Cluster Growth and Fragmentation in the Highly Fluxional Platinum Derivatives of Sn₉^4-:  Synthesis, Characterization, and Solution Dynamics of Pt₂@Sn₁₇^4- and Pt@Sn₉H^3-

Abstract

Sn94- reacts with Pt(PPh3)4 in ethylenediamine/toluene solvent mixtures in the presence of 2,2,2-cryptand to give four different complexes: "Rudolph's complex" of proposed formula [Sn9Pt(PPh3)x]4- (2), the previously reported [Pt@Sn9Pt(PPh3)]2- ion (3), and the title complexes Pt2@Sn174- (4) and Pt@Sn9H3- (5). The use of Pt(norbornene)3 instead of Pt(PPh3)4 gives complex 4 exclusively. The structure of 4 contains two Pt atoms centered in a capsule-shaped Sn17 cage. The complex is highly dynamic in solution showing single, mutually coupled 119Sn and 195Pt NMR resonances indicative of an intramolecular liquidlike dynamic exchange process. Complex 5 has been characterized by selectively decoupled 1H, 119Sn, and 195Pt NMR experiments and shows similar liquidlike fluxionality. In addition, the H atom scrambles across the cage showing small couplings to both Sn and Pt atoms. Neither 3 nor 4 obeys Wades rules; they adopt structures more akin to the subunits in alloys such as PtSn4. The structural and chemical relevance to supported PtSn4 heterogeneous catalysts is discussed.

[Zn6Sn3Bi8]4−: Erweiterung des Konzepts intermetalloider Zintl‐ Anionen auf ternäre Systeme

“…[6] Aktuelle Beispiele von Käfigen mit Elementen der Gruppe 13 (Triele), 14 , [7] [Cu@E 9 ] 3À (E = Sn, Pb), [8] [Pt 2 @Sn 17 ] 4À , [9] [Pd 2 @E 18 ] 4À (E = Ge, Sn), [10] [Ni(Ni@Ge 9 ) 2 ] 4À , [11a] [Zn 9 Bi 11 ] 5À , [11b] [Ni 5 Sb 17 ]…”

“…vier Elektronen bei, sodass mit insgesamt 43 Elektronen fünf weniger vorhanden wären als erwartet. Wie für [Zn 9 Bi 11 ] 5À werden die Wade-Mingos-Regeln jedoch erfüllt, wenn man die fünf externen Bi-Liganden als Ein-Elektron-Donoren rechnet; da diese Liganden nicht Bestandteil des Deltaeders sind, müssen sie nicht notwendigerweise als Drei-ElektronenDonoren fungieren. Populationsanalysen -sowohl NPA als auch Mulliken-Analysen…”

Polyhedral nine-atom clusters of tetrel elements and intermetalloid derivatives

“…the formation of a cluster species that includes two transition metals and 18 tetrel atoms (see figure 10d) (Kesanli et al 2007). …”

Chemistry with Bare Silicon Clusters in Solution: A Transition‐Metal Complex of a Polysilicide Anion

“…(M = Fe, Co), [13] [Pt 2 @Sn 17 ] 4À , [14] and [Pd 2 @Ge 18 ] 4À . [15] It is evident that a future combination of both preparative trends, that is, the oxidative coupling of endohedral clusters, would offer a totally new route to cluster-assembled nanomaterials based on Group 14 elements.…”