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1.
Inorg Chem ; 2020 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-32578989

RESUMO

Reaction of the Cu(I) sources, [Cu5](Mes)5 and [(iDipp)CuOtBu] (Mes = mesityl; iDipp = 1,3-bis(2,6-diisopropylphenyl)-1H-imidazol-2-ylidene) with the Zn(I) complex [Zn2](Cp*)2 leads to a mixture of intermetallic Cu/Zn clusters with a distribution of species that is dependent on the stoichiometric ratio of the reactants, the reaction time, as well as the temperature. Systematic and careful investigation of the product mixtures rendered the isolation of two new clusters possible, i.e., the Zn-rich, red cluster 1, [CuZn10](Cp*)7 = [Cu(ZnZnCp*)3(ZnCp*)4], as well as the Cu-rich, dark-green cluster 2 [Cu10Zn2](Mes)6(Cp*)2. Structure and bonding of these two species was rationalized with the help of density functional theory calculations. Whereas 1 can be viewed as an 18-electron Cu center coordinated to four ZnCp* and three ZnZnCp* one-electron ligands (with some interligand bonding interaction), compound 2 is better to be described as a six-electron superatom cluster. This unusual electron count is associated with a prolate distortion from a spherical superatom structure. This unexpected situation is likely to be associated with the ZnCp* capping units that offer the possibility to strongly bind to the top and the bottom of the cluster in addition to the bridging mesityl ligands stabilizing the Cu core of the cluster.

2.
Chemistry ; 26(30): 6812-6819, 2020 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-32119154

RESUMO

The lithium phosphidoaluminate Li9 AlP4 represents a promising new compound with a high lithium ion mobility. This triggered the search for new members in the family of lithium phosphidotrielates, and the novel compounds Li3 AlP2 and Li3 GaP2 , obtained directly from the elements via ball milling and subsequent annealing, are reported here. It was unexpectedly found through band structure calculations that Li3 AlP2 and Li3 GaP2 are direct band gap semiconductors with band gaps of 3.1 and 2.8 eV, respectively. Rietveld analyses reveal that both compounds crystallize isotypically in the orthorhombic space group Cmce (no. 64) with lattice parameters of a=11.5138(2), b=11.7634(2) and c=5.8202(1) Šfor Li3 AlP2 , and a=11.5839(2), b=11.7809(2) and c=5.8129(2) Šfor Li3 GaP2 . The crystal structures feature TrP4 (Tr=Al, Ga) corner- and edge-sharing tetrahedra, forming two-dimensional ∞ 2 T r P 2 3 - layers. The lithium atoms are located between and inside these layers. The crystal structures were confirmed by MAS-NMR spectroscopy.

3.
Artigo em Inglês | MEDLINE | ID: mdl-31917887

RESUMO

Polymeric 1 ∞ [Bi]- in KBi⋅NH3 has planar zigzag chains with two-connected Bi atoms and metallic properties, whereas KBi, which has helical chains of Bi atoms, is semiconducting. The isomerization of the Bi chain is induced by solvate molecules. In the novel layered solvate structure uncharged 2 ∞ [KBi] layers are separated by intercalated NH3 molecules. These layers are a structural excerpt of the iso(valence)electronic CaSi, whose metallic properties arise from the planarity of the zigzag chain of Si atoms. Computational studies support this view, they show an anisotropic metallic behavior along the Bi chain. Electron delocalization is also found in the new cyclic anion [Bi6 ]4- isolated in K2 [K(18-crown-6)]2 [Bi6 ]⋅9 NH3 . Although [Bi6 ]4- should exhibit one localized double bond, electron delocalization is observed in analogy to the lighter homologues [P6 ]4- and [As6 ]4- . Both compounds were characterized by single-crystal X-ray structure determination.

4.
Angew Chem Int Ed Engl ; 59(14): 5665-5674, 2020 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-31825547

RESUMO

Solid electrolyte materials are crucial for the development of high-energy-density all-solid-state batteries (ASSB) using a nonflammable electrolyte. In order to retain a low lithium-ion transfer resistance, fast lithium ion conducting solid electrolytes are required. We report on the novel superionic conductor Li9 AlP4 which is easily synthesised from the elements via ball-milling and subsequent annealing at moderate temperatures and which is characterized by single-crystal and powder X-ray diffraction. This representative of the novel compound class of lithium phosphidoaluminates has, as an undoped material, a remarkable fast ionic conductivity of 3 mS cm-1 and a low activation energy of 29 kJ mol-1 as determined by impedance spectroscopy. Temperature-dependent 7 Li NMR spectroscopy supports the fast lithium motion. In addition, Li9 AlP4 combines a very high lithium content with a very low theoretical density of 1.703 g cm-3 . The distribution of the Li atoms over the diverse crystallographic positions between the [AlP4 ]9- tetrahedra is analyzed by means of DFT calculations.

5.
Chem Sci ; 10(39): 9130-9139, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31827755

RESUMO

Unsaturated silicon clusters with only partial substitution, and thus, "naked" Si atoms are well studied species as they are proposed intermediates in gas-phase deposition processes. Although a remarkable number of stable molecular clusters has been reported, they are typically still obtained by multi-step syntheses. Herein we introduce a newly developed synthetic approach which led to the formation of the anionic species {Si(TMS)3}3Si9 - (1a) and {Si(TMS)3}2Si9 2- (1b), and an extension of this synthetic protocol resulted in the first covalent attachment of ligands through metal atoms to these clusters, (SnCy3)3Si9 - (2a) and (SnCy3)2Si9 2- (2b). The influence of the substituents on the electron localization in the central Si9 unit is analyzed by means of intrinsic bond orbital (IBO) analysis and partial atomic charge distribution. The IBO analyses reveal a new type of delocalization including 5-center-6-electron besides 3-center-2-electron bonds. The Raman spectra of 1b and 2b allow an assignment of the Si-Si intra-cluster vibrations by comparison to calculated (DFT-PBE0) spectra. The anions are formed in a one-step synthesis from binary K12Si17 which can easily be obtained by fusing the elements K and Si. The anions are characterized by ESI mass spectrometry and comprehensive NMR studies (1H, 13C, 29Si, 119Sn). Attempts to crystallize 1a and 2a as their (K-222crypt)+ salts yielded after the loss of one of the substituents single crystals containing 1b and 2b. The single crystal X-ray structure analyses reveal the presence of anionic siliconoids with surfaces of seven unsubstituted silicon atoms.

6.
Inorg Chem ; 58(19): 13293-13298, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31532208

RESUMO

Anionic clusters with a homoatomic [Ge9] core are species with Ge atoms in low oxidation states. In this study their reaction with early-transition-metal complexes was investigated. We report the syntheses of Ti(III) complexes of silylated [Ge9] Zintl clusters, which are rare examples of molecular complexes with Ge-Ti interactions. The neutral species [Cp2(MeCN)Ti(η1-Ge9{Si(TMS)3}3)] (1) was obtained by the reaction of K[Ge9{Si(TMS)3}3] with [Cp2TiCl]2 in toluene as dark orange crystals, whereas the reaction of K2[Ge9{Si(TMS)3}2] with [Cp2TiCl]2 in thf and subsequent recrystallization from toluene resulted in dark green crystals of K3[Cp2Ti(η1-Ge9{Si(TMS)3}2)2] (2). Compound 2 contains the trianion [Cp2Ti(η1-Ge9{Si(TMS)3}2)2]3- (2a), which can be described either as a [Cp2Ti]+-bridged [Ge9{Si(TMS)3}2]2- dimer or as a heavily distorted tetrahedral Ti(III) complex bearing two germanide cluster ligands. Both compounds display donor-acceptor interactions between single Ge vertex atoms of the [Ge9] clusters and Ti(III). Compounds 1 and 2 were characterized by single-crystal X-ray diffraction, EPR spectroscopy, and elemental analysis.

7.
Chem Commun (Camb) ; 55(81): 12156-12159, 2019 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-31552931

RESUMO

Homoatomic cluster aggregation is a versatile route to build up atom-precise nano structures. In this work we describe the first connection of four Ge9 clusters to a single atom: in K6[Zn{η1-Ge9(Hyp)2}4]·10.5 Tol four bis-silylated Ge9 clusters are linked via one central Zn atom. Furthermore we report on the bare Ge9 cluster in (NH3)3Zn-Ge9-Zn(NH3)3·11NH3, which reveals two possible connectivity sites due to the NH3 leaving groups at the Zn atoms. Both complexes can be regarded as analogue building motifs for hypothetical tetrel element structures anticipated before with Zn atoms taking the role of four-connected tetrel atoms.

8.
J Am Chem Soc ; 141(36): 14200-14209, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31403777

RESUMO

Solid electrolytes with superionic conductivity are required as a main component for all-solid-state batteries. Here we present a novel solid electrolyte with three-dimensional conducting pathways based on "lithium-rich" phosphidosilicates with ionic conductivity of σ > 10-3 S cm-1 at room temperature and activation energy of 30-32 kJ mol-1 expanding the recently introduced family of lithium phosphidotetrelates. Aiming toward higher lithium ion conductivities, systematic investigations of lithium phosphidosilicates gave access to the so far lithium-richest compound within this class of materials. The crystalline material (space group Fm3m), which shows reversible thermal phase transitions, can be readily obtained by ball mill synthesis from the elements followed by moderate thermal treatment of the mixture. Lithium diffusion pathways via both tetrahedral and octahedral voids are analyzed by temperature-dependent powder neutron diffraction measurements in combination with maximum entropy method and DFT calculations. Moreover, the lithium ion mobility structurally indicated by a disordered Li/Si occupancy in the tetrahedral voids plus partially filled octahedral voids is studied by temperature-dependent impedance and 7Li NMR spectroscopy.

9.
Angew Chem Int Ed Engl ; 58(37): 12908-12913, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31298780

RESUMO

Endohedral clusters count as molecular models for intermetallic compounds-a class of compounds in which bonding principles are scarcely understood. Herein we report soluble cluster anions with the highest charges on a single cluster to date. The clusters reflect the close analogy between intermetalloid clusters and corresponding coordination polyhedra in intermetallic compounds. We now establish Raman spectroscopy as a reliable probe to assign for the first time the presence of discrete, endohedrally filled clusters in intermetallic phases. The ternary precursor alloys with nominal compositions "K5 Co1.2 Ge9 " and "K4 Ru3 Sn7 " exhibit characteristic bonding modes originating from metal atoms in the center of polyhedral clusters, thus revealing that filled clusters are present in these alloys. We report also on the structural characterization of [Co@Ge9 ]5- (1a) and [Ru@Sn9 ]6- (2a) obtained from solutions of the respective alloys.

10.
Chemistry ; 25(53): 12349-12356, 2019 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-31231877

RESUMO

The synthetic approach towards molecules that contain Ge atoms with oxidation state 0, and which are exclusively connected to other Ge atoms, is explored by using anionic clusters extracted from binary solids. Besides providing a novel variable method for the introduction of alkenyl moieties to [Ge9 ] cluster compounds, this work expands the spectrum of mixed-functionalized [Ge9 ] cluster anions, which are suitable for the straightforward synthesis of zwitterionic compounds upon coordination to metal cations. In detail, the synthesis of a series of mixed-functionalized [Ge9 ] clusters is reported, including [Ge9 {Si(TMS)3 }3 PRRI ] (R=tBu, RI =(CH2 )3 CH=CH2 ; 2) and [Ge9 {Si(TMS)3 }2 PRRI ]- (R and RI : alkyl, alkenyl, aryl, aminoalkyl; 3 a to 11 a, TMS: (trimethyl)silyl). In 2 and 3 a, pentenyl functionalization of the [Ge9 ] clusters was achieved by reaction of the novel chlorophosphine tBu{(CH2 )3 CH=CH2 }PCl (1) with silylated [Ge9 ] clusters. Furthermore, the reactivity of the cluster anions 3 a to 11 a towards NHCDipp MCl (NHCDipp =1,3-di(2,6-diisopropylphenyl)imidazolylidine; M=Cu, Ag) showed a dependency on the steric demand of the phosphine either zwitterions (3-MNHCDipp to 7-MNHCDipp ) featuring P-M interactions are formed, or Ge-M coordination (8-MNHCDipp to 11-MNHCDipp ) occurs. For M=Ag, the formation of zwitterionic complexes was unequivocally proven by NMR investigations showing 1 J(31 P-107 Ag/109 Ag) spin-spin coupling.

11.
Inorg Chem ; 58(5): 3256-3264, 2019 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-30741546

RESUMO

The coordination of Ge9 Zintl clusters at (carbene)CuI moieties is explored, and the complexes [(CAAC)Cu]2[η3-Ge9{Si(TMS)3}2] (1), (CAAC)Cu[η3-Ge9{Si(TMS)3}3] (2), and (MIC)Cu[η3-Ge9{Si(TMS)3}3] (3) are compared with their known N-heterocyclic carbene (NHC) derivatives (A and B), where CAAC = cyclic (alkyl)amino carbene, MIC = mesoionic carbene, and TMS = trimethylsilane. In analogy to the NHC derivatives, the synthesis of 1-3 proceeds by single-step reactions of (CAAC)CuCl or (MIC)CuCl with the [Ge9R2]2- and [Ge9R3]- [R = Si(TMS)3] cluster ligands, respectively, and yields complexes of (carbene)CuI (carbene = CAAC, MIC) moieties exhibiting η3-coordination modes of the Ge9 deltahedron to the Cu atom. In 1, [Ge9R2]2- acts as a η3-bridging unit for two (CAAC)CuI moieties, and 2 and 3 feature single (carbene)CuI (CAAC and MIC) fragments η3-connected to [Ge9R3]- units. Analysis of the bond lengths in comparison with known examples shows a bond expansion within the coordinated Ge3 triangular faces for all (carbene)CuIGe9 complexes (carbene = NHC, MIC, CAAC). All compounds are characterized by single-crystal X-ray diffractometry, NMR spectroscopy [1H, 13C{1H}, and 29Si{1H}], electrospray ionization mass spectometry, elemental analysis (C, H, and N), and for the first time also by IR and Raman investigations (for 2 and 3). The new complexes add to the known NHC derivatives and extend the exploration of Ge9 clusters with carbene ligands at CuI atoms.

12.
Nanoscale ; 11(4): 2048-2055, 2019 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-30644939

RESUMO

Fabrication of porous, foam-like germanium-based (Ge-based) nanostructures is achieved with the use of the amphiphilic diblock copolymer polystyrene-b-polyethylene oxide as structure directing agent. Basic concepts of block copolymer assisted sol-gel synthesis are successfully realized based on the [Ge9]4- Zintl clusters as a precursor for Ge-based thin films. Material/elemental composition and crystalline Ge-based phases are investigated via X-ray photoelectron spectroscopy and X-ray diffraction measurements, respectively. Poor-good solvent pair induced phase separation leads to pore sizes in the Ge-based films up to 40 nm, which can be tuned through a change of the molar mixing ratio between polymer template and precursor as proven by grazing incidence small angle X-ray scattering and scanning electron microscopy.

13.
Chemistry ; 24(72): 19171-19174, 2018 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-30393897

RESUMO

Neutral and anionic silicon clusters (siliconoids) are regarded as important model systems for bulk silicon surfaces. For 25 years their formation from binary alkali metal silicide phases has been proposed, but experimentally never realized. Herein the silylation of a silicide, leading to the anionic siliconoids (Si(tBu)2 H)3 Si9 - (1 a) and (Si(tBu)2 H)2 Si9 2- (2 a) with the highest known number of ligand-free silicon atoms is reported for the first time. The new anions are obtained in a one-step reaction of K12 Si17 /NH3 (liq.) and Si(tBu)2 HCl/THF. Electrospray ionization spectrometry and 1 H, 13 C, 29 Si, as well as 29 Si-HMBC (heteronuclear multiple bond correlation) NMR spectroscopy, confirm the attachment of three silyl groups at a [Si9 ]4- cluster under formation of 1 a, in accordance with calculated NMR shifts. During crystal growth the siliconoid di-anion 2 a is formed. The single-crystal X-ray structure determination reveals that two silyl groups are connected to the deltahedral Si9 cluster core, revealing seven unsubstituted exposed silicon cluster atoms with a hemispheroidal coordination. The negative charges -1 and -2 are delocalized over the six and seven siliconoid Si atoms in 1 a and 2 a, respectively.

14.
Chem Commun (Camb) ; 54(87): 12381-12384, 2018 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-30328416

RESUMO

The first example of a protonated and a rare example of a metal complex of the tetrahedral tetrel cluster anion [Ge4]4- was obtained from a solution of K6Rb6Ge17 in liquid ammonia in the presence of ZnPh2 and [18]crown-6. In [K([18]crown-6)][Rb([18]crown-6)]2[HGe4ZnPh2]·8NH3 (1) one ZnPh2 molecule and one H atom are bound to opposite, significantly elongated edges of a distorted Ge4 tetrahedron. DFT calculations confirm the experimentally found interatomic distances and reveal a structural proof of a three-center two-electron Ge-H-Ge bond.

15.
Angew Chem Int Ed Engl ; 57(44): 14372-14393, 2018 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-30098108

RESUMO

Atom-precise, ligand-stabilized metalloid clusters have emerged as outstanding model systems to study fundamental structure and bonding situations of compositionally related molecules and extended solid phases. However, this fascinating field of research is still largely restricted to homometallic and pseudo-heterometallic systems of closely related d-block metals. In this review, we will highlight our own and others' efforts to project the structural and compositional diversity of intermetallics with dissimilar d- and p-block metal combinations, particularly the Zintl and Hume-Rothery phases, onto the molecular level in order to bridge the still gaping chasm between heterometallic molecular coordination chemistry and solid-state intermetallics. Herein, fundamental synthetic approaches, as well as structural and electronic properties of thus accessible "molecular alloys" will be addressed, and placed against their exceptional position as intermediates on the way to nanomaterials.

16.
Angew Chem Int Ed Engl ; 57(39): 12950-12955, 2018 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-30009505

RESUMO

Polyanionic silicon clusters are provided by the Zintl phases K4 Si4 , comprising [Si4 ]4- units, and K12 Si17 , consisting of [Si4 ]4- and [Si9 ]4- clusters. A combination of solid-state MAS-NMR, solution NMR, and Raman spectroscopy, electrospray ionization mass spectrometry, and quantum-chemical investigations was used to investigate four- and nine-atomic silicon Zintl clusters in neat solids and solution. The results were compared to 29 Si isotope-enriched samples. 29 Si-MAS NMR and Raman shifts of the phase-pure solids K4 Si4 and K12 Si17 were interpreted by quantum-chemical calculations. Extraction of [Si9 ]4- clusters from K12 Si17 with liquid ammonia/222crypt and their transfer to pyridine yields in a red solid containing Si9 clusters. This compound was characterized by elemental and EDX analyses and 29 Si-MAS NMR and Raman spectroscopy. Charged Si9 clusters were detected by 29 Si NMR in solution. 29 Si and 1 H NMR spectra reveal the presence of the [H2 Si9 ]2- cluster anion in solution.

17.
Angew Chem Int Ed Engl ; 57(44): 14509-14513, 2018 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-29998525

RESUMO

Herein we report on the synthesis of the first multiple phosphine-substituted nonagermanide clusters in a one-step reaction from K4 Ge9 . Their reactions towards various transition metal complexes show a large variety of reactive sites. The novel threefold phosphine-functionalized [Ge9 ] clusters [Ge9 {PRRI }3 ]- {R: Ni Pr2 ; RI : Ni Pr2 (1 a) or t Bu (2 a)} are obtained by reaction of pristine [Ge9 ]4- clusters with the respective chlorophosphines. Subsequent reactions with NHCDipp CuCl yield neutral compounds (NHCDipp Cu)[Ge9 {P(Ni Pr2 )2 }3 ] (3) and (NHCDipp Cu)[Ge9 {P(Ni Pr2 )t Bu}3 ] (4), respectively. The reaction of neutral compound 3 with Cr(CO)5 (thf) yields the first uncharged fivefold substituted [Ge9 ] cluster (NHCDipp Cu)2 [Ge9 {P(Ni Pr2 )2 }2 Cr(CO)5 ] (5) via a ligand exchange reaction at the [Ge9 ] cluster core. Compounds 3 and 5 are characterized by single crystal structure determination.

18.
Chemistry ; 24(36): 9009-9014, 2018 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-29756360

RESUMO

The direct acylation of Ge9 Zintl clusters by the reaction of K[Ge9 {Si(SiMe3 )3 }3 ] with acyl chlorides in hexane or toluene solutions is presented, leading to the neutral, carbonyl-derivatized products [{Si(SiMe3 )3 }3 Ge9 (CO)R'] (R'=Me, iPr, tBu, Ph, Bz, cyclopropylmethyl, phenethyl, 4-vinylphenyl). This reaction is applicable to a wide range of acyl chlorides and allows for diverse functionalization of Ge9 Zintl clusters. [{Si(SiMe3 )3 }3 Ge9 (CO)tBu] readily releases CO at ambient conditions under formation of [{Si(SiMe3 )3 }3 Ge9 tBu]. This temperature-dependent decarbonylation most likely proceeds via a radical Norrish-type I α-bond cleavage. Except for R'=tBu and Bz all obtained acyl-derivatized Ge9 cluster compounds do not release CO even at elevated temperatures. All compounds were characterized by NMR spectroscopy. [{Si(SiMe3 )3 }3 Ge9 (CO)R'] (R'=tBu, Ph, Me, iPr) as well as [{Si(SiMe3 )3 }3 Ge9 tBu] were further structurally characterized by single crystal X-ray diffraction.

19.
Dalton Trans ; 47(10): 3223-3226, 2018 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-29411846

RESUMO

The first alkenyl-functionalized, uncharged deltahedral germanium clusters [{Si(SiMe3)3}3Ge9(CH2)nCH[double bond, length as m-dash]CH2] (n = 1 or 3) comprising five Ge0 atoms are presented. All compounds were NMR-spectroscopically and mass-spectrometrically characterized. [{Si(SiMe3)3}3Ge9(CH2)3CH[double bond, length as m-dash]CH2] was further characterized by X-ray structure analysis and Raman spectroscopy. Temperature-dependent NMR studies reveal dynamic behavior for both compounds in solution at room temperature. The propenyl derivative [{Si(SiMe3)3}3Ge9CH2CH[double bond, length as m-dash]CH2] undergoes fast decomposition in solution. The possibility of the comparatively stable pentenyl-substituted Ge9 cluster as a candidate for follow-up reactions is highlighted.

20.
Chemistry ; 24(16): 4103-4110, 2018 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-29322565

RESUMO

The reaction of [(Ge9 {Si(TMS)3 }2 PtBu2 )]- with NHCMes CuCl yields [(Ge9 {Si(TMS)3 }2 )(tBu2 P)]Cu(NHCMes ) (1), which is a new derivative of the recently reported monomeric zwitterionic tetrel cluster compounds [(Ge9 {Si(TMS)3 }2 )(tBu2 P)]M(NHCDipp ) (M: Cu, Ag, Au). By contrast, the reaction of the same anion [(Ge9 {Si(TMS)3 }2 PtBu2 )]- with the more labile copper phosphine complex Cy3 PCuCl leads to the formation of [Ge9 {Si(TMS)3 }2 {(tBu)2 PCu}2 Ge9 {Si(TMS)3 }2 ] (2), which is a neutral dimeric twofold-bridged [Ge9 ] cluster compound, with the exo-bonded phosphine substituent being involved in the cluster bridging. In case of the presence of sterically more demanding phosphines in [Ge9 {Si(TMS)3 }2 PR2 ]- [R: Mes (3) and NiPr2 (4)], reactions with NHCDipp CuCl yielded the complexes NHCDipp Cu[η3 -Ge9 {Si(TMS)3 }2 (PR2 )] [R: Mes (5) and NiPr2 (6)], comprising exclusively Cu-Ge bonds. Compounds 5 and 6 show varying reactivity in dependence of the identity of the phosphine group and represent the first examples of fourfold-substituted [Ge9 ] clusters with three different ligands bound to the [Ge9 ] cluster core. All compounds were characterized by 1 H, 13 C, 31 P, and 29 Si NMR spectroscopy. Additionally, compounds 3 and 4 were analyzed by ESI-MS, and the structures of compounds 1, 2, and 5 were characterized by single-crystal X-ray diffraction.

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