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We report the synthesis and characterization of ionic compounds [(thf)4YbI]2[Ge9(Hyp)3]2 (1) and [(thf)5LnI]4[Ge9(Hyp)3]4 (Ln = Eu (2), Sm (3)), (Hyp = Si(SiMe3)3). All compounds were examined by UV-Vis spectroscopy and a blue luminescence of Eu2+ was found. The solid state magnetic measurements of complexes 2 and 3 confirmed the presence of divalent lanthanides. [ABSTRACT FROM AUTHOR]

We present a series of new intermetalloid clusters (R3P)CuGe9((Hyp)3, (R=Me, Et, iPr, nBu, tBu) (Hyp=Si(SiMe3)3) (R3P)AuGe9(Hyp)3MGe9(Hyp)3 (R=Ph, Me; M=Au, Cu). In conjunction with already known clusters, these give new insights into the bonding situation of metal bridged Ge9 clusters as well as a better understanding of the formation of these clusters. Additionally, the intermetalloid clusters with the smallest phosphine PMe3 show new bonding motives. [ABSTRACT FROM AUTHOR]

The reaction of a metastable SnCl solution with KR (R = Si(SiMe3)2(SitBuMe2) = HyptBuMe2 or Si(SiMe3)2(SiEt3) = HypEt3) gives the metalloid tin cluster [Sn10R4]2− in partly good yields. The tin clusters are in the solid state as well in solution coordinated by a potassium cation, leading first of all to a more static compound and novel coordination polymers in the solid state. Additionally, the coordination of the potassium cation strongly increases the stability of the cluster in solution. This higher stability is thereby an important prerequisite for future investigation of this open shell metalloid tin cluster. [ABSTRACT FROM AUTHOR]

We report the synthesis, structure and magnetic properties of the first rare earth complexes of metalloid group 14 clusters [(thf)2Ln(Ge9Hyp3)2] (Ln = Eu, Sm, Hyp = Si(SiMe3)3). X-Ray crystallographic analysis and DFT calculations reveal a novel η2-coordination mode of the Ge9Hyp3 units and a slight distortion of the Ge9 cage. [ABSTRACT FROM AUTHOR]

The reaction of Et3PAuCl with NaBH4 in EtOH leads to the metalloid gold cluster Au32(Et3P)12Cl8 (Au32) or Au54(Et3P)18Cl12 (Au54) depending on the work-up procedure of the reaction mixture. The molecular structure of Au54 is determined by X-ray diffraction and can be described as a fusion of two Au32 clusters showing a similar solubility. The metalloid cluster Au54 can be either described by a shell model or as a combination of tetrahedral Au4X units (X = Cl, Et3P); edge and face sharing, whereas tetrahedral Au4 units are a central motif in gold cluster chemistry. This novel Au54 gold cluster gives another unique insight into the formation or decomposition process of metalloid clusters, indicating that Au32 and Au54 form from a single yet unknown cluster source. [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]

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 reaction of a metastable Sn(I)Cl solution with NaSitBu3 leads to the largest metalloid group 14 cluster Sn20(SitBu3)10Cl2, in which the arrangement of the tin atoms in the cluster can be seen as a raspberry-like cluster of cluster arrangement, giving further insight into the process of the formation of a metalloid tin cluster from molecular precursors. Quantum chemical calculations further indicate that the arrangement of the tin atoms in the cluster core can be highly flexible, leading to the decomposition of the Sn20 cluster into smaller Sn10 units when the right substituent is applied. [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]

Abstract: Heating a metastable solution of GeIBr to room temperature led to the first structurally characterized metalloid subhalide cluster Ge14Br8(PEt3)4 (1). Furthermore 1 can be seen as the first isolated binary halide cluster on the way from GeIBr to elemental germanium, giving insight into the complex reaction mechanism of its disproportionation reaction. Quantum chemical calculations further indicate that a classical bonding situation is realized within 1 and that the last step of the formation of 1 might include the trapping of GeBr2 units. [ABSTRACT FROM AUTHOR]

The reaction of the metalloid tin cluster [Sn10(Hyp)4]2− with (Ph3P)Au-SHyp (Hyp = Si(SiMe3)3) gave an intermetalloid cluster [Au3Sn18(Hyp)8]−1, which is the longest intermetalloid chain compound of tin to date. 1 shows a structural resemblance to binary AuSn phases, which is expected for intermetalloid clusters. [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]

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]

The influence of the stabilizing ligand on the physical and chemical properties of a metalloid cluster compound is important for nanotechnology as metalloid clusters are ideal model compounds for metal nanoparticles. Here we present the synthesis of a differently substituted metalloid {Ge9R3}− cluster: {Ge9[Si(SiMe3)2(SiPh3)]3}− 1, which is obtained in good yield by the reaction of K4Ge9 with ClSi(SiMe3)2(SiPh3). 1 is characterized via NMR and mass spectrometry, but crystallization is hindered. However, the reaction with HgCl2 gives the neutral compound HgGe18[Si(SiMe3)2(SiPh3)]6 2, which can be crystallized and structurally characterized. The presented results are a first step for the investigation of the ligand's influence on the properties of a metalloid germanium cluster compound. [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]

For the synthesis of metalloid cluster compounds of tin applying the disproportionation reaction of subvalent metastable Sn(I) halides, Si(SiMe3)3 proved to be the ligand with the highest synthetic potential. However, degradation of the Si(SiMe3)3 ligand can also lead to cluster enlargement where additional silicon atoms are incorporated into the cluster core. Here we describe the structure and bonding of the novel anionic cluster compound {Sn10Si(SiMe3)2[Si(SiMe3)3]4}2- 5, where such a degradation has taken place. Additionally, requirements for the formation of 5 are discussed. [ABSTRACT FROM AUTHOR]

The disproportionation reaction of the subvalent metastable halide SnCl proved to be a powerful synthetic method for the synthesis of metalloid cluster compounds of tin. Now we present the synthesis and structural characterization of the anionic metalloid cluster compound [Sn9[Si(SiMe3)3]2]2-3 where the oxidation state of the tin atoms is zero. Quantum chemical calculations as well as Mössbauer spectroscopic investigations show that three different kinds of tin atoms are present within the cluster core. Compound 3 is highly reactive as shown by NMR investigations, thus being a good starting material for further ongoing research on the reactivity of such partly shielded metalloid cluster compounds. [ABSTRACT FROM AUTHOR]

The disproportionation reaction of the subvalent metastable halide SnBr proved to be a powerful synthetic method for the synthesis of metalloid cluster compounds of tin. Hence, the neutral metalloid cluster compound Sn10[Si(SiMe3)3]6 (3) was synthesized from the reaction of SnBr with LiSi(SiMe3)3. In the course of the reaction anionic clusters might also be present, and we now present the first anionic cluster compound {Sn8E[Si(SiMe3)3]3}- (E = Si, Sn), where one position in the cluster core is occupied by a silicon or a tin atom, giving further insight into structural variations of E9 cages in metalloid group 14 cluster compounds. [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]

We present a series of new intermetalloid clusters (R3P)CuGe9((Hyp)3, (R=Me, Et, iPr, nBu, tBu) (Hyp=Si(SiMe3)3) (R3P)AuGe9(Hyp)3MGe9(Hyp)3 (R=Ph, Me; M=Au, Cu). In conjunction with already known clusters, these give new insights into the bonding situation of metal bridged Ge9 clusters as well as a better understanding of the formation of these clusters. Additionally, the intermetalloid clusters with the smallest phosphine PMe3 show new bonding motives. [ABSTRACT FROM AUTHOR]