomen aufgefasst werden. Ein weiteres Beispiel für einen subvalenten Münzmetallcluster ist die Verbindung [Ag 13 Fe 8 -(CO) 32 ] 4À ; [10] auch die von Teo et al synthetisierten Ag/Au-Dimetallcluster [11] können dieser Substanzklasse zugerechnet werden.…”