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The reduction of (nBu3P)AgCl with LiBH(sBu)3 in toluene gives the metalloid silver cluster Ag64(PnBu3)16Cl6 (1) as dark red, temperature‐ and light‐sensitive single crystals in high yield. 1 is the largest structurally characterized metalloid silver cluster exhibiting chlorine and phosphine substituents only. The silver atoms in 1 show an overall brick‐shape arrangement, where structural resemblance to the close‐packed fcc and hcp structures is realized. Within 1 a 58 electron closed shell system is present. The light sensitivity renders 1 as a model compound for the primary seeds of the photo process, whereby this sensitivity, together with the high‐yield synthesis show that 1 is a perfect starting compound for further investigations like silver‐plating processes. [ABSTRACT FROM AUTHOR]

The reduction of (nBu3P)AgCl with LiBH(sBu)3 in toluene gives the metalloid silver cluster Ag64(PnBu3)16Cl6 (1) as dark red, temperature‐ and light‐sensitive single crystals in high yield. 1 is the largest structurally characterized metalloid silver cluster exhibiting chlorine and phosphine substituents only. The silver atoms in 1 show an overall brick‐shape arrangement, where structural resemblance to the close‐packed fcc and hcp structures is realized. Within 1 a 58 electron closed shell system is present. The light sensitivity renders 1 as a model compound for the primary seeds of the photo process, whereby this sensitivity, together with the high‐yield synthesis show that 1 is a perfect starting compound for further investigations like silver‐plating processes. [ABSTRACT FROM AUTHOR]

Three multi‐shell metalloid gold clusters of the composition Au32(R3P)12Cl8 (R=Et, nPr, nBu) were synthesized in a straightforward fashion by reducing R3PAuCl with NaBH4 in ethanol. The Au32 core comprises two shells, with the inner one constituting a tilted icosahedron and the outer one showing a distorted dodecahedral arrangement. The outer shell is completed by eight chloride atoms and twelve R3P groups. The inner icosahedron shows bond lengths typical for elemental gold while the distances of the gold atoms in the dodecahedral arrangement are in the region of aurophilic interactions. Quantum‐chemical calculations illustrate that the Jahn–Teller effect observed within the cluster core can be attributed to the electronic shell filling. The easily reproducible synthesis, good solubility, and high yields of these clusters render them perfect starting points for further research. Gold cluster triumvirate: Three gold clusters Au32(R3P)12Cl8 were synthesized, obtained in good yields in crystalline form, and structurally characterized. They show the same Jahn–Teller‐distorted core motif consisting of an Au12 icosahedron inside an Au20 dodecahedron, and differ only in the length of the alkyl chains of the respective phosphine ligands and their solubility properties. [ABSTRACT FROM AUTHOR]

The reduction of (Ph3P)AuCl with NaBH4 in the presence of HSC(SiMe3)3, leads to one of the largest metalloid gold clusters: Au108S24(PPh3)16 ( 1). Within 1 an octahedral Au44 core of gold atoms arranged as in Au metal is surrounded by 48 oxidized Au atoms of an Au48S24 shell, a novel building block in gold chemistry. The protecting Au48S24 shell is completed by additional 16 Au(PPh3) units, leading to a complete protection of the gold core. Within 1 the Au-Au distances get more molecular on going from the center to the ligand shell. Cluster 1 represents novel structural motives in the field of metalloid gold clusters which also are partly typical for metal atoms in metalloid clusters: M nR m ( n> m). [ABSTRACT FROM AUTHOR]

Recently the metalloid cluster compound [Ge9Hyp3]− ( 1; Hyp=Si(SiMe3)3) was oxidatively coupled by an iron(II) salt to give the largest metalloid Group 14 cluster [Ge18Hyp6]. Such redox chemistry is also possible with different transition metal (TM) salts TM2+ (TM=Fe, Co, Ni) to give the TM+ complexes [Fe(dppe)2][Ge9Hyp3] ( 3; dppe=1,2-bis(diphenylphosphino)ethane), [Co(dppe)2][Ge9Hyp3] ( 4), [Ni(dppe)(Ge9Hyp3)] ( 5) and [Ni(dppe)2(Ge9Hyp3)]+ ( 6). Such a redox reaction does not proceed for Mn, for which a salt metathesis gives the first open shell [Hyp3Ge9-M-Ge9Hyp3] cluster ( 2; M=Mn). The bonding of the transition metal atom to 1 is also possible for Ni (e.g., compound 6), in which one or even two nickel atoms can bind to 1. In contrast to this in case of the Fe and Co compounds 3 and 4, respectively, the transition-metal atom is not bound to the Ge9 core of 1. The synthesis and the experimentally determined structures of 2- 6 are presented. Additionally the bonding within 2- 6 is analyzed and discussed with the aid of EPR measurements and quantum chemical calculations. [ABSTRACT FROM AUTHOR]

The increasing number of metalloid clusters, synthesized in the last couple of years, gives new insights into the formation process of metals or semi-metals. Metalloid clusters of the transition metals, especially the coinage metals are thereby of particular interest and the number of structurally characterized metalloid gold clusters has increased over the last decade. Most of these clusters are stabilized via aryl thiolate ligands. Herein, the synthesis and crystal structures of the lithium and potassium salts of the bulky SSi(SiMe3)3 ligand are presented together with the synthesis of suitable MI precursors ( M = Cu, Ag, Au) for further build-up reactions to metalloid clusters. [ABSTRACT FROM AUTHOR]

The oxidation of [Ge9(Hyp)3]− (Hyp=Si(SiMe3)3) with an FeII salt leads to Ge18(Hyp)6 ( 1), the largest Group 14 metalloid cluster that has been structurally characterized to date. The arrangement of the 18 germanium atoms in 1 shows similarities to that found in the solid-state structure Ge(cF136). Furthermore, 1 can be described as a macropolyhedral cluster of two Ge9 units. Quantum-chemical calculations further hint at a strained arrangement so that 1 can be considered as a first trapped intermediate on the way from Ge9 units to elemental germanium with the clathrate-II structure (Ge(cF136)). [ABSTRACT FROM AUTHOR]

Chemistry that uses metalloid tin clusters as a starting material is of fundamental interest towards understanding the reactivity of such compounds. Since we identified {Sn10[Si(SiMe3)3]4}2− 7 as an ideal candidate for such reactions, we present a further step in the understanding of metalloid tin cluster chemistry. In contrast to germanium chemistry, ligand elimination seems to be a major reaction channel, which leads to the more open metalloid cluster {Sn10[Si(SiMe3)3]3}− 9, in which the Sn core is only shielded by three Si(SiMe3)3 ligands. Compound 9 is obtained through different routes and is crystallised together with two different countercations. Besides the structural characterisation of this novel metalloid tin cluster, the electronic structure is analysed by 119Sn Mössbauer spectroscopy. Additionally, possible reaction pathways are discussed. The presented first step into the chemistry of metalloid tin clusters thus indicates that, with respect to metalloid germanium clusters, more reaction channels are accessible, thereby leading to a more complex reaction system. [ABSTRACT FROM AUTHOR]

The reaction of a SnICl solution with LiSi(SiMe3)3 gave the anionic metalloid tin cluster {Sn10[Si(SiMe3)3]4}2− ( 7) in good yield. The arrangement of the ten tin atoms in the cluster core can be described as a distorted centaur polyhedron. Quantum chemical calculations suggest that there are 26 bonding electrons in the cluster core, which may be described as an arachno cluster in agreement with Wade's rules. NMR and mass spectrometric investigations showed that 7 is highly reactive, which may be due to the open ligand shell. The easily available tin atoms in 7 thereby open the door to further subsequent reactions, in which 7 may act as a building block to larger cluster aggregates. [ABSTRACT FROM AUTHOR]

Metalloid cluster compounds of tin of the general formulae SnnRm with n>m (R=organic ligand), where beside ligand-bound tin atoms also 'naked' tin atoms, that only bind to other tin atoms, are present, represent a novel class of cluster compounds in tin chemistry. As the 'naked' tin atoms inside these clusters exhibit an oxidation state of 0, the average oxidation state of the tin atoms within such metalloid tin clusters is in between 0 and 1. Thus, these cluster compounds may be seen as intermediates on the way to the elemental state. Therefore, interesting properties are expected for these compounds, which might complement results from nanotechnology. During the last years, different syntheses of such novel cluster compounds have been introduced, leading to several metalloid tin cluster compounds, which exhibit new and partly unusual structure and bonding properties. In this review, recent results in this novel field of group 14 chemistry are discussed, whereby special attention is focused on the novel synthetic route applying a disproportionation reaction of metastable Sn(I) halides. [ABSTRACT FROM AUTHOR]

Abstract: Metalloid cluster compounds are ideal model compounds for the area between the molecular and solid state, i.e. the nanometer regime. For the synthesis of metalloid cluster compounds, the disproportionation reaction of a metastable subhalide is a fruitful synthetic route. In the case of tin, monohalides are needed for this synthetic route as tin(II) halides are too stable to be used. Due to thermodynamic data, gaseous SnBr should be formed at 1370°C, and by applying a co-condensation technique it can be trapped at −196°C and prepared in synthetic scale. Herein first analyses of SnBr are presented, showing that SnBr is more reactive than the corresponding GeBr, already disproportionating quantitatively to elemental tin and SnBr2 on heating to room temperature. By applying nitrogen-based donor molecules like NnBu3 or pyridine, the reactivity can be moderated and the solubility is enhanced leading e.g. to an SnBr emulsion, which can be used for the synthesis of metalloid cluster compounds of tin. [Copyright &y& Elsevier]

The most fruitful synthetic route to metalloid tin clusters applies the disproportionation reaction of metastable Sn(I) halide solutions, whereby Si(SiMe3)3 is mostly used as the stabilizing substituent. Here, we describe the synthesis and application of the slightly modified substituent Ge(SiMe3)3, which can be used for the synthesis of metalloid tin clusters to give the neutral cluster Sn10[Ge(SiMe3)3]6 as well as the charged clusters {Sn10[Ge(SiMe3)3]5}− and {Sn10[Ge(SiMe3)3]4}2−. The obtained metalloid clusters are structurally similar to their Si(SiMe3)3 derivatives. However, differences with respect to the stability in solution are observed. Additionally, a different electronic situation for the tin atoms is realized as shown by 119mSn Mössbauer spectroscopy, giving further insight into the different kinds of tin atoms within the metalloid cluster {Sn10[Ge(SiMe3)3]4}2−. The synthesis of diverse derivatives gives the opportunity to check the influence of the substituent for further investigations of metalloid tin cluster compounds. [ABSTRACT FROM AUTHOR]

Three multi‐shell metalloid gold clusters of the composition Au32(R3P)12Cl8 (R=Et, nPr, nBu) were synthesized in a straightforward fashion by reducing R3PAuCl with NaBH4 in ethanol. The Au32 core comprises two shells, with the inner one constituting a tilted icosahedron and the outer one showing a distorted dodecahedral arrangement. The outer shell is completed by eight chloride atoms and twelve R3P groups. The inner icosahedron shows bond lengths typical for elemental gold while the distances of the gold atoms in the dodecahedral arrangement are in the region of aurophilic interactions. Quantum‐chemical calculations illustrate that the Jahn–Teller effect observed within the cluster core can be attributed to the electronic shell filling. The easily reproducible synthesis, good solubility, and high yields of these clusters render them perfect starting points for further research. Gold cluster triumvirate: Three gold clusters Au32(R3P)12Cl8 were synthesized, obtained in good yields in crystalline form, and structurally characterized. They show the same Jahn–Teller‐distorted core motif consisting of an Au12 icosahedron inside an Au20 dodecahedron, and differ only in the length of the alkyl chains of the respective phosphine ligands and their solubility properties. [ABSTRACT FROM AUTHOR]