A family of lead clusters with precious metal cores

Abstract

Gold nanoparticles have been used for centuries, both for decoration and in medical applications. More recently, many of the major advances in cluster chemistry have involved welldefined clusters containing tens or hundreds of atoms, either with or without a ligand shell. In this paper we report the synthesis of two gold/lead clusters, [Au 8 Pb 33 ] 6− and [Au 12 Pb 44 ] 8− , both of which contain nido [Au@Pb 11 ] 3− icosahedra surrounding a core of Au atoms. Analogues of these large clusters are not found in the corresponding Ag chemistry: instead, the Ag-centered nido icosahedron, [Ag@Pb 11 ] 3− , is the only isolated product. The structural chemistry, along with the mass spectrometry which shows the existence of [Au 2 Pb 11 ] 2− but not [Ag 2 Pb 11 ] 2− , leads us to propose that the former species is the key intermediate in the growth of the larger clusters. Density functional theory indicates that secondary π-type interactions between the [Au@Pb 11 ] 3− ligands and the gold core play a significant part in stabilizing the larger clusters.

Ternary aromatic and anti-aromatic clusters derived from the hypho species [Sn2Sb5]3−

“…Recently, we adopted self-assembly as a synthetic strategy to synthesize a series of large Au/Pb clusters [Au 8 Pb 33 ] 6− , [Au 12 Pb 44 ] 8− , constructed from a nido -type cluster [AuPb 11 ] 3− 25 . As part of this ongoing study, we aim to build metal clusters using other unnoticed Zintl precursors and the solid-state Zintl phase “K 8 SnSb 4 ” came into our sight 26 .…”

Electronic structure and bonding in endohedral Zintl clusters

“…11) with a total electron count of 48 (= 4n + 4). 175 The structure shows the classic open face typical of this electron count and, although Cu and Au analogues have not been isolated, they have been proposed as intermediates in the growth of larger clusters such as [Cu 4 Pb 22 ] 4À , [Au 8 Pb 33 ] 6À and [Au 12 Pb 44 ] 8À . 175 A number of recent examples from the 12-vertex family with which we are primarily concerned in this review highlight the tendency to retain centrosymmetric geometries despite having electron counts that would be consistent with nido geometries.…”

[As3M(As3Pb3)]3− (M = Nb, Ta): Ternary Heterometallic Clusters with Early Transition Metal Atoms and Aromatic [Pb3]2−

“…[ 21 ] The average Pb‐Pb contacts are 3.2405 Å for 1 and 3.2347 Å for 2 , which are consistent with those in the lead clusters (Pb‐Pb: 3.247 Å (av) in [Au 12 Pb 44 ] 8− ). [ 12 ]…”

“…Although some unique lead and arsenic clusters have been reported, for example, icosahedral [M@Pb 12 ] 3− (M = Co, Rh, Ir), Pb 11 ‐based [Ag@Pb 11 ] 3− , [Au 8 Pb 33 ] 6− , [Au 12 Pb 44 ] 8− , [Cp*RuPb 11 ] 3− and [Cu@Cp*RuPb 11 ] 2− , derivatives of plumbaspherene [Cu 4 @Pb 18 ] 4− , onion‐like [As@Ni 12 @As 20 ] 3− , [Pd 7 As 16 ] 4− , [As 3 C 2 H 2 ] − , [Co(η 3 ‐As 3 ){η 4 ‐As 4 (mes) 2 }] 2− , Pb‐As hybridized system with transition metal elements have not been explored. [ 11‐18 ] In addition, there are only two examples of structurally characterized compounds with Pb‐As bonds, [PbAsSi i Pr 3 ] 6 and [(Me 3 Si) 3 SiAsPb] 4 , which can be searched in the Cambridge Crystallographic Data Center. [ 19,22 ] Our group previously reported a ternary cluster [As 3 Nb(As 3 Sn 3 )] 3− , which contains a Nb atom linked to an As 3 triangle and a bowl‐like As 3 Sn 3 .…”