Formation of binary alloy cluster ions from group‐14 elements and cobalt and comparison with solid‐state alloys

Abstract

By using laser ablation on mixtures of transition metal cobalt and group-14 elements, binary alloy cluster anions were produced while no binary alloy cluster cations were detected, and the homocluster cations of group-14 elements appeared at very low abundance. The differences between clustering abilities of germanium, tin and lead with cobalt are described, and the chemical bonds in the binary alloy cluster anions appear to indicate a transition from covalent to metal bonds. The cluster anion [CoPb10](-) appears in very high abundance (magic number), and an endohedral structure is proposed for this cluster. The cluster anion [CoPb12](-), also representing a magic number, probably has an icosahedral structure. Compared with solid-state Co/Ge binary alloys, the compositions of most binary alloy cluster anions are germanium-rich, in which the covalent bonds are predominant.

Magic bimetallic cluster anions of M/Pb (M = Au, Ag and Cu) observed and analyzed by laser ablation and time‐of‐flight mass spectrometry

“…In both cases, the binary clusters containing 1, 2 and 3 coinage metal atoms were observed. Similarly to what was observed in our earlier work,17,18 Pb n − and [MPb n ] − were two dominant product series. However, the new species such as [Cu 3 Pb n ] − and [Ag m Pb n ] − (m = 2, 3) can only be distinguished using this high‐resolution mass spectrometer.…”

“…For example Pb 5 2− can be regarded as a stable Zintl ion, and therefore the presence of less electronegative and single valence atoms M has the tendency to form {[Pb 5 ] 2− M + } cluster structures 20. As for [MPb 10 ] − and [MPb 12 ] − , based on the bi‐capped square antiprism structure of Pb 10 and the icosahedron structure of Pb 13 ,12,13 the lead packing cage structures with one transition metal inside was proposed 17. However, the magic clusters observed in the [M 2 Pb n ] − and [M 3 Pb n ] − series are difficult to explain based only on this geometrical picture 18…”

“…The stability of magic cluster species of lead (containing 7, 13 and 19 atoms) has been explained assuming the closed polyhedron structures 12,13. In our earlier studies,17,18 similar structures were also used to explain the magic cluster species in M/Pb binary clusters containing one or two transition metals M (M = Co, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Pd, Ag, etc.). However, the magic cluster species present in the Pb n 2+ system (n = 9, 15, 23, 27, 35) satisfy exactly the closed electron shells criterion 16…”

Formation, growth mechanism and packing sequences of binary alloy cluster anions from laser ablation of mixtures of lead and transition metals

“…In our previous publications, the compositions and distributions of Co/Pb binary alloy clusters were reported in detail 13. Here we report the study of M/Pb magic clusters, and the mechanism of cluster growth and packing sequences.…”

Endohedrale Zintl‐Ionen: intermetalloide Cluster

“…Während heteroatomare Cluster aus Elementen der Gruppe 14 und Alkalimetallen in der Gasphase schon länger bekannt sind,29, 30 wurden Hauptgruppenelement/Übergangsmetall‐Cluster in Gasphasenexperimenten bisher kaum untersucht 31. Die in der Gasphase sehr stabilen Dimetallcluster [AlPb 10 ] + und [AlPb 12 ] + haben nach theoretischen Untersuchungen Strukturen mit D 4d ‐ bzw.…”